15. 07. 2026 Will Steen

Does the Meg exist? Here’s what scientists actually found.

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Yes, the Meg exists. No, it isn’t the one you are thinking of.

On the 15^th November 1976, the US Naval Research ship with the catchy name AFB-14 was on a mission 42 km (26 miles) off the coast of Oahu, Hawaii. Suddenly, the sea anchor, a parachute-like tool for stabilising a ship at sea, caught and pulled. The crew hauled it up to find 4.5m (14.7 ft) of fish.

The crew brought the 750kg (1,653.5 lbs) shark on board with “much difficulty” and brought it back to Kaneohe Bay, tying it alongside the dock overnight.

The shark was so heavy it needed a Navy crane to lift it. During the operation the caudal fin (tail) broke off, dropping the shark into the water where it needed recovery by divers. Finally, though, it could be examined by the experts.

Amongst the first on the scene was the director of Waikiki aquarium, Leighton Taylor. Along with other marine biologists, they recognised a species that was entirely new to science.

Leighton Taylor had the honour of naming the species, and settled on Megachasma pelagios – from the Greek meaning “the large yawning hole of the open Ocean”. It is known more commonly as the megamouth shark – the largest shark you’ve probably never heard of.

50 years on, what do we know about this elusive shark? And after discovering this, does that mean there could be other huge shadows lurking in the depths?

US Navy Ship retrieving the first megamouth shark. — *Photo via California Academy of Sciences*

What does the megamouth shark look like?

As the name suggests, the main feature of the megamouth is its vast mouth, which is housed in a huge bulbous head. This mouth is full of tiny teeth, not big white sharp things like its cousins, leaving the megamouth with a gummy grin. The tail also deserves a mention – similar to the thresher shark, the megamouth has a large upper lobe of its tail, which can be as big as a person.

The megamouth is the third biggest species of shark behind the two other filter feeding sharks – the whale shark (Rhincodon typus) and the basking shark (Cetorhinus maximus).

Megamouth sharks can reach sizes of up to 8.2m long, maybe up to 9m, with females reaching larger sizes.

Megamouth shark, posted by Ocean Generation. — *Photo by Bruce Rasner*

What is filter feeding?
Filter feeding is utilised by animals of all different shapes and sizes in the Ocean. The premise is to filter out the tiny algae and animals floating in the water. Whales do this using their baleen, flamingos with their special beaks, and most forage fish have gill rakers, catching anything in the water moving over their gills.

Whale sharks, basking sharks and megamouth sharks are filter feeding sharks. — *Megamouth shark photo by Bruce Rasner*

On the 14 November 2023, a stranding gave us amazing insight into the reproduction of the large-lipped fish. A female megamouth was washed ashore while giving birth. 1 pup was found next to her, with 6 more in her belly. They measured 1.65m to 1.83 m (5.41-6 ft) long. That is approximately one Ocean Generation Marine Science Officer (not a scientifically accepted measurement) long.

The first descriptions of megamouths are less than kind. A “soft, flabby body and fins, low-flow branchial filter apparatus and small gill openings”. Taylor suggested that this pointed to an animal far less active than the other filter feeding sharks.

To confirm this, we had to find a live one.

When was the first live megamouth shark found?

On October 21, 1990, the sixth megamouth shark ever was found, caught up in a drift gill net off California. The big difference with megamouth number 6? He was still alive. We shall name him Luis, after the Luiseno people indigenous to the Californian coast he was caught off.

When the fisherman, Otto Elliot of the vessel Moonshiner, pulled up Luis, he recognised that this was a rare find. He managed to get a rope around the peduncle of the shark (the base of the tail) and towed it for five and half hours back to harbour.

Otto was asked by scientists to keep the shark alive until measurements had been taken, and so Luis was left tied by a short tail rope in the harbour. Quite remarkably, Luis survived.

The researchers formulated a release plan, and towed Luis back out to open water. Here, he become the first live megamouth shark to be filmed, and was released with a tag, giving us nearly 51 hours of insight into the lives of these mysterious sharks.

What did we learn from tagging megamouth number 6?

The research vessel R/V Discovery was assigned to tracking Luis, ensuring it was collecting data from his tag. It wasn’t difficult to keep up – Luis cruised at around 1.15 kilometre (0.73 miles per hour), although a current going against him led scientists to estimate his true speed: 1.5-2.1 km/h (0.73-1.3 miles). As predicted by the initial discovery, Luis was no speedster.

Luis showed us that megamouth sharks follow a crepuscular vertical migration: crepuscular meaning at dawn and dusk, vertical migration meaning moving up and down. He spent his days in the depths around 150m (492 ft), returning to shallow waters of around 20m (65.6 ft) during the nighttime. Luis used the light (or more accurately the dark) to guide his movements: a sharky anti-moth.

Why was he making this migration every day? Could he be chasing food?

What do megamouth sharks eat?

Researchers can use the chemical properties of tissue from an animal to work out where it has been eating, and what it has been eating.

A large study compared the diet and location of 91 megamouth sharks and 90 whale sharks.

Whale sharks tended to eat up the food chain as they got bigger (and older): they moved from phytoplankton to fish to bigger fish and so on. They had a far more varied diet than our mega-mouthed friends.

The very first megamouth was found with a stomach full of krill, and this was no coincidence. Megamouths love krill and jellyfish and that is kind of it. No matter how big they get, they don’t grow out of their krill phase. Imagine being stuck with that food you were obsessed with when you were young, for life.

The researchers also found that male and female megamouths were quite distinctly separated – they were eating in different places.

Why? We aren’t entirely sure yet, the researchers suggested that males may roam further to find mates while females stay in the productive, safer waters near birthing grounds. There is still plenty to find out about these secretive sharks, but why are they so good at remaining hidden?

Why do we not see many megamouth sharks?

The Ocean is huge. Think of an Ocean creature – starfish, seahorse, the famous clownfish (find out how scientifically accurate Finding Nemo actually is here). Chances are, you are thinking of a coastal animal, that we land-dwellers cross paths with regularly.

The megamouth is from a different world, that we are not regular visitors to. During the day, they cruise through the darkness of the twilight zone, and only at night do they come more shallow. There are only nine sightings of megamouths in natural conditions – humans and megamouths don’t overlap.

230 of the 301 sightings (as of June 2026) come from megamouths caught up in fishing gear. And we are seeing more. 170 of the 301 megamouths ever found came in the last ten years, 131 coming in the 40 years before that. Why are we seeing more now?

Given the large portion that are found due to fishing, the increase is likely to be related to fishing. Maybe an increase in fishing activity is seeing more caught, or new equipment at different is catching more megamouths. Or maybe these fisheries have always caught megamouths, but the reporting of the catches has got a lot better. Being aware of our impact on the Ocean is the first step to controlling it.

Anyway, now we know there is a massive, nearly 10m (32.8 ft) shark swimming around out there that we only discovered 50 years ago: there is only one question to follow that.

Is the megalodon still alive and hiding in the deep?

No. There are two main reasons for this.

1. Amount of food – can’t hide the evidence.

An active hunter that is estimated to have been over 24m (78.7 ft) long, the megalodon had huge teeth which it would have used to eat other sharks, fish and whales. Prey species like whales are mostly found in the surface Ocean, increasing the likelihood of even the stealthiest hunter being seen.

If not seen directly, the effects of having a huge hunter would be visible. Bite marks and teeth would be regularly spotted, and they aren’t. We haven’t found a megalodon tooth younger than 3.5 million years old, which is when we think megalodon went extinct.

2. Location – megalodon isn’t hiding in the depths.

We know megalodon was a tropical and subtropical dweller, that thrived in the warm waters. Suggestions that they could be hiding in the cold, dark depths of the Ocean are impossible. Especially when we consider the compound that protects sharks’ cells from the crushing pressures of the deep Ocean stops being effective around 3,000m (1.81 miles), suggesting that sharks absolutely can’t go below 4,000m (2.5 miles) deep.

The megamouth is a big shark, but smaller than megalodon, and eats tiny prey that lives in the pelagic depths (deep, open water). That is why it wasn’t discovered for so long.

Megalodon jaw, posted by Ocean Generation. — *Photo by JJonahJackalope via Wikimedia Commons*

Could there be another huge species of shark still undiscovered?

We can’t rule it out completely (the Ocean is on average 3,682m (2.28 miles) deep – plenty of space for something to hide), but it is unlikely. We understand our Ocean more than ever, and large species would have been found if not by scientists, by the commercial fishing fleets that drag nets through most layers of the Ocean.

The most likely shark hiding out there would be a sleeper shark, similar to the Greenland shark. As the name suggests, these fish like life in the slow lane, cruising the Ocean depths for food. Their un-rushed lifestyle means low demand for food, and they can survive on less food, such as occasional whale falls (read more about how a dead whale means new life in the deep here).

What do we still not know about megamouth sharks?

There is plenty we still have to discover about megamouth sharks. Why are they usually separated like a school disco, the boys and girls staying far apart from each other? Do individuals migrate like whale sharks, or have their favourite spots they stay in? Do they have glowing mouths to attract prey?

How do they hunt? Is it like basking sharks, swimming with mouths agape? Or whale sharks, opening mouths quickly to create suction, drawing prey in? Or something else, more like a whale drawing its large mouth over prey?

The megamouth story is full of mystery and excitement. It also shows us our increasing presence in the Ocean. It does not mean the megalodon is still alive. That mystery has been solved. Trust us.

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Will Steen

The oldest things in the Ocean: Explained.

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7. 07. 2026 Will Steen

The lonely whale: The story of the 52Hz whale

The story of the world's loneliest whale, the 52Hz whale: explained.

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There is a unique whale song echoing through the Ocean, sung by the loneliest whale in the world. What kind of whale is it, and is he actually lonely?

The Ocean used to be thought of as noiseless. Legendary Ocean explorer Jacques Cousteau’s first book was named The Silent World. Swimming comes with ears full of water, muffling the familiar noises of the airy world above.

Only recently, and mostly by accident, have we begun to realise that the Ocean is far from silent. Noisy coral reefs call in larvae to settle, fish grunt and whistle at each other, and snapping shrimp fill the water with a white noise any focus app would be envious of.

The most famous of the Ocean songs is that of the whales.

How we discovered sounds in the Ocean

In the second half of the 20^th century, the Ocean became the frontline of the Cold War. Submarines glided through the depths, carrying enormous destructive power but hidden from sight. In the Ocean, sound matters more than sight.

We began listening to the sounds of our Ocean, to keep track of those sneaky submarines, and discovered a new world we didn’t understand.

In March 1949, R/V Atlantis from Woods Hole Oceanographic Institution picked up some strange noises off the coast of Bermuda that couldn’t be identified. A haunting, eerie noise that could be mistaken for a wolf’s howl over the mountains. The noise was archived, unidentified.

1949 also saw bio acousticians William Schevill and Barbara Lawrence record beluga whales in Saguenay River, Canada. This was the first time that cetacean (whales and dolphin) noise had been identified.

William Schevill was later credited with diverting geopolitical catastrophe:

“Bill helped defuse a tense moment between the USA and Soviet Union during the Cold War. The US military suspected that low frequency blips were being used by the Soviets to locate American submarines, whereas Bill showed these were produced by fin whales (Balaenoptera physalus) hunting prey.”

He wasn’t the only one battling misunderstood Ocean sounds. You can read about how herring farts nearly ended the world here.

In a naval listening station from the late 1950s into the early 1960s, engineer Frank Watlington was listening out for the sounds of submarines in the Atlantic. He would regularly hear rich and emotive melodies echoing around the Bermudian waters. He recognised the sounds as biological and recorded them, hoping to one day identify the singers responsible. He didn’t have to wait long.

Who identified humpback whale song?

In the mid-1960s, a biologist who had focused on echolocation in bats and the hearing of owls turned his attention to Frank’s recordings. His name was Roger Payne, and he was the man who would take the songs of the sea to ears around the world.

Payne analysed the recordings and identified the singers: humpback whales. He published a scientific description of the songs Frank had recorded in 1971, revealing their complex structure and rhythm. But a peer-reviewed scientific paper wasn’t going to make big enough waves (pun intended).

In August 1970, before that paper had been published, Roger Payne released the Songs of the Humpback Whales, a vinyl record just under 35 minutes long of simple, unaltered whale song. The sound took the world by storm.

But even this record paled in comparison to a further honour, bestowed two years earlier in 1977. The Voyager spacecraft left the Earth’s atmosphere with a golden record – a phonograph filled with details about humanity and life on Earth, should the spacecraft ever reach distant life. Track 3 on the record was: “United Nations Greetings/Whale Songs (Various Artists)”.

The songs of the humpbacks were part of the exclusive package: the first man-made materials to leave the solar system, which it managed in 2012. Cetacean song was cemented as a defining element of our planet.

When was the 52 Hz whale first heard?

The wonder of the whale song increased as we listened and learned more – they evolve and spread culturally between and across populations.

Looking through a human lens, we can see similar cultural transmission. Gangnam Style had people trying to sing Korean around the world in 2012, and schools across the Western world are currently shouting “six-sevvvan”. Orcas? They have fashion cycles of wearing salmon as hats.

For humpbacks in the South Pacific, the song writers are off the eastern coast of Australia. Their songs can travel across the largest part of the Ocean to be sung by whales off the coast of Ecuador.

In 1989, a song was recorded that piqued the curiosity of biologist William (Bill) Watkins. The singer became known as the 52 Hertz whale, or as we will use, 52.

To understand why it stood out, we need to first explore sound.

What is sound? What can humans hear?

Sound has two basic properties: frequency and volume. Frequency translates as the pitch we hear – higher pitched sounds have higher frequencies. Frequency is measured in hertz (Hz).

Different animals have different ranges of hearing – some can hear higher frequencies, some lower. Humans are credited with a hearing range of 20Hz-20,000Hz, most sensitive from 2-5,000 Hz. Human speech is approximately 90-135Hz for an adult male and 160-240Hz for an adult female.

You can test your hearing range by listening to this video going through different frequencies – see how high you get.

The humpback whales typically sing in the range of 80-4,000Hz, perfectly within our auditory range. Different animals use different frequencies to communicate: there is a whole world of noise that exists outside of our range of hearing.

Blue and fin whales produce songs of much lower frequency, slipping below our range of hearing (known as infrasound). Others, such as sperm whales and bottlenose dolphins, will use higher frequency clicks in echolocation that we can’t hear (known as ultrasound).

A spectrogram is a
visual representation of sound.

Why is the 52 hertz song so special?

The song we played earlier has been sped up by 10 times so we can properly appreciate it in our range of hearing. It would ordinarily be at the very bottom end of our hearing.

Blue whales will typically call between 10 and 40 Hz, soulful moans that would vibrate your entire body. Fin whale vocalisation is focused around 20Hz pulses, low chirps echoing through the blue.

So when the hydrophones picked up a call focused around 51.75Hz, it didn’t fit. Too high for blue and fin whales, but too low to be a humpback. This whale was singing its own tune.

Listen to the 52 Hz whale recording

Audio courtesy of NOAA PMEL.

For 12 years, Bill Watkins tracked the whale he had dubbed the 52Hz whale, or 52.

The 52 Hz whale sings in a different range to most other whales

What do we know about the 52 Hertz whale?

He published his findings in 2004, tracking the source of the unique song. He made some intriguing discoveries:

Daily travel distance: 52 was a mover. Across the 12 years of seasonal tracking, the whale averaged 47 kilometres every day, and up to 69 km per day.
Seasonal travel distance: A real mover. In the 1992/93 season, 52 travelled just 708km. But across all the tracked seasons, the average distance travelled was 5,518km. In 2002/03, 52 travelled 11,602km. If you ran a marathon every day, it would take you 275 days to cover that distance.
Time spent with other whales: 52, whether intentionally or not, is a solo rider most of the time. The calls were separate from other closely monitored whale species – blue, fin and humpback.
Time spent in one place: 52 is a true nomad. In Bill’s words: “There were no apparent repeated patterns to the whale’s travel”.
Deepening singing: As is normal with whales (and humans) the distinctive voice of 52 deepened by about 2Hz over the study period.
Daily singing time: On some days, 52 sang for over 20 hours.

Map showing the area where the 52HZ whale had been tracked. — *Credit: The Washington Post*

The Symbol: The story of 52 captured the imagination far beyond the scientific community.

The paper caught the eye of a young science journalist, Jon Copley, who covered it in the New Scientist magazine, with the title “Lonely whale’s song remains a mystery”.

A New York Times article by Andrew Revkin built on this theme, painting the picture of a whale roaming the Ocean, calling out in a voice none could recognise, its song going unanswered.

To add melancholia of the whale’s song, Bill Watkins, the great listener and tracker of 52, died in 2004, a month before his paper was published. He would never see the impact his work had.

And it certainly had impact. The idea of a lonely, misunderstood whale resonated (sound joke) with the wider public.

A quick search of lonely whale will uncover endless articles, Facebook groups, TikToks, Reels, and videos exploring the legend of 52 (not all accurately). So, what do we know about this whale?

The Symphony: Is the 52 Hertz whale actually lonely?

Is 52 Hertz lonely? The short answer: we don’t know, but probably not.

The tracking study from Bill Watkins suggests 52 didn’t tend to hang out with other whales, preferring to meander and migrate on their own. But we don’t know how unusual that behaviour is. 52’s unique calls have allowed one of, if not the most detailed long-term tracking studies of any single great whale. It might not be unusual for a whale to spend a lot of time alone.

To clear things up – the other whales can still hear 52. They might just sound a bit strange, like a human talking after inhaling some helium at a birthday party.

One of the lead theories behind the 52 hertz whale is a hybrid between a fin and blue whale. These hybrids have been documented, and fin and blue whales are known to aggregate together on the west coast of North America.

The documentary The Loneliest Whale: Search For 52 set out to find the maverick cetacean singer. The team didn’t prove that 52 was a hybrid but did document a hybrid whale in amongst other blue and fin whales.

This hybrid was documented 20 times over a 16-year period, and at times with over 30 blue whales. IF this is our whale, they have plenty of friends.

Another twist – in 2010, two separate listening stations picked up calls in the 52 hertz range. Could there be another whale hitting the same notes out there? We don’t yet know for sure, but we like to think so.

Different whale species sing at different ranges. Posted by Ocean Generation

What’s next for the whales?

52 is certainly not alone in his sound-based struggles. The Ocean is a much noisier place than it used to be. Ships criss-cross the Ocean carrying food and goods between countries, and they are not subtle. Huge air guns fire, sounding out the seabed to find reserves of oil and gas. Piledrivers pound foundations for offshore constructions such as wind turbines.

The noise they produce creates an acoustic fog, making it harder for whales to communicate. One study estimated that North Atlantic Right Whales have lost over 60% of their communication space. Another shows that they have to ‘shout’ over the noise of propellers churning the whale’s waters. In the aftermath of 9/11, there was a significant drop in ship traffic and thus the noise they produce. Researchers examined whale poo and found less stress-related hormones in the excrement during this time: less noise = less stress.

Our noisiness is making all whales a bit lonelier (and a bit more stressed).

Fortunately, noise is one of the easiest pollutants to fix. Engines and propellers are getting quieter, and shipping slowdown areas where there are whales have reduced the acoustic intensity by 70%. We could see an Ocean far less impacted by our noise in the near future.

How has whale song connected us to the Ocean?

The discovery of whale song connected us to these Ocean giants like never before. The Songs of the Humpback Whale helped launch the Save the Whales campaign, ending industrial whaling.

52 has prompted songs, such as 52 Whalien by K-pop band BTS, tattoos, sculptures and stories. Wherever the story goes, there is an outpouring of sympathy and empathy. So many have found empathy, understanding and connection with 52.

The more we have listened to our Ocean, the more we have discovered, and the deeper our connection has grown. 52 has been a focal point for the misunderstood and unheard. But, as his popularity has shown, we aren’t as lonely or misunderstood as we may believe – and maybe 52 isn’t either.

Quick questions.

What kind of whale is 52 Hertz?

We don’t know for sure. Scientists have suggested a hybrid of a blue and fin whale, or one of those species with a slightly different morphology.

Where does the 52 Hertz whale live?

The calls of the 52 Hertz whale have been recorded off the west coast of North America, from Alaska to California and further south to Mexico.

Is the 52 Hertz whale alive?

Most likely. We first heard these calls in the 1980s, and whales live a long time. Blue and fin whales can both live over 100 years, and we likely don’t know just how long they can live because industrial whaling lowered the life expectancy of whales considerably.

Is the 52 Hertz whale lonely?

We don’t think so, although loneliness can be difficult to spot. Check in on your friends.

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Will Steen

The oldest things in the Ocean: Explained.

Monthly: Impact in your inbox.

12. 05. 2026 Will Steen

How did fish farts nearly end the world?

How did herring farts nearly end the world?

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Fish don’t even fart. Let’s talk about the time that not knowing about the Ocean, or herring (a fish), nearly kicked off World War 3.

The Cold War was dotted with moments that brought humans closer to annihilation than ever before. Checkpoint Charlie, the Cuban Missile Crisis and various satellite proxy conflicts all presented opportunities for humanity to self-destruct.

1981 was witness to one of the best named incidents – the Whiskey on the rocks incident.

What happened during the Whiskey on the rocks incident?

On 27 October 1981, S-363 – a Whiskey-class submarine from the Soviet Union – ran aground in Swedish waters.

The defence presented by the Russians emerging bashfully from the beached boat was navigation failure. One that had mysteriously taken them through the complex topography (seabed features) and within ten kilometres of one of the most important naval bases in Sweden.

The Swede’s were (understandably) sceptical. Later, the Soviet story changed, claiming the vessel entered Swedish waters due to being in distress.

Increasing the tension, Swedish radiation detectives concluded a high likelihood of the submarine carrying nuclear weaponry – a challenge the Soviets did not deny.

Whether or not they intended to be there, with whatever weaponry, the incident showed Sweden and the world that Soviet submarines were active within Swedish waters. Where there was one, there could be more.

Listening for danger

As a result, the Swedish Navy were on high alert, listening and watching for more intruders. Intruders they kept finding.

Finding submarines isn’t an easy business, especially in the often-murky waters around Sweden. When you can’t rely on your eyes, use your ears. Sound travels four to five times faster (and further) in water than it does through air, due to the increased density of water.

Submarine warfare led to the development of underwater listening technology, using underwater microphones: hydrophones.

A hydrophone is a microphone specially designed to listen to and record sound waves underwater.

Hydrophone being deployed in the Ocean. Posted by Ocean Generation. — Photo by Dave Mellinger/Oregon State University

Over the next decade, there were several high-profile submarine hunts, as hydrophones picked up the sounds of a submarine, which were chased, cornered and showered with depth charges (bombs set to explode at certain depths).

But no hits were recorded, and no traces of the underwater invaders were found. The Russians maintained: there were no submarines.

The fall of the Soviet Union in 1991 saw a global de-escalation in tensions. The Swedes expected a let up in their little hide and seek game.

Yet the Swedish navy continued to chase Russian submarines they could hear in their waters.

By 1994, the Swedish prime minister had enough and sent the President of Russia, Boris Yeltsin, a complaint, asking him to reign in his navy. Yeltsin maintained that there were no Russian submarines entering Swedish waters.

The Swedes began to question – what if the Russians were telling the truth?

How were the Swedes detecting submarines the Russians swore weren’t there?

The listening stations in Sweden had two sounds that signalled the presence of a Soviet submarine:

kavitationsljud or “cavitation noise”, produced by a propeller ripping up the water, making air bubbles that pop as they collapse;
typljudet, or “typical sound”. The typical sound was a crackling sound, likened to that of frying bacon, thought to be produced mechanically.

If either of those noises were heard, it was labelled a sure-fire incursion. The producer of the noises, however, was no nuclear submarine.

The Discovery: Fish farts that nearly caused WW3

In July 1994, another Russian sub was detected by a sonobuoy – specifically, the cavitation noise was heard.

A sonobuoy is a small floating device that has a radio transmitter above water and a hydrophone array below, able to listen and transmit what it hears.

Sonobouy
being deployed. Posted by Ocean Generation, leaders in Ocean education. — *Photo by sonobuoydude*

This time, another vessel was in the area to investigate immediately.

What did they find? A small, otter-like animal called a mink was observed swimming near the sonobuoy. The cavitation noise had not been the four-bladed propellers of Russian submarines, but the four legs of exploring mustelids swimming between isles of the Swedish archipelago.

Mink is a semi-aquatic animal. Posted by Ocean Generation.

Following this, in 1996, the military invited some bio acousticians (experts that listen to nature) to analyse the typical sound.

Magnus Wahlberg and Håkan Westerberg were the academics brought in, the first civilian ears to hear the sound that had haunted the Swedish Navy for fifteen years.

The noise coupled with reports of bubbles seen at the surface when the typical sound was heard gave the scientists an idea. To test it, they went to the local fishmonger.

They bought a herring, a small, schooling fish. The herring was immersed in a bowl of water alongside a hydrophone and squeezed.

From the rear end of Sweden’s national fish came nothing other than the typical sound.

The Swedish Navy had been depth charging some chattering fish: Clupea (see below).

What are herring?

Herring (Clupea harengus) are among the most abundant fish in the world. Their name may be sourced from the Old German heri meaning “host, multitude”, reflecting their habit of gathering in vast shoals.

Herring reach up to 45cm long and can live for up to 25 years. They typically stick to coastal waters up to 200m deep. The fifth most-caught fish by weight globally, herring have been an important source of food for humans for a long time.

Interestingly, herring have a very good sense of hearing. Initial theories were that this could help them avoid cetacean predators such as orca and dolphin who use echolocation to hunt.

How do herring make noises like a submarine?

In 2004, researchers set out to find out more about the herring and the noise from their rear end. They captured some wild Pacific and Atlantic herring and recorded them using hydrophones.

The scientists recorded and categorised the typical sound: bursts of 7-65 pulses lasting between 0.6 and 7.6 seconds, with frequencies ranging from 1.7Hz to 22kHZ. This herring harmony was named: Fast Repetitive Ticks, or FRTs for short. Who says scientists have no sense of humour?

To investigate the reasons for the noise, they ran several scenarios. Some fish were being fed and some deprived food. There was no change to the number of FRTs between the groups.

Herring is a small schooling fish. Posted by Ocean Generation, leaders in Ocean education. — *Photo by Hunter Stevens*

So: these noises are not “farts” at all.

Listen to the noisy herring here.

Researchers then blacked some of the fish from access to the surface, to see if the FRTs were from gulped air being pushed through.

On the first night, there was no significant change, however when the trials progressed for a second and third night, FRT production dropped significantly. It seemed the herring did need air access eventually to ‘recharge’ their FRT tanks.

The tanks themselves were surprising. The researchers concluded that the FRTs were produced through expelling air from their swim bladder out of their anus: “a form of sound production not… previously described in fishes.”

Why do herring ‘fart’?

Not a by-product of digestion, so why would some small fish squeeze air out of their swim bladder?

Buoyancy regulation was suggested, as the swim bladder is predominantly used to adjust how ‘floaty’ a fish is – more air will mean it floats closer to the surface. However, fish kept in shallow tanks had no need to alter their buoyancy yet were merrily FRT-ing. It wasn’t buoyancy either.

Herring have long been known for their exceptional hearing. Maybe, then, they produced this noise for each other’s benefit? The fish were not in breeding condition, so they knew it wasn’t a mating function. Researchers separated them into tanks with different numbers, from 1 to 30. The number of FRTs each fish produced increased when they were around more herring, implying that there was a social function.

They dug even deeper. They found FRTs were mostly produced at night (specifically between 23:00 and 00:00). Was it a stress signal? The herring produced no FRTs during tank maintenance, but to make sure they took it a step further.

The researchers took water from another tank, one that contained a “high density” of spiny dogfish (Squalus acanthias) and added it to the herring tanks, filling them with sharky smell. It did not draw even a startled squeak.

Off this evidence, the researchers suggested that FRTs are not a stress or mating response, but purely for social contact – particularly maintaining cohesion in darkness.

Anatomy of a herring, edited for clarity by Ocean Generation. — *Klink-hard (1996) via Wahlberg and Westerberg (2003).*

In many ways we are lucky that it was the Swedes combating these ephemeral Russian submarines. This peaceable country hasn’t fought a war since 1814 and has never had nuclear weapons (although had a programme exploring the possibility until 1968). A more hot-headed geopolitical player could have taken things more personally and escalated beyond a strongly worded letter. Fish “farts” really could have ended the world, and we never would have worked out they aren’t even farts.

Thankfully, Sweden put curiosity first and went from a stranded submarine to bubbling butts to a deeper understanding of communication and social structure in the humble herring. Who knows what more listening in the Ocean could reveal?

Cover image by Henry Zbyszynski

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Will Steen

The oldest things in the Ocean: Explained.

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15. 04. 2026 Will Steen

Fact file: Fun facts about orca (killer whales)

Orca fact file, posted by Ocean Generation.

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Orca (also known as killer whales) are famous residents of the Ocean. They are fast, fashionable and family-oriented. Frankly, they are fantastic.

Are orcas whales or dolphins?

Orca aren’t whales, they’re dolphins.

The commonly used name, killer whales, can cause confusion. Early sailors became familiar with orca hunting the great whales, naming them “whale killers”. Somewhere in history, that got flipped to become “killer whale”, even though orca are actually dolphins. They are the biggest of the dolphins.

Are all dolphins whales?

Technically, the whole dolphin family, the Delphinoidea, belong to toothed whales – the Odontoceti. Along with the Mysticeti (baleen whales) they make up the cetaceans.

So, you could argue all dolphins (and therefore orca) are in fact whales but they have dolphin-specific traits so, they’re not ‘true whales.’

Orcinus orca is currently a single species, although scientists have suggested dividing it into races, sub species or even different species.

Different groups of orcas are known as ecotypes which inhabit different parts of the Ocean and show physical and cultural differences. They speak different dialects, eat different food and grow to different sizes with different colouration. In many ways they are much like humans.

Order cetaceans explained by Ocean Generation.

Where do orca live?

Populations can be found all over the world, typically preferring coastal seas to the open Ocean, and the higher latitudes closer to the poles. The main population centres for orca are in the Southern Ocean, the north-eastern Atlantic and in the northern Pacific, but orca can be found from Hawaii to the Arctic.

How many orcas are there?

There is an estimated global population of 50,000 orca, including 25,000 in the Southern Ocean, and 10,000 in the waters of Norway, Iceland and the Faroes.

The global population of orca has not been assessed by the International Union for Conservation of Nature (IUCN). We don’t know enough to say whether orca populations are increasing, decreasing or stable.

We do know about the different orca sub populations around the world. Some, such as the Iberian orca population which has been sinking boats, are critically endangered. The West Coast Community of the UK is thought to only have two members remaining: Aquarius and John Coe, who at over 60 years old may well be the oldest male killer whale in the world.

Other orca populations are doing better. Antarctic populations are hard to study, but thought to be stable. Northern Resident orca of the west coast of North America are listed as threatened, but their numbers are increasing by an average of 2% per year after protective measures were introduced for them and their main prey – harbour seals.

Where do orca live: explained by Ocean Generation. — *Image by NOAA*

What do orca eat?

All orca are carnivores but different populations of orca have different preferred diets. Norwegian orca have specialised in herring, northeast Pacific orca hunt salmon and New Zealand orca focus on elasmobranch species such as eagle rays, stingrays and shark species.

Two orca brothers in South African waters, Port and Starboard, are infamous for targeting great white sharks, flipping them onto their backs into a trance-like state known as tonic immobility and eating their livers. As a result, great whites leave the area when orcas are about. Other orcas have been recording other shark species such as whale sharks, seven gill sharks, mako sharks and white sharks.

Nothing is off the menu. Orca will hunt marine mammals, including walrus, dolphins, narwhals, beluga and whales. Orca have been recorded recently hunting the largest animal that has even lived: blue whales.

Being out of the water doesn’t always help. A population in Patagonia will beach themselves to catch the young sea lions learning to swim in the shallows. A population in Antarctica has perfected a technique of swimming together to create waves to break up ice and wash any seals taking refuge on it into the water.

Their most surprising prey? Orca are one of the main predators of moose, who swim between islands and even dive down to eat aquatic foliage.

Nothing is off the menu, apart from humans – no human has ever been killed by a wild orca.

Orcas are also known as killer whales. Posted by Ocean Generation, leaders in Ocean literacy

Killer Facts about Orcas

Orca have been recorded reaching 9.75m in males, and 8.53m in females. The Antarctic Type A ecotype are the largest of all the orcas.
A population off the western coast of North America has revived a fashion fad last seen in the 1980s of swimming around with dead salmon on their heads. Fashion experts compare this to the revival of the bucket hat.
Orca are among the very few species to go through menopause in the wild. Beluga, narwhals, short-finned pilot whales and false killer whales join humans in this exclusive group. This allows orca grandmothers to act as vital sources of knowledge in food location and hunting techniques, while avoiding them competing reproductively with their daughters.
Orca are estimated to eat nearly 800kg a week (roughly 1600 loaves of bread or 8,000 apples).
Orcas only fear one animal – the long-finned pilot whale. They have been observed fleeing at high speed when pilot whales arrive. We don’t know why.
Orca have been known to look after disabled members of the pod.

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Will Steen

The oldest things in the Ocean: Explained.

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1. 04. 2026 Will Steen

Who are the orca outlaws sinking boats, and why are they?

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Why are orca sinking boats?

Revenge, anti-capitalist revolution, competition, territoriality, a ‘tide-pod’ challenge-esque fad, curiosity – all suggestions to answer one question: why are orca sinking boats?

Much changed in the world in 2020. We all stayed home, made banana bread and, in the UK, attended Joe Wicks workout classes. There was a change in the Ocean in 2020 too: orca began bumping boats.

Now, almost six years on, 8 boats have sunk and over 250 have been damaged. Looking at the data from these interactions, and through knowing these orca, can we piece together why they might have started down this road of vessel vandalism?

What are orca?

Orca (Orcinus orca) are the apex marine predator. Orcas are the largest of all the dolphins (despite their killer whale nickname, they aren’t true whales; read our orca fact file here).

They are found throughout the Ocean, from Antarctica to Norway, Argentina to New Zealand to South Africa.

Orca are highly social and highly intelligent, living in large family groups usually led by a matriarch – an older female. They are capable of advanced communication and coordination, executing intricate, risky and ingenious hunting strategies. Orca are incredible.

They have been recorded hunting whale sharks, white sharks, walrus, and whales (hence their nickname, killer whales). Scientists don’t believe they are particularly affronted by species beginning with W.

When orca hunt, they can create waves to wash seals off ice (or smash the ice they are on) and intentionally strand themselves on beaches to catch sea lions in the shallows. Orca also upend white sharks to paralyse them in tonic immobility (a trance-like paralysis some sharks enter when upside down).

Orcas live in close-knit family groups. Explained by Ocean Generation.

Who are the orca that sink boats?

The Iberian orcas are a small population of orca that reside in the western Atlantic from Gibraltar up to the Bay of Biscay. The ‘small’ is a double entendre. They are among the smallest orca on the planet, with females reaching up to a mere 5.8m and males only 6.5m. They are also small in number: the International Union for Conservation of Nature (IUCN) classify this population as critically endangered, with the population estimated to number only up to 50.

Between 1999 and 2011, 47 individuals from 5 different pods were photo-identified and a further 16 in the Canary Islands, which are genetically distinct (they aren’t family) from the Iberian orca. After accounting for deaths, the Iberian population was 33 in 2012.

In 2023, the number had grown to a relatively stable 37.

Of this orca population, 15 individuals have been identified as boat-bumpers from witness accounts, photos and videos. These sailing saboteurs are then given the moniker “Gladis” – derived from gladiator, or fighter.

The Gladises are in two main pods, each led by an older matriarch. Gladis Lamari is estimated to have been born in 1992 and Gladis Herbille in 1993. Neither of them have directly interacted with boats: they are Gladises as they have been observed close by during boat interactions. They seem content to sit back and watch the younger ones.

What do the Iberian orca eat?

From April to June, the Iberian orcas gather in the shallower waters of the Gulf of Cadiz and the northwestern strait of Gibraltar. Why? Because it is the start of the spawning migration into the Mediterranean of their primary food source: Atlantic bluefin tuna.

In July the orcas shift to the central Strait of Gibraltar as the tuna begin to return to the Atlantic and follow them up the coast of Portugal into September and October.

Iberian orcas feed on Atlantic bluefin tuna. Explained by Ocean Generation.

How do we know the orcas are eating tuna?

By using crossbows, mass spectrometers and following the principle “you are what you eat”. A skin sample was collected from biopsy darts, fired from a modernised version of the ancient weapon. To reiterate: a marine biologist, armed with a crossbow, gets a bit of skin and can work out what the orca are eating.

To assess the diet, the orca skin is analysed for the ratios of carbon and nitrogen isotopes.

Isotopes are atoms of the same element with different masses, due to different numbers of neutrons.

Carbon isotopes indicate where an animal feeds, while nitrogen indicates the trophic level (higher trophic level means higher up the food chain – a predator that eats predators, like orca, have a high trophic level).

In short, the fish an animal eats leave different ‘signatures’ that we can read, telling us what and where our orca are eating.

The Iberian orca showed carbon and nitrogen values reflecting a diet of Atlantic bluefin tuna, with one exception. The female (named Vega) had higher ratios of heavier carbon, showing she was eating more coastal fish species – everyone has their preferences.

Have orca previously sunk boats?

The history between the Iberian orca and humans is a long one. The great Roman author Pliny the Elder reported the presence of orca in AD77. The catch of local fishers was said to increase when the orca were around, and even that fishers would wait for the killer whales to herd the tuna towards shore to help them.

More recently, the tables have turned. Now it is the orca using the fishers for an easier meal, taking tuna caught on fishing lines as they are hauled in. Unfortunately, this is a dangerous strategy, and orca have been seen with deep wounds and amputations, likely from interacting with fisheries.

But before 2020, we have very few instances of orca sinking boats.

In 1820, a whaling vessel, the Essex, was sunk by a sperm whale in the Pacific. In the aftermath, the crew reported orca attempting to sink one of the small boats they had escaped the Essex in.

There were two boat sinkings in the 1970s attributed to orca: in 1972 a 43 ft sailing boat in the Pacific, near the Galapagos, was sunk by a pod of orca. In 1976 another sunk off the coast of Brazil. A juvenile male orca, L98 or Luna, had a long running period of interacting with human things from 2001-2006.

Luna was separated from his pod when he was just 2 years old. He spent five years around Vancouver Island where he would interact with floatplanes and boats, causing damage to the craft and occasionally hurting himself. Sadly, Luna was killed in March 2006 by a tugboat.

How many boats have orca sunk?

Some social media posts have claimed over 1,000 boats, but as of March 2026, 8 vessels have been sunk.

Where have orcas been sinking boats? Explained by Ocean Generation. — *Map via Google Earth*

31 July 2022 – unnamed sailing vessel sinks offshore from Sines, Portugal
1 November 2022 – The Smousse, a 39ft sailing yacht, sunk off Viana do Castelo, Portugal
4 May 2023 – Alboran Champagne, 50ft sailing yacht, sunk off Gibraltar
31 October 2023 – Grazie Mamma, a 46ft sailing yacht, sinks in Strait of Gibraltar
12 May 2024 – Alboran Cognac, a 49ft sailing yacht, sinks in Strait of Gibraltar. From the same charter company as Champagne
26 July 2024 – Bonhomie William, a 39ft sailing yacht, sinks in the Strait of Gibraltar
13 Sept 2025 – Oceanview a 36ft sailing yacht, sinks off Fonte da Talha
10 October 2025 – Ti’fare, a 36ft sailing yacht, sunk off Peniche, Portugal

It is important to underline, everyone sailing on these boats was rescued safely. There have been no injuries or deaths from the orcas, or aggression shown towards humans.

How many boats have orcas interacted with?

Using the last published data from November 2025, there have been 761 interactions between the Gladises (the nickname for orca seen around boats) and boats around the Iberian Peninsula.

The numbers recorded are from the Cruising Association, a sailing group that have encouraged reporting of incidents, which they verify in their network. These numbers are an underestimate, as not every interaction is reported, especially minor ones.

25 May 2020 – the first interaction between two unidentified orcas and a rigid-hulled inflatable boat in the Strait of Gibraltar, no damage recorded.

20 July 2020 – first recorded ‘disruptive’ interaction. Following 9 days saw five more incidents, all south of the cape of Trafalgar, just north of the strait of Gibraltar.

July–November 2020 – 52 interactions, 49 confirmed physical contact. 9 Gladises by the end of the year.

2021 – 146 interactions, number of Gladises rises to 14.

2022 – 138 interactions, 2 sinkings. Number of Gladises rises to 15.

2023 – 186 interactions, 2 sinkings.

2024 – 125 interactions. 2 sinkings.

2025 – 134 interactions up to 10 December. 2 sinkings.

What boats are orcas bumping?

The average length of vessel is 12m, or 39ft. Around 80% of the vessels involved are sailing boats. Of those sailing boats, most have a particular type of rudder– a spade rudder.

What are the theories for orca interacting with boats?

Are orca out for revenge?

A commonly given reason for why orca are sinking boats is that of revenge. The narrative is compelling: an orca, injured by a passing boat, calling her kin to arms to meet the threat of humanity. A response from a beleaguered and besieged marine world.

This theory has largely come about because of an orca named White Gladis.

Who is White Gladis (Blanca)?

White Gladis, translates from her Spanish name, Gladis Blanca. Born in 2005, Blanca is the mother of Gladis Filabres, Gladis Dalila and Gladis Clara. She is herself the daughter of Gladis Lamari, who has been present during interactions but never actively touched a vessel.

As a reminder: Gladis is a simple designation given to any orca involved in nefarious nautical activity. It has its origins in an early name for orca – Orcinus gladiator, meaning whale fighter – and the term gladis means fighter.

The theory is that Blanca had the marks of a propeller and was teaching her kin to destroy the thing that hurt her.

Is White Gladis (Blanca) looking for revenge?

Blanca was certainly one of the early proponents of this behaviour. The first interactions in July 2020 were Blanca, her half-sister Gladis Dalila and an orca from another pod, Gladis Negra.

Orca mothers and grandmothers are key figures in orca society – they are one of the few animals other than humans that are known to go through menopause in the wild, as the grandmothers act as a font of knowledge that they can pass on to the younger generations.

She also does have scars on her skin. But she is an old orca, from a pod known to interact with fishing boats.

Who is White Gladis, also known as Blanca?

Some of those markings are likely to be tooth raking marks, from other orcas running their teeth down her side in play or in mating. Others may be from fishing lines – these orca are known to steal tuna from fishermen, they could well end up with scars from hooks or lines getting tangled.

None of the marks are likely from a propeller – a sticking point for a theory that relies on a negative interaction with a boat.

Is she out for revenge? Orcas are capable of hunting the largest animal to have ever lived (the blue whale) and snacking on the liver of one of the most notorious Ocean predators (the great white shark). They are 5m muscular torpedoes that can develop sophisticated hunting strategies.

If these ‘wolves of the sea’ wanted to wreak havoc upon the sailing community, they could. Only 8 sinkings over 5 and a half years suggests that isn’t the intended outcome.

Are orcas feeling the pressure from humans?

Related to the idea of revenge is the theory of competition between orca and humans. Tuna are the main food of this population and a prized fish for human consumption. Tuna stocks were crashed in the mid 2000s by overfishing, leading to zero Iberian orca calves surviving between 2006-2010.

Orca have been seen with fishing lines attached to them, and one individual in the population, Corsica, suffered a severed right flipper and a cut at the base of her dorsal fin. Corsica was not a Gladis, and although her daughters are given Gladis designation, they have only followed small boats, not sailing boats, and never damaged any. Corsica was sadly found dead in March 2022.

The Straits of Gibraltar is one of the busiest areas of Ocean for marine traffic and has high noise and chemical pollution levels.

The theory is that the ongoing pressures from noisy neighbours that are taking the orcas food is leading them to vent frustration on an easy target – sailing boats. Hard to prove, and the orca with the clearest motivation to do so (Corsica and her relatives) never showed this behaviour.

Are orca using boats as hunting practice?

The behaviour of these orca – ramming and targeting the stern of the boats – is comparable to the hunting strategies they employ when targeting the blue-fin tuna this population eat.

Arguments have been made that the orcas are using sailing vessels as a hunting tool, a training target to show younger orca how to hunt. The incidents started with older females and were followed by younger individuals copying.

The leading theory for our ship shakers? That they want to play.

As previously mentioned, part of the evidence for this is how few boats have sunk – it doesn’t seem to be the intended outcome.

The boats receiving orca attention are interesting. They are mostly sailing boats with spade rudders – these rudders turn completely, as opposed to overshot or hinge rudders, which have a ‘backbone’ of rudder that doesn’t. The boats getting bothered are those with the most mobile pieces on them. Sailing boats typically travel between 5 and 9 knots, a comfortable speed for an orca.

You have slow-moving vessels moving through the orcas home, and they all have a moving thing at the back – pretty enticing for some bored young orca.

The leading theory of why orcas sink boats is play.

The missing orca generation.

The lack of calves between 2006 and 2010 could be in play in a different way here. There is a missing generation of orca: young orca are missing older calves to play with. As any bored child will start doing, they make up some games for themselves, using what is available (boats).

How do you avoid getting sunk by a pod of orca?

The best solution: don’t sail a spade-ruddered monohull sailing vessel around 12m long between Gibraltar and Galicia from July to October.

But seriously: guidance for sailors is unfortunately varied. Initial studies suggested that boats are slightly more likely to be damaged if they keep moving – if boats stop, the orca can lose interest and move off.

More recently, Portuguese authorities maintain that playing dead or reversing is the best way, while Spanish authorities advise motoring to more shallow water.

The International Whaling Commission held a workshop attended by orca experts from around the world. The guidance was to move at least 2-3km from the area of first encounter to an area where rescue, if needed, is easier.

The same workshop strongly recommended against using deterrents that could harm the orcas. Besides the fact this is a critically endangered population, none have been shown to succeed in stopping an interaction and they are likely more dangerous to the people deploying them.

Desperate sailors have used some extreme counter measures to protect their floating homes. Throwing firecrackers and seal bombs; pouring bleach, diesel or chlorine overboard; attaching knives or spikes to the rudder; throwing rocks or heavy chain; electrocution.

It is difficult to condemn sailors reaching for anything they have to hand when a six-tonne animal is apparently dismantling their boat from underneath them. But these measures range from ineffective to cruel, and present as much risk to the sailors as the orca, if not more.

Rather than bombs and chemicals, are there any other potential solutions?

A few genuinely promising suggestions have been put forward. Modifying the design of the rudders to alter the flow of the water could make them less appealing to orcas in the first place. Dropping a barrier of weighted lines around the stern of the boat to prevent easy access to the rudders could give sailors some more peace of mind.

Orca have been shown to flee when they hear the calls of long-finned pilot whales. Sailors could either play pilot whale calls via underwater speakers, learn to mimic these calls or bribe local pilot whales for protection (we would love to see some pilot whale language classes).

Our changing relationship with orcas

Whatever the reasons and whatever the solutions, the situation does give us a chance to appreciate the intelligence and power of one of the Ocean’s top residents.

Our relationship with the orcas of Iberia has been tumultuous. Pliny the Elder wrote about them in AD77, while the birth of Jesus was in living memory. Medieval fishers would welcome them as partners, watching for their dorsal fins to show the tuna were running. More recently, the relationship soured – in 2002, an orca, Burela, was found dead with bullet wounds.

Now it is more confused than ever. The waters are shared by sailors armed with firecrackers, dreading that a black fin will approach from behind, and by whale-watching boats filled with passengers with crossed fingers that they may see the exact same thing.

At the centre of it all, is curiosity. The same thing powering the whale-watching companies could be compelling the orcas. Revenge becomes something more ordinary and wonderful. Just as a younger sibling might poke a sandcastle on a beach and accidentally knock your tower down, the orca could be exploring and playing, with some unfortunate consequences.

Humans and orca have shared the Iberian waters for millennia. We have been wary strangers, reluctant neighbours, collaborative hunters and fierce rivals. How we react to this next chapter in our relationship with them will reflect on us more than it does on them.

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Will Steen

The oldest things in the Ocean: Explained.

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31. 03. 2026 Will Steen

Secret life of algae: From oxygen to algae blooms

Secret life of algae. Posted by Ocean Generation

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Every second breath we take comes from the Ocean. More specifically, it comes from algae in the Ocean (thank you, algae).

When the conditions are right, algae flourishes, creating an algal bloom. These blooms can be spectacular, leading to a blossoming of life and a sparkling Ocean, or they can cause serious problems for life in the Ocean and on land.

What do the white cliffs of Dover, the oil fields in the North Sea and Colorado oil shales and the clarifying agents used to make beer and wine have in common? They are all made of algae, a diverse group of incredible organisms which support most of the life in the Ocean.

But you can have too much of a good thing.Large amounts of algae can kill a lot of marine life and be toxic to humans. These events can have huge impacts, as we will see, from modern day Australia to the Bible.

What are algae?

This isn’t as simple an answer as it should be, so bear with us. Unlike mammals or birds or sharks (don’t get us started on “fish”), “algae” doesn’t refer to a single evolutionary group of species.

Instead, the things we call algae are a group of organisms that do the same kind of things, dotted around the tree of life. A group of roughly 50,000 species.

The name comes from the Latin for “seaweed”. The study of algae is called phycology, and algal experts are phycologists, who are still figuring out exactly how they all fit together.

As a good rule of thumb – if it photosynthesises, and it isn’t a land plant, it is algae (we will get to the differences between algae and plants in a minute).

Some of those 50,000 species are very basic organisms such as cyanobacteria, that lack a nucleus and the other advanced bits of cellular equipment that animals have.

Other species are single-celled, floating around in the Ocean. Some are macroalgae like kelp, growing over 50m tall, creating vast forests filled with life and noise (ever wondered what the kelp forest sounds like?).

The magic of algae is something they share with plants. They produce oxygen and grow using sunlight – photosynthesis.

This magic is what nearly all life on our planet is dependent on.

How are algae different from plants?

Fuelled by the sun’s energy, algae filled the Ocean and some conquered the land, becoming the plants that dominate our planet.

Plants evolved from ancient freshwater algae over 440 million years ago. Trees appeared around 400 million years ago. Psst…for context, sharks first appeared around 450 million years ago, so sharks have been around for longer than trees. 1-0 to the sharks.

Plants have developed into some beautiful, complex forms, conquering the land and making up around 82.5% of total biomass (the weight of living things) – humans are only about 0.01%.

Meanwhile, algae have evolved to master the aquatic world.

Physical differences between algae and plants

Plants developed a number of structures as they conquered the land, with roots to hold them in place and specialised structures for capturing sunlight – leaves.

Looking at seaweed there are clear similarities. The “roots” of seaweed are holdfasts, the “stem” is a stipe, and the “leaves” are blades. They look similar, but these structures don’t transport nutrients or gases between each other as the plant equivalents do.

Microscopic algae lack these structures completely.

Differences between plant and algae. Explained by Ocean Generation.

What are the biochemical differences between algae and plants?

We won’t get too technical, but there are some big differences in the biochemistry of the two. Algae are much more varied in their structures, using a wider variety of building materials. Some use silica (glass) and some create chalk. Green algae use a compound called cellulose – the sugar that makes up paper, cotton t-shirts and wood.

Plants, evolving from these algae, adapted cellulose into compounds such as lignin for structural support in their ongoing battle against gravity.

Many algae are named after their eclectic use of photosynthetic pigments.

Red algae use phycoerythrin and phycocyanin (which appear red), brown algae use fucoxanthin giving them a golden-brown colour and green algae use the same chlorophyll a and b as their green, leafy land-based relatives.

The different pigments are utilised to ensure that the algae are most efficiently gathering the sun’s light, which is filtered by the water, modifying the wavelength (and therefore colour) of light that most gets through. More on that another time.

Types of macroalgae, explained by Ocean Generation.

Where can you find algae?

You can find algae everywhere, and each habitat has its own name. They can be found in ice (cryophilic) and hot springs (thermophilic).

Algae are also in soil (edaphic) and in the Ocean (planktonic in the water column and neustonic on the surface). On rocks and in coral (epilithic and endolithic), on fungus and other plants (epiphytic), on turtles and sloths (epizoic) and even inside other organisms (endozoic endosymbiotic) – there is an alga for any location.

Someone should make a song about it.

Why do algae bloom?

When algae grow very fast into large numbers, it’s referred to as a bloom. This can happen at small scales in a pond or at huge scales visible from space. These blooms can be the start of a great flourishing of life, or a deadly threat.

To understand why algae might bloom we need to realise why it wouldn’t and identify what is limiting its growth. Both plants and algae growth are limited by several things: water, temperature, light and nutrients.

We are focusing in on the marine, where water is less of a concern, so short term variation is typically controlled by the rest (although how salty the water is does matter).

Different algal species will have different preferred conditions, but warming the Ocean, with more sunlight and more nutrients, would generally result in more algae.

To refine it further, algal blooms typically refer to large amounts of microscopic algae, kelp forest is technically an algal bloom too, but in headlines, ‘algal bloom’ usually means the small stuff that can produce massive blooms.

Increasing light and temperature

Algal blooms are a normal part of the seasonal Ocean, as light and temperature increase in spring and summer, they allow algae to grow. This growth, like the arrival of spring on land, can be spectacular, as the sea sparkles with bioluminescent algae such as Noctiluca sp. which can give off a blue glow.

What happens in spring that might cause this? The days get longer and the temperature rises. More light and higher temperatures encourage algae to bloom, and they will until one of the other conditions becomes the limit.

Why do algae bloom? Explained by Ocean Generation, leaders in Ocean education

Increased nutrients

When light and temperature are in plentiful supply in the summer months, the growth of marine algae is limited by nutrient levels, especially nitrogen (as opposed to freshwater, where it is phosphorus).

Human activities, primarily the use of fertiliser in agriculture, which is rich in nitrates, have altered the cycling of nitrogen. Some areas of Ocean receive much higher levels of nitrogen from water running off farms, giving the algae all the ingredients they need to thrive and bloom.

Lowered salinity

A lower level of salinity (saltiness in the water) means a higher concentration of water, enabling more growth. An increase in rainfall or ice melting could then lead to an algal bloom.

What makes an algae bloom harmful?

Broadly speaking there are two ways algal blooms can make life a bit rubbish for everything around it – by choking or poisoning them.

Choking blooms

When a large bloom of algae happens, it can disrupt the balance of the ecosystem.

But the real dangers come in the aftermath. As the bloom subsides, it is decomposed by bacteria and other organisms, which use oxygen. This can leave little or no oxygen in the water left for fish and other aquatic residents to breathe.

What makes algal blooms harmful? Posted by Ocean Generation.

Which Bible story might have an algal bloom?

You may not think to go to the Bible for marine science but let us look at the story of Moses and the plagues of Egypt in Exodus 7: 20-21: “…all the waters that were in the river were turned to blood. And the fish that were in the river died; and the river stank, and the Egyptians could not drink the water of the river”. If we assume the bit about blood is descriptive rather than literal, we have a good description of a bloom of red algae.

Following this, we can link some of the other plagues that befell Ancient Egypt. To recap, the ten plagues were: river of blood, frogs, mosquitoes, flies, death of livestock, boils, hail, locusts, darkness and the death of each firstborn son.

If there was an algal bloom that suffocated the Nile, killing many of the fish, then the things the fish ate would benefit, if they could survive low oxygen conditions. Something like a tadpole, which can respond physiologically to low oxygen conditions and thrive. With no fish, you could end up with a lot of tadpoles surviving, and… a plague of frogs.

Another winner would be mosquitos – they lay their eggs on water surface, and the larvae feed on algae. With less predators (the fish are dead) to eat them and a banquet of food, you get a plague of mosquitos.

The death of much of the life of the river could poison the waters, resulting in the deaths of many of the livestock which depend on those waters to drink. The decay attracts flies, meaning one big algae bloom could be exactly the tool a deity would wield to cause five plagues.

Another algal alternative is that the red “blood” came as a result of heavy rainfall in the Ethiopian mountains that are the source of the Nile. The soil there is clay – reddish in colour – and could have suffocated the river by reducing how clear the water is (its turbidity), meaning the opposite of our theory – there were very few algae to produce oxygen for the fish.

In either case, the algae hold the key to the ecosystem, and impacts to algae can have biblical effects.

Toxic blooms

There are three main types of phytoplankton that can make harmful toxic blooms: diatoms, dinoflagellates and cyanobacteria. These produce toxins themselves. When their abundances reach high enough levels, they become toxic to species in the water, and to humans – directly and indirectly.

Shellfish poisoning in the US is caused by algae such as Alexandrium catenella or Karenia brevis (both dinoflagellates) which, when ingested by shellfish such as mussels, can make them deadly to humans.

Shellfish poisoning explained by Ocean Generation.

More directly, blooms of toxic algae threaten life through the water column. K. brevis is amongst the best studied, as it occurs off the coast of the United States in “red tides”. Fish, marine mammals, elasmobranchs, turtles, birds and even coral suffer in waters stocked with high quantities of the toxic algae. K. brevis produces brevetoxin, potent neurotoxins which interfere with normal neural function. It essentially causes nerves to continuously fire, leading to behavioural change, muscular dysfunction and disorientation.

Blue-green algae are another commonly referred to algal bloom. It is named after the colour of the cyanobacteria that causes it, which can produce a wide array of toxins depending on species, none of which are good in high quantities.

Australia saw a harmful algal bloom start in March 2025

In March 2025, South Australia began to feel the effects of a huge algal bloom. As of February 2026, the bloom has impacted 20,000 square kilometres and roughly 30% of Australia’s coastline. Over a million marine animals have died, from over 550 different species. Humans have suffered from eye and skin irritation, coughing and shortness of breath.

The finger was initially pointed at Karenia mikimotoi, a well-known species that often blooms around the world. But after brevetoxins were identified, which K. mikimotoi doesn’t make, researchers took another look using DNA sequencing. This identified K. cristata, which had only been previously found in Newfoundland, Canada in 2014 and in South Africa in 1988.

This is one of the largest and longest harmful blooms recorded, affecting a huge range of marine animals. Leafy sea dragons are one of the state symbols for Southern Australia, but the bloom has hit their populations hard enough that their populations are being reassessed for risk of extinction.

When does an algal bloom become deadly?

The simple answer is when there is too much.

Too much of any one species results in imbalance. Harmful algae blooms come when the balance is lost, for example with an excess of nutrients or an Ocean that is much warmer than usual. Pollution and climate change are increasing the frequency of harmful algal blooms. Not every algal bloom is caused by human activity, but more of them are, and they are more likely to be harmful. Tackling climate change and pollution protect animals like the leafy sea dragon.

Algae facilitated life on our planet, filling the atmosphere with oxygen. Still today, every second breath you take comes from the Ocean, specifically the little algal friends at work. They continue to be the foundation of marine food chains. Algae are amazing; you just don’t want too much.

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The oldest things in the Ocean: Explained.

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20. 02. 2026 Will Steen

What is Ocean circulation – and why does it matter?

What is Ocean circulation, and why does it mater? Explained by Ocean Generation

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The Ocean is in constant motion.

Why does Ocean water move? Think about it. What do you need to move the Ocean? What is Ocean circulation, and why does it matter?

There are three drivers of Ocean currents.

The most visible driver of Ocean circulation is the wind. Big storms can whip up the waves, send them crashing into the rocks or barrelling over surfers. Waves can seem like the Ocean is moving a lot, but the water itself is moving mostly in a circular motion. We explain more in our article on the motion of the Ocean.

Prevailing winds can push the waters below in a consistent direction, such as the Gulf Stream, which does drive larger scale circulation. But usually, the wind is only moving the surface, and the Ocean is a lot deeper than the surface.

Next comes the tides. The moon, with a little help from the Sun, shifts the Ocean back and forth, changing sea level by metres in some places. The Bay of Fundy in Canada has the largest tidal range in the world, with almost 12m difference between high and low tide.

However, the tides are always changing. If tides were the only thing responsible for moving the water, then the same water would just be moved in and out. Out in the middle of the Ocean, the water would travel in a big vertical circle, like a giant Ferris wheel. To move the Ocean properly, we need something else.

The third driver of global Oceanic currents is more understated than crashing waves or retreating seas. It takes thousands of years to move water through the deep Ocean, from pole to equator to pole. It’s known as the Ocean Conveyor, or Thermohaline Circulation, and the polar Ocean is a focal point for its activity.

What moves the Ocean? Tides, wind and the thermohaline circulation explained.

Why is Ocean circulation important?

This movement of water is the heartbeat of the Ocean. It carries oxygen-rich waters to the depths, and where it returns to the surface (known as upwelling), the nutrients it brings with it create the richest waters on the planet.

The Ocean is also moving heat and carbon dioxide. It has absorbed approximately 25% of carbon dioxide emissions since the 1960s and over 90% of the excess heat trapped by greenhouse gases has been assimilated into our Ocean.

The Ocean can circulate and ‘drop off’ heat and carbon dioxide in the deep. If the circulation of the Ocean slows, the surface Ocean will get hotter and more acidic. With less circulation, the Ocean’s ability to trap and store two major drivers of climate change suffers.

Global Ocean Conveyor Belt — *IPCC via Smithsonian*

What is Thermohaline Circulation?

Thermohaline circulation is the slow, powerful pump behind Ocean circulation, the main driver of water movement in the Ocean. The name sounds complicated, but it tells us exactly what we are talking about.

Let’s break it down; Thermo-: we are talking about temperature; -haline about salinity, or saltiness. These two characteristics of seawater influence global climate and biological richness.

Temperature and saltiness have influence because they change how dense Ocean water is. Cold water is more dense than warm water, and salty water is more dense than freshwater. If water is denser, it will sink below less dense water.

These simple differences drive a slow, unseen conveyor belt from the poles to the equator and back again. It would take over 1,000 years for one drop of water to complete the whole Ocean circulation.

What will the cold, salty water now disappearing into the depths in the North Atlantic see when it re-surfaces in the Pacific in 3026?

Thermohaline circulation, explained by Ocean Generation.

Why are the Poles important for Ocean circulation?

If the poles are known for one thing, it is that they are cold. So cold in fact, they can chill seawater to the point of freezing (which happens around –1.8 to -2 degrees C / 28.76- 28.4 °F, lower than normal water due to the salt content).

When seawater freezes, it leaves its salt behind. As ice forms, the water left behind gets more salty, which lowers the temperature it will freeze at. More salt = lower freezing temperature. Very salty, very cold water is very dense, and will sink below other seawater.

This downward movement is known as downwelling. Downwelling pushes water along the depths and pulls water across the surface. This is the pump that moves the Ocean.

So begins the Ocean conveyor.

When does cold water become deadly?

Maybe you didn’t think water movement could be exciting. Maybe you haven’t heard of the finger of death.

We know as sea ice forms, it “spits out” salt, creating channels of brine (very salty water), which is colder than freezing. This brine travels down through channels in the ice, collects more salt and cools further.

It reaches the bottom of the ice super salty and super cold. It is so cold it freezes the sea water it touches below the ice, creating beautiful brinicles.

The brine is still too salty to freeze, so travels through the centre of the brinicle, growing it. If this is in a shallow area, the brine could reach the seabed before warming and diluting enough.

This ethereal beauty then becomes a sinister threat. It is so cold it freezes anything it touches. The sea stars, brittle stars, sea cucumbers living below the ice are at the mercy of the finger of death.

Most Ocean movement isn’t as dramatic as the finger of death, but it runs on the same mechanisms.

Finger of death, also known as brinicle — *BBC Earth*

Is Ocean circulation slowing down?

Ocean circulation relies on the cooling and sinking of water at the poles. As the release of greenhouse gases raises the temperature of our planet, especially at our poles, the water is not getting as cold.

We are seeing less sea ice form and the water has more fresh meltwater diluting it. The water is getting less cold, and less salty. Both mean the surface water is less dense, meaning it will sink less. Is the circulation of the Ocean slowing?

One way to study if it is slowing is by looking at how old the water is – older water means slower circulation.

How do you measure how old water is?

At the surface, chemicals and elements are constantly being exchanged between the air and the Ocean. Scientists can look at the chemical composition of the water, looking for indicators for when the water was last in contact with the surface.

Using Carbon-14 as a time marker

Carbon-14 is the usual way, a radioactive isotope of carbon that is used in radiocarbon dating methods from geology to archaeology. It’s also called carbon dating.

How does carbon dating work?

Carbon-14 is an isotope (type of atom) that decays slowly. Half of it will decay every 5700 years or so, known as the half-life.

Measuring the amounts of Carbon-14 can be like reading a timer. Carbon-14 is created naturally when cosmic rays hit our atmosphere, but in much larger amounts by nuclear weapons – levels doubled in the 1950s and 1960s.

This molecular ‘shadow’ has been found in marine animals in the Mariana Trench, showing just how far human impacts reach.

Track the amount of Carbon-14 and you can approximate when it was last in contact with the atmosphere, which gauges age.

Measuring human-made chemicals

Industrial chemicals such as CFC-12 and sulphur hexafluoride are other chemical clues used to age water. Chlorofluorocarbons (CFCs) were widely used in refrigerants and spray cans until they were identified as depleting the ozone layer.

Through global cooperation and effective science, the Montreal Protocol was introduced, preventing the use of CFCs and allowing the ozone layer to recover (learn more about international treaties here). The presence of CFCs can indicate exactly when that water is from.

Using oxygen to estimate water’s age

We can also look at the Apparent Oxygen Utilisation. The principle is that deep water can’t have oxygen added, so the older the water, the more oxygen will be used up from it, meaning older water has less oxygen.

Despite fluctuations caused by other Ocean movers (e.g. the wind), the waters in the deep North Atlantic are getting older, implying the water is not being replenished as quickly, and therefore that the circulation is slowing. The same is happening at the other pole.

The Ocean is made up of many different ‘bodies’ of water, with different characteristics and names. North Atlantic Deep Water is formed in the Arctic by cold, salty water sinking and flowing south. This water travels all the way to the Southern Ocean, where it meets another body of water.

Antarctic Bottom Water is formed at the South Pole and is the coldest and the densest of them all, the real powerhouse of Ocean circulation. But it is warming and there is less of it. The frost-fuelled engine is slowing.

What would a broken Ocean conveyor belt mean? Explained by Ocean Generation

What would a broken Ocean conveyor mean?

The Ocean would suffer.

Deep sea creatures relying on delivery of oxygen and nutrients would be left waiting, as deoxygenated areas grow. The same would happen for surface species that need the upwelling of nutrients from the deep.

If Ocean circulation stopped, there would be dead zones without oxygen in the deep and starved surfaces with no nutrients to support phytoplankton.

It would impact life on land too. If the circulation of the Ocean slows, global climates will shift. Increased storm intensity, more extreme weather patterns and changes to rainfall. Europe could face far cooler temperatures as the tropical water that brings warmth from the equator slows.

That is quite a big if, and fortunately, the Ocean is resilient. New work has shown circulation has slowed in the 2010s and 2020s by less than in the 2000s. This has been attributed to natural variability pushing against the human-caused weakening.

Every reduction in greenhouse gases, every degree of warming prevented, reduces the stress on our Poles and on our Ocean circulation. Keeping our poles cool keeps our Ocean moving.

Keeping our poles cool keeps our Ocean moving. Explained by Ocean Generation.

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The oldest things in the Ocean: Explained.

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23. 01. 2026 Will Steen

Why krill matter: Krill fishing and conservation in the Southern Ocean

Why krill matter: fishing and conservation in the Southern Ocean.

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The Southern Ocean is one of the most remote places on the planet.

It was only in 1911 that the first human, Roald Amundsen, reached the South Pole. For context, the first powered aircraft, the Wright Flyer, took to the air in 1903. Humanity conquered the skies before it managed the southern continent. The waters here are cold, barely above freezing, yet full of life. These are some of the richest waters in the world.

The main character is just 6cm long. Antarctic krill (Euphausia superba) are small, shrimp-like crustaceans. They snack on the phytoplankton that thrives in the long hours of summer sunlight, trapping and storing similar amounts of carbon to seagrass and mangroves.

Their importance lies in their numbers: krill swarms are vast. The rust-coloured clouds are filled with billions of individuals and can be visible from space. They sustain most of the life around Antarctica. Penguins, seals, whales, fish and sharks all rely on this buffet: krill are a keystone species. More recently, people have joined the party.

Krill fishing has become a divisive topic, being featured in David Attenborough’s Ocean, calls to ban it being promoted at the United Nations Ocean Conference and some retailers withdrawing krill products from their shelves. Meanwhile, countries have applied to increase the catch limits and the amounts of krill being fished are higher than ever.

To understand where we are going, first we can look at where we have been. Why are krill important? What is our history in the Southern Ocean? What is our future?

Antarctic krill are small shrimp-like crustaceans. Posted by Ocean Generation. — *Photo credit: Brett Wilks*

How did we get here?

In 1775, Captain James Cook returned to England from a voyage around the world, in which he had searched for new lands. He found there wasn’t a new continent in the Pacific Ocean (at least not where one was predicted to be) and hypothesised on the existence of Antarctic land behind the ice (which he was correct about).

He had discovered some land on his travels: an island populated by seals and penguins, which was named ‘Isle of Georgia’ in honour of King George III of England. We know it now as South Georgia.

Sealing and whaling in the Southern Ocean

The element of Cook’s report that got attention was the abundance of fur seals on South Georgia and neighbouring islands. These pinnipeds were highly sought after, and between 1778 and 1822 an estimated 1.2 million fur seals were killed for their pelts. The species was almost completely wiped out on South Georgia and the islands.

The rise of industrial whaling then turned focus on to the waters of the Southern Ocean around South Georgia. Factory ships and explosive harpoons reduced the great whales to 18% of their original population. 5% of blue whales were left, and just 3% of humpback whales survived. When the last two whaling stations closed on South Georgia in 1965, 175,250 whales had been killed in those waters.

South Georgia, Antarctica. Posted by Ocean Generation.

When did krill fishing start?

Industrial fishing had been largely unmanaged, and everyone raced to benefit from the natural resources the Southern Ocean had to offer. One by one the marine species of the south had been targeted to great effect, and populations crashed. The focus then shifted to krill.

Industrial fishing for krill in the Southern Ocean increased through the 1960s and 1970s. As the species that formed the foundation of the ecosystem, the alarm bells rang, loud, at the prospect of the krill suffering the same fate as the seals and the whales.

Why are krill important?

Krill are a keystone species

The loss of krill would be disastrous for many different species. Whales, seals, penguins and fish are all krill predators. Less krill means less food for these species.

Southern Right whale mothers have shown a decrease in body condition over the past 40 years, suggesting ecological strain on an animal heavily reliant on Antarctic krill.

The population of krill has been linked with Adelie and chinstrap penguin numbers – when there is less krill, the penguin populations decrease.  And the fur seals, populations freshly rebounded from the hunting of the nineteenth century, are showing declines due to krill availability.

Without krill, life in the Southern Ocean could collapse.

To relay it in economic terms, krill are a vital piece of an ecosystem that provides, conservatively, $180 billion annually in ecosystem services – about 70% of New Zealands GDP in 2024.

Krill are climate champions

It isn’t just the animals in the Southern Ocean that depend on these. Krill are big players in the balancing of our atmosphere. They trap (sequester) a lot of carbon.

As phytoplankton photosynthesise, they take in carbon dioxide. When they are eaten by krill, the krill take on that carbon, some of which is then… dropped off. Krill faecal pellets (poo) alone are estimated to sequester 20 million tonnes of carbon dioxide per year. Depending on the price of carbon, this is worth between $4 and $46 billion.

Marshes, mangroves and sea grass are estimated to absorb 13, 24 and 44 million tonnes per year respectively, so when you add in the extras of krill moults (20 million tonnes) and migration (26 million tonnes), as the researchers say: “it is likely that Antarctic krill is amongst the world’s most important carbon-storing organisms.”

How is krill fishing managed in the Southern Ocean?

Those alarm bells over the fishing of krill led to the creation of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). It was formed in 1980 and entered force in 1982.

The CCAMLR is made up of 27 member states (as of January 2026), with a further 10 ‘Acceding’ states – that support but don’t contribute to the budget or take part in decision making.

The stated aim: to protect and conserve the ecosystem of the Southern Ocean. Article II of the convention states:

The objective of this Convention is the conservation of Antarctic marine living resources.
For the purposes of this Convention, the term ‘conservation’ includes rational use.

This captures a crucial distinction: fishing is an element of conservation, rather than an adversary.

How do you prevent overfishing?

Catch Limits

A general rule of thumb is that you can’t remove so much the population can’t sustain itself. That will vary with species – some animals reproduce a lot faster than others.

Understanding how much of a resource there is, is fundamental to managing it. This is one of the biggest obstacles in the Ocean: the water means you can’t just see (sea). In a field you can see how many cows there are, not true of a shoal of fish.

Acoustic surveying (using noise to find out what is there, like a bat) gives us estimates for the amount of krill. In short – a lot. We estimate there are over 300 million tonnes of Antarctic krill, roughly the same as the biomass of humans.

In the specific area targeted for krill fishing (known as Area 48), the biomass is estimated at 62 million tonnes (coincidentally, roughly the same mass as annual e-waste produced). So, CCAMLR adopted Conservation Measure 51-01. CM 51-01 set a trigger level at 1% of that biomass (620,000 tonnes) – when that is reached, all krill fishing stops, no questions asked. August 2025 was the first time this happened.

How acoustic surveying works: Explained by Ocean Generation.

Marine Protected Areas

Another tool in the toolbox is protected areas – designated places with specific rules. Choosing to avoid fishing in nursery areas, or places with high densities of predators, can ensure the health of the fishery.

The Southern Ocean is home to the first MPA on the high-seas (outside of the jurisdiction of any one country) and the largest. The South Orkney Islands Southern Shelf MPA was created in 2009, and is a no-take zone protecting penguin foraging areas.

The Ross Sea MPA was created in 2016 and is 2.09 million square kilometres, 72% of which is a no-take zone. The MPA has a controversial “sunset clause”, meaning the MPA will expire in 35 years unless renegotiated.

There are four other MPAs that have been proposed, but not yet agreed on.

Has the management of krill worked?

The krill fishery is one of the most closely managed in the world. Every single ship has an independent scientific observer on board to ensure catch and bycatch amounts are accurately reported. There is zero illegal, unreported or unregulated (known as IUU) fishing putting additional pressure on stocks.

Bycatch rates are very low. In 2004, after pressure to report bycatch, it was revealed 292 fur seals had been killed as bycatch. This prompted the fishery to adopt mitigation measures, and since 2010, 39 fur seals have been killed. This is alongside 7 humpback whales and 80 seabirds.

In many senses, this is a great success. Krill populations are stable and there have been little ecological impact from fishing. No other large-scale fishery in the world is as well-monitored, as efficient (in avoiding by catch) or conservative with catch limits. The industry refers to these points as support for increasing the limits.

What's next for the Southern Ocean? Posted by Ocean Generation.

It’s not just ‘how much’: Why location-specific catch limits matter

The numbers look excellent. However, the risk lies in local depletion. Taking 1% isn’t much unless you take it all from one place.

Penguins, seals and whales need the krill within reach. They can travel to find them, but the further they go, the more energy they spend to get there and the less far the meal will go.

To make an analogy:

It is like buying sweets. If you have £10 to spend on sweets, you could either buy lots of different types of sweets or spend all the money just on fudge. If you do the latter, Timmy from down the road might not get the fudge he wants because you bought it all.

To avoid krill fisheries removing the entire quota from one area and leave the local penguins hungry, CCAMLR introduced Conservation Measure 51-07 (CM 51-07). CM 51-07 divided the catch limits in area 48 into Subarea 48.1 (25%, 155,000t), 48.2 (45%, 279,000t), 48.3 (45%, 279,000t) and 48.4 (15%, 93,000t). It added another layer of protection to CM 51-01, but was a temporary measure with an expiry date, to incentivise agreement on long term measures.

In 2024, the CCAMLR failed to agree on new “move on” rules.  These would ensure fishing vessels leave an area once they have caught a certain amount, tackling the issues of local depletion. CM 51-07 expired without replacement at the end of the 2024 fishing season, leaving the krill fishery with only CM 51-01 (when  620,000 tonnes of krill is caught, fishing automatically stops) as guidance.

The CCAMLR currently doesn’t have any special measures to prevent the full quota being taken from the same place.

What is next in the Southern Ocean?

The krill fishery isn’t just dealing with changing policies, but also a changing Ocean.

The Southern Ocean is getting warmer.

The areas of sea ice coverage are decreasing, and a record low in 2023 was 1.02 million square kilometres less than the 1979-2022 average daily minimum. That is the same size as Egypt. The previous four years have seen the minimum sea ice extent drop below 2 million square kilometres.

Krill depend on sea ice. The changing amounts of ice impact the krill’s food – phytoplankton. As juveniles, they stay close for protection and graze off the algae that can grow on it. Less ice means less shelter and less food, which leads to a lot less krill before any fishing has happened. Maximum sea ice extents impact the following summer blooms of krill – more ice means more food and shelter for young krill, who then visibly blossom in the summer. 2025 had the third lowest sea ice maximum, behind only 2023 and 2024.

Since the 1970s, we have been seeing a reduction in the density of krill adults, and in the occurrence of very dense swarms around the Antarctic peninsula. These environmental changes also mean the krill are moving south – staying closer to the pole, where it is colder. This means that the northern ecosystems are losing access to their main food supply. It also means the areas divided up for krill fishing may not capture where the krill are anymore.

Conservation success: the return of the whales to Antarctica. Posted by Ocean Generation.

One of the biggest wins for nature and conservation is the return of the whales.

After population depletion by industrial whaling, whale populations are increasing to their historic levels. As whales return, the amount of krill they eat increases.

Acceptable krill catch limits from 20 year ago may no longer cater for the larger whale populations, which is why re-assessment is so important.

Even if the amounts of krill taken are acceptable, the fishing vessels can still affect the whales. The vessels disturb the whales and can spread krill swarms out more. This means that whales can spend more energy getting the same amount of food, which decreases their body condition and reduces their capacity to reproduce.

The situation gets more complicated when you combine the changes. Less krill is likely to disturb the recovery of whale populations.

Where do we stand on the future of krill?

The warming world and returning whales need to be factored into our management of krill fishing. But recent progress has been slow.

There is a lot of disagreement over the future of the krill fishery. In the meeting of the CCALMR in October 2025, Norway proposed a doubling of the catch limits for krill. At the same time, scientists are calling for a re-evaluation of the limits, as they are based on old data and assumptions. Meanwhile, concern about the exploitation of the Southern Ocean resulted in UK retailer Holland and Barrett withdrawing all krill products by April 2026.

The challenge of consensus

The CCAMLR operates on a consensus decision making model. Everyone has to agree before new measures can be introduced. New MPAs haven’t been agreed because one or two countries have blocked them on the grounds of a lack of scientific evidence and their right to fish for krill and other target species.

What have we learned from exploitation in the Southern Ocean?

There is a lot of hope to be found in the Southern Ocean. Fur seals were given protection in 1909, and their numbers have now recovered to over 3 million. Whaling stations on South Georgia are relics of the past, rusting microcosms of the industry they supported.

The CCAMLR is different to any other fishery. It has learned from previous mistakes and has made decisions based in robust science. A well-managed fishery will always be called too conservative, too limiting, too safe, because it will never reach the point of collapse or decline. So far, krill populations have remained steady, unaffected by us.

The Southern Ocean is changing, and so the fishery must change with it. Climate change, more whales and improved understanding of the ecosystem should all be considered in new fishery management.  There are three things to take from this:

We are capable of facilitating the recovery of the Ocean.
The Southern Ocean, and its krill, are facing new challenges.
We all benefit from the Southern Ocean, and its krill, flourishing.

Krill are small but mighty. They fuel giants and balance our climate. The continuing battle to protect them demonstrates how far we have come. We can understand better than ever the benefits this tiny crustacean imparts as a part of its ecosystem.

We don’t have all the answers, but the progress is reassuring. A relationship with the Ocean that is based in our understanding of the impacts of our actions will be much more productive than one based on the potential profits.

Krill are not the impressive, charismatic Ocean animals that whales and penguins are. But if we fail krill, we stand to lose the rest. Krill can be the species that marks a new chapter in our relationship with the Ocean – one in which we work with our Ocean rather than at the cost of it.

What have we learned from exploitation in the Southern Ocean?

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Will Steen

The oldest things in the Ocean: Explained.

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15. 01. 2026 Will Steen

Narwhals and Unicorns: How the magic of the Arctic has changed

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Are unicorns real? Look to the Arctic Ocean.

Under a clear blue sky, icebergs silently sparkle as they float in the Ocean, occasionally nudging each other. The water between them is a deep blue and still, undisturbed.Until a twisted ivory lance pierces the air, sliding out of the water inch by inch until two metres of tusk are followed by a mottled grey head. The head directs the tusk down again, exhales through the nostrils on top and takes a deep breath, slipping into the frigid waters.

Maybe not quite how you would picture seeing your first unicorn.

Except there’s some bad news. Unicorns aren’t real. We are as disappointed as you are; the closest we can come to a unicorn is a whale that lives in the Ocean:narwhals.

But there was a time not so long ago that people believed the unicorn existed.

Why did people believe unicorns existed?

In the first half of fourth century BC the Greek physician Ctesias provided the first description of a unicorn.He outlined an Indian wild ass(a horse-like animal);with a crimson head and a tri-coloured horn about 28 inches long. He wrote that powdered unicorn horn acted as an antidote to deadly poisons.

Aelian, a Roman writer in 200AD fleshed out the description and noted that only noblemen could afford the horns, they were so expensive.

Early Christianity adopted the unicorn as a symbol of Christ, with the horn as a symbol of the cross of Christ.Through the belief in protection for the self and the soul, the unicorn horn – known as alicorn – became a highly sought after asset.

Unicorn horns were symbols of wealth and power, often displayed in positions of prominence on banquet tables. It was thought that the horn would bubble if dipped in a poisoned chalice, saving the wielder – a popular tool in the medieval banquet hall.

At the peak of its popularity, a complete horn was worth 20 times its weight in gold*, and even powdered horn once cost ten times.

Where did yhe unicorn myth come from? Explained by Ocean Generation, leaders in Ocean education. — *Illustration from the book The history of four-footed beasts and serpents by Edward Topsell.*

Unicorn horns were sought after by nobles, kings and religious leaders in Europe:

For example, Lorenzo de Medici had one valued at 6,000 gold florins (around $1 million). Ivan the Terrible was reported to have paid 10,000 marks for one, and called for it to be brought to him on his deathbed.Martin Luther was said to have been saved from an assassination attempt by powdered unicorn horn, and had a spoon made from the magical substance.

Such a powerful tool befits a queen, and on hearing that Mary Queen of Scots was using unicorn horn to test her food for poison, Elizabeth I offered a handsome reward for another.Privateer and Arctic explorerMartin Frobisher(or&Humphrey Gilbert, both were on the expedition, but different sources credit them) found a narwhal washed ashore in Canada and gifted it to the queen.She was enamoured with it and covered it in jewels. It was said to be valued at £10,000*, approximately £3 million in modern terms. She also handed a gilted and bejewelled unicorn horn drinking vessel down to James I.

Even the Pope, one of the main focal points of power and wealth at the time, was involved.Pope Clement VII gifted Francis I of France a unicorn hornon a silver stand.

In the 1660s, King Frederick III ordered the building of a coronation chair. This chair was made using several unicorn horns and served as the centrepiece of Danish coronations until 1840.

But as we know, unicorns aren’t real. Where are these horns coming from?

Unicorn horns were sought after by European nobles. Posted by Ocean Generation. — *The Trustees and Factor and Commissioner of the Walker Trust / National Museums Scotland*

Where did tales of unicorn horns come from?

Most of the Roman and Greek accounts of unicorns were;likely based on stories from travellers coming across rhinoceros in India and Africa. But after these initial accounts describing the horn as straight, Christian art from about 1200 changed its view of the unicorn.

Unicorns now had spiralled horns. There is only one animal that possesses a straight, spiralling ‘horn’ – the narwhal (Monodon monceros).And it isn’t a horn at all, but a tooth.

Christian art from about 1200 depicted unicorns with spiralled horns.

What you need to know about narwhals: unicorns of the sea

The name comes from the Old Norse nárhval, meaning corpse whale. Narwhals have mottled grey skin not dissimilar to rotting flesh and like to lounge at the surface – behaviour known as logging. Combine the two and you can understand why the Viking explorers named them.

Narwhals are homebodies. They have ‘high site fidelity’ -meaning they stick to the places they like and will go back to their favourite spots. They can be found in the Canadian Arctic, through to East Greenland,Svalbard and the western Russian Arctic.

What is a narwhal’s ‘horn’?

The ‘horn’ of a narwhal is one (or in rare cases two) of the incisors,so is a tusk rather than a horn at all. All narwhals have two tusks embedded in their top lip.

Most commonly, males in their 2^nd or 3^rd year will have the front left tusk erupt through their top lip, growing with age to reach 1.5-2.5m long. Around 3% of narwhals are anomalies, with some females growing tusks, some males growing two or none at all.Double tusks in narwhals are about as common as an extra finger in humans.

What do narwhals use their tusk for?

The use of the tusk is still under debate.

The first theories were that narwhal tusks were used for piercing prey or breaking up ice to make breathing holes. Observers supposed they could also function as a defensive mechanism or a cooling system. However, these theories are either discredited or unproven. The real uses are even more spectacular.

What do narwhals use their tusks for? Explained by Ocean Generation. — *NIST/Glenn Williams*

Dental Displays

Studies suggest that narwhal tusks are sexually selected. Male narwhals will use their tusk as a display feature in competition with each other, and bigger is better. The size of the tusk has been shown to positively correlate with teste size – so could be an easy indicator for the females to see which males are most fertile. Sometimes, size does matter.

Where males with similar tusks meet, they may fight –male narwhals show far more scarring on their heads than juvenile and female narwhals and 40-60% have broken tusks, but this hasn’t ever been observed.

What is sexual selection?
Sexual selection is a special type of natural selection, where traits that increase reproduction will be passed on.

Fish Fencers

But it isn’t just for showing or skirmishing. Using drones to study the narwhals’ behaviour, researchers saw the tusks in action. They could use the tusk to guide the fish, chasing it. They even saw the tusk being used, as a thresher shark uses its tail, to hit the fish, stunning it ready for eating. The scientists involved think there could even have been an element of play.

Temperature Taster

In 2014, we discovered that a narwhal tusk was full of holes and nerves. This could mean that it can operate as a water sensing tool for the narwhal, and they can ‘feel’ changes in water saltiness (salinity) and temperature. They show elevated heart rate when the horn is exposed to very salty water and fresh water, suggesting they can detect it.

‘Feeling’ your surroundings can be very useful for navigation, when diving deep and moving between their favourite spots. It could also save their lives. Seawater freezing depends on the temperature and salinity of the water – saltier water needs to be colder before it freezes. By knowing the temperature and salinity of the water they are in, they are detecting when the water is likely to freeze, trapping them from the air to breathe.

This could also be used in hunting – those narwhals we’ve seen using their tusks to ‘chase’ fish? They could be using their swirly sensor to detect the fishes’ movements through pressure changes in the water, even faster than they can see them

Narwhals are nicknamed the unicorns of the sea. Posted by Ocean Generation. — *phys.org*

Are narwhals magic?

So, we have a tooth that helps guide them through the icy waters like Rudolph’s nose, zero in on prey like a laser guided missile and show off their suitability to be a parent.

A narwhal’s tusk could enable them to tell when ice is going to form and find prey hiding in the dark as they can dive over a kilometre (3,281 ft) down, where no light can reach.

Unicorns might not be real, but this all sounds like magic.

Does something lose its magic just because we understand how it works?Whether it is magic or incredible biology, the enchantment of the narwhal is threatened by a changing world.

How is the narwhals’ world changing?

The opinions and doting of nobles across Europe and the world meant nothing to the narwhal.After years of hunting operations, narwhals are now enduring other changes, this time in their home. Climate change, caused primarily by the human burning of fossil fuels, is hitting the polar regions, where narwhals live, the hardest.

The Arctic is warming faster than the rest of the world. This is known as polar or Arctic amplification(AA). AA has resulted in the Arctic warming by as much as four times the rest of the globe. Since 2006, the air temperature in autumn and winter has increased by more than twice the global average.

Narwhals live around the Arctic Ocean. Posted by Ocean Generation. — https://doi.org/10.1016/j.marpol.2013.10.005

Why do narwhals live in the Arctic Ocean?

Narwhals like it cold.Where the sea is warmer, there are less narwhals. Why? This could be to do with their prey – one of their favourites, cod, are known to grow better in water temperatures of less than 2 degrees.

It could also be to do with their supreme adaptions for the coldest places on the planet – they may overheat at higher temperatures. No one wants to be wearing a thick winter coat on a hot summer’s day.

How is climate change impacting narwhals?

There is less ice. November 30 2025 saw the lowest area of Arctic ice on that date on record. The previous 20 years have given us the 20^th lowest sea ice minimums on record, and there is 95% less old sea ice (over 4 years old) than the average from 1979-2004.

Ice is an important part of the lives of every animal living in the polar seas.The loss of sea ice has been shown to change the diet of the narwhal as they can’t eat ice-based (known as sympagic) prey, so they eat more open-water (pelagic) species instead.

Through burning coal and mining for gold, humans have increased the amount of mercury in the environment.Less ice means there is more bioavailable mercury. The result: the narwhals are exposed to more mercury.Increased mercury levels can impact the reproduction and immune systems of narwhals. How do we know this? Through analysing narwhal tusks, which give us an insight into their life history. The magic tusks are whispering to us.

The reducing ice also means there is more human activity. We are a noisy bunch, and narwhals have shown to be sensitive to ship noise, reducing their deep dives for food (and given they are inefficient in their dive success, they need them).

The Arctic Region is warming four times faster than the rest of the world.

How are we preserving the magic of the Arctic?

Narwhal hunting is monitored and almost every whale caught is for the subsidence of the indigenous Inuit people. The population is difficult to track, especially without a reliable baseline. However, the International Union for the Conservation of Nature assessed the population in 2017 and shifted the status from Near Threatened to Least Concern. The narwhal is doing well so far.

The isolation of the Arctic and the changing attitude towards cetaceans means the narwhal hasn’t had to deal with a multitude of human pressures. But more than ever, those pressures are finding them where they log.

Research will continue to develop quieter boats, and policy will increase protected areas. The narwhal is one example of a bit of remote magic we are trying to keep.

Climate change is being tackled head on, with an energy transition in full flow, electric vehicles going from strength to strength and global emission increases are slowing. We will be the generation to see the transition to human flourishing not coming at the cost of our natural world, for the first time.

But within this, driving this, is being able to see the magic of the unicorn, not as a made-up money-making monopoly manufacture, but in the reality of the narwhal and its beautiful, magical tooth. See the magic, spread the magic – that is what will lead to us protecting the magic.

*Wexler, P. (2017). Toxicology in the Middle Ages and Renaissance. Academic Press.
Cover image by Проектный офис Нарвал

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Will Steen

The oldest things in the Ocean: Explained.

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13. 01. 2026 Will Steen

From classroom to COP30: Questions from children to climate leaders about Ocean protection

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If a group of 7–11-year-olds could interview delegates at COP30, what would they ask?

Well in November 2025, Ocean Generation made this happen. We worked with 5 young Eco Ambassadors at Ballard School in New Milton, UK as they interviewed Professor Matt Frost, Head of International Office at Plymouth Marine Laboratory as part of the COP30’s Virtual Ocean Pavilion’s series of youth-led interviews.

What is COP?
COP (Conference of the Parties) is the UN’s annual climate summit. During the conference, parties negotiate climate action and review progress. COP is also a platform for scientific studies and activism. Read more about COP here.

Ocean Generation’s Youth Engagement Lead, Dr Gemma Connell, mentored the young people through the process and was so proud when they wrote their own (very difficult!) questions for Matt, giving him a bit of a grilling!

It was heartwarming to witness Matt’s honesty in his responses to the young people. He discussed where the problems are in the COP space, and most importantly – what we can all do to protect our Ocean.

Join the Eco-Ambassadors as they ask Professor Matt Frost the important questions around COP30, the importance of the Ocean and what his favourite sea creature is.

So, you wake up at COP30, what are you doing? What does you day look like? (Freddie’s question)

Matt’s answer:

Wake up, check the times on everything. You don’t want the changing time zones to lead to you missing events and meetings.

Planning where to be that day, making a list of places and times I need to be somewhere.

The first day and the start of every day includes a lot of security. Making sure everyone has identification and the right badges to get through the security measures that are in place protecting some of the world’s most important people.

COP can involve hundreds of thousands of people, so just working out where everything and everyone is, is a challenge. Got to make sure you know where the good coffee shops are.

“The fun bit is that you walk around, and you meet all sorts of people.”

Not just meetings or speaking events, but you might find yourself doing some media as well.

“Recently I was at a COP when I bumped into Tom Heap, who is one of the presenters on Countryfile. He said, ‘do you mind doing an interview while you’re here that we can put on Sky News?’”

Every evening there will be a reception, meeting all sorts of people from government ministers to scientists.

Youth-led interview series at COP30 — Photo by Ballard School

Young eco-ambassadors from Ballard School interviewing a climate scientists as part of COP30 — Photo by Ballard School

What are your expectations coming to the COP30 and what would you consider a successful result for the Ocean? (Toby’s question)

Matt’s answer:

“For many years, when people came to these meetings, they were all worried about what was going on on the land.” Matt noted how the conversations would focus more on forests, trees and farming, “but nobody really thought about the Ocean.”

“So, over the years, we’ve had to explain to people that our planet – and I’m sure you know this, being Eco Champions – is mostly water. The Ocean is most of our planet. So, one of the main things that is a success every time we go to these meetings is to make sure that everybody is talking about the Ocean.”

Every leader talking about the Ocean is a success. The next step is encouraging action.

The people at these meetings don’t have the power, they can go back to their governments to convince them to act.

For example, the UK government going home and taking direct action to address the issues in the Ocean through laws and funding would be a real success from COP30.

The Ocean has gradually grown in prominence on the global stage.

Ocean Generation’s note:

Six years ago, COP25 recognised the connection between Ocean and climate, COP26 called for Ocean action to be integrated in work programs and COP27 encouraged countries to include the Ocean in their national climate goals.

At COP30, the Ocean was formally included in the COP30 Action Agenda. It was the first time a COP decision included a specific Ocean angle, with goals and commitments. This included investing in marine conservation and renewable energy, reducing the environmental and ecological impacts of shipping, supporting aquatic food solutions and reducing the impact of coastal tourism.

Practical tools were launched at COP30 to help achieve the goals. An Ocean Breakthrough Implementation Dashboard was launched to monitor country progress across those five areas (nature conservation, renewable energy, shipping, marine food and tourism). The Marine Biodiversity and Ocean Health Breakthrough and Roadmap gives the standards and methods to tackle Ocean assessment and actions.

While COP30 included the Ocean more deeply than previous COPs, there was a lack of financing and binding agreements to ensure countries take action. It is now over to them to build on the outcomes of COP30 and take Ocean action.

How can governments encourage private companies to not use single use plastic? (Leo’s question)

Matt’s answer:

If I could get a brilliant answer to that it would solve one of the world’s biggest problems. So, I will do my best and honestly, Leo, if you and your friends have got ideas… we need some help with this.”

As well as a pollution problem, plastic is also a climate problem, as 99% of plastics are made from fossil fuels.

Governments like the UK have been banning things like plastic straws, microbeads in cosmetics and charging for plastic bags.

Should we ban everything? “I don’t think that will help ultimately…”. It is a global problem and needs to be addressed globally. The Global Plastics Treaty is an opportunity for governments to make a real difference. Read more about the treaty here.

Companies are willing to cut down on plastic but need incentives to do so. Encourage is a great word in the question.

“They [world leaders] can make it difficult by putting taxes [on plastic] and making it more expensive to use single use plastic. But ultimately… governments will only do so much.”

Government action can be encouraged by what we buy and say.

99% of plastics are made of fossil fuels. Posted by Ocean Generation, leaders in Ocean education.

Ocean Generation’s note:

The difficulty in banning all plastics, is where we haven’t yet found an affordable alternative which does the same thing as plastic but doesn’t have the impact on the environment.

This is particularly difficult in industries such as healthcare, where single use plastic is often used to keep patients, doctors and nurses safe. We can’t ban all plastics without looking at the other consequences that might have – context is very important! Read more about if plastic is good or bad here.

Are there plans to introduce whale friendly cruise routes to reduce noise pollution in the seas? (Lily’s question)

Matt’s answer:

Yes there are plans for whale friendly shipping, but we really need the shipping companies to start doing this now.”

Ships are big contributors to climate change, producing air pollution as they burn fossil fuels to power their engines.

There are much more ships on the Ocean at any one point – over 70,000. There are two main ways they cause issues for marine life such as whales – noise pollution and ship strikes.

Whale friendly cruise routes hope to minimise the impact of both of those things. The International Maritime Organisation and the International Whaling Commission are trying to implement rules on shipping. These include go slow zones where whales are known to feed and live, and special routes that avoid whale “hotspots”.

It is down to the individual ships, shipping companies and cruise companies to act on the advice of the IWC and IMO.

How marine shipping routes and whale's migration routes overlap. Explained by Ocean Generation.

Ocean Generation’s note:

Exact numbers of whales killed by ship strike are difficult to quantify, as data suffers from underreporting.  But recent work has shown that global shipping traffic overlaps with about 92% of whale species’ ranges. Of that, only 7% of the areas that are high-risk for whale-ship collisions have any protective measures. Protecting just 2.6% more of the Ocean would eliminate many high-risk areas with minimal impact to shipping times.

As Matt says, there are two main solutions. Slower ships give all marine life more time to dive or swim away, avoiding collision. Slowing ships to 10 knots can reduce the the number of whale deaths by 30%.

The other approach is by re-routing ships from collision hotspots. In the Mediterranean, rerouting ships away from the Hellenic Trench has reduced the risk of collision by an estimated 27%.

95% of hotspots fall within the exclusive economic zones of a country, so, each country can implement protective measures in coordination with the IMO recommendations. Whale safe routes are in reach.

Does creating the infrastructure in order to host COP30 and transporting leaders there outweigh the positive outcomes of the conference?  Do you assess the carbon footprint and is there a plan to offset this? (Sean’s question)

Matt’s answer:

The concern is that we might not have these conversations if we weren’t all in the same room. Yes, we carbon offset but there is going to be some environmental impact. We think the positives outweigh the negatives.

“At the moment we feel that if we didn’t go, who’s going to be there to speak up for good science, to speak up for the Ocean, to speak up to actually look after things? And the danger is that, if all the people who feel very strongly about carbon decide not to go to the COP for the reasons you’ve said, then it could be left with the people that don’t really care much about it.”

Ocean Generation’s note:

One of the intentions of hosts Brazil was to deliver a carbon-neutral COP30. They delivered this by offsetting their calculated emissions. They calculated that COP30 produced 130,000 tonnes of carbon dioxide or equivalent greenhouse gases. To counter this, they purchased 130,000 UN-certified carbon credits. The money for these credits goes towards carbon-negative projects, so COP30 is carbon-neutral in principle.

However, this calculation only considers the emissions generated by hosting. The bulk of emissions are likely generated by the travel of attendees. There is no comprehensive calculation of these emissions. A large part of that relies on the attendees doing what they can to reduce environmental impact.

“You can ask me again next year and maybe I’ll answer differently, but this year the positives outweigh the negatives.”

Was COP30 carbon neutral? Explained by Ocean Generation. — *Photo by Fernando Llano/AP*

Is COP30 going to be used for fossil fuel deals like the last one? (Sean’s question)

Matt’s answer:

“I can’t promise that that will never happen at any COP.”

Some people will want to see things stay as they are, but there are enough people with good intentions there to know that good things will come out of it. Multilateralism (global cooperation), connecting climate change messages to individuals and accelerating implementation are all main aims of this COP.

I’m hoping the good things will outweigh the others.

Ocean Generation’s note:

At COP29, there was backlash against the hosts, Azerbaijan, as one of their senior officials was found to be conducting meetings to coordinate fossil fuel deals. Find out more of what happened at COP29 in our article here.

What is the extent of the impact of pumping carbon back into the Ocean underneath the seabed? (Lily’s question)

Matt’s answer:

It’s possibly helpful, capturing carbon dioxide from the atmosphere and tapping it. However, there are risks – if it leaks it can cause harm to marine life and return the carbon to the atmosphere.

We’re asking that we [humans] don’t do it until we know more about the effects of it.

“If you went to the doctor and said, ‘I feel really poorly,” and the doctor said ‘well, I’ve got some medicine for you… I don’t know if it works very well, and it might make you really ill, but I don’t actually know that we haven’t tried it.’ Would you take that medicine?

Impact of pumping carbon back into the Ocean: explained by Ocean Generation.

What key messages would you like us to share with our school community in order to look after the Ocean better? (Freddy’s question)

Matt’s answer:

There is an ongoing problem that people don’t really understand the Ocean. They don’t know what is in it, they don’t really understand it, and they don’t know that we rely on it.

We need to remind people that most of our planet is Ocean. When the Ocean is healthy, we are healthy.

We rely on the Ocean for our food, our breathing air and our mental health.

If we look after the Ocean, it will look after us.

Read more about how the Ocean keeps us alive here.

Toby’s surprise question: What is your favourite marine animal?

Matt’s answer:

Matt’s answer: the leafy sea dragon!

Ocean Generation’s note:

The leafy sea dragon is a fish closely related to seahorses and pipefish. The name of its genus, Phycodurus, comes from the Greek words for seaweed (phûkos) and skin (derma), encapsulating its amazing camouflage. It can change the colour of its skin to match the seaweed around it and moves through the water like a drifting frond.

Leafy seadragons typically swim solo, but will court each other through dance, mirroring each other’s movements. Males carry the eggs for 6-8 weeks on a specialised patch under their tail, before ‘giving birth’ to 100-250 20mm baby leafy sea dragons (about the size of a peanut).

The leafy sea dragon is a fish closely related to seahorses. Posted by Ocean Generation.

Matt asked the students: what would the Eco Ambassadors’ message be for him to take to COP30?

Toby answered, “Plant more trees!”

A week later, the Eco Ambassadors planted 30 saplings after school, doing their bit to live up to Toby’s “plant more trees!” answer.

Alex Bellars, teacher at Ballard School said:

“Our Eco-Ambassadors absolutely loved taking part in the Virtual Ocean Pavilion interview with Professor Matt Frost on 6th November, 2025. It was inspiring to know that their voices and ideas formed even a tiny part of the global conversation at COP30!

It was especially cool to know that our pupils were the youngest participants in the Virtual Ocean Pavilion – and therefore possibly at the whole of COP30 itself. And it was wonderful to see Toby grab the chance to put Matt on the spot with an unplanned bonus question!”

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Will Steen

The oldest things in the Ocean: Explained.

Monthly: Impact in your inbox.

25. 11. 2025 Will Steen

Marine discoveries and Ocean wins in 2025

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What were the Ocean wins in 2025?

The past year has seen some amazing developments in our understanding of and our relationship with the Ocean. We’re unpacking: what Ocean discoveries have we made, what Ocean protection have we brought in and what Ocean recovery have we seen in 2025?

Jump to:

What Ocean discoveries happened in 2025?

New clownfish related discoveries

Over the course of 2025, there have been a series of discoveries centred around the clownfish, made famous by Nemo and Marlin in Finding Nemo (see our scientific analysis of the film here).

How does the clownfish avoid being stung by the anemone?

By having lower levels of sialic acid on their skin, clownfish avoid being stung by anemones. Sialic acid can be found on the outer surface of most animals – it is important in cell-to cell communication and immune response. The nematocysts (stinging cells) of the anemone have a special trigger, to avoid the anemone constantly stinging itself. Researchers found the fish that can live in an anemone have low levels of sialic acid, to ‘hide’ from the anemone, and avoid triggering its stings.

We discovered that the relationship between clownfish and anemone isn’t as one-sided as it may seem.

Anemonefish have been observed feeding their anemones large food they can’t eat, or extra food after they have eaten their fill. This has also been shown to increase how fast anemones grow.

Why do fish carry anemones around in their mouths?

Clownfish aren’t the only ones buddying up with anemones. Several species of fish have been photographed holding larval (baby/ juvenile) anemones in their mouths.

The assumption is that they are effectively arming themselves with marine (live) pepper spray. Predators can be warded off with a nasty sting. The anemones also benefit, as the young fish can swim and be swept much further than the anemone would normally reach.

The young fish have a predator deterrent, and the anemone gets a lift to a new neighbourhood.

Why do fish carry anemones in their mouths? Posted by Ocean Generation, leaders in Ocean education. — *Picture credit: Afonso et al. 2025, J Fish Biol. DOI: 10.1111/jfb.70214*

What new Ocean species were discovered in 2025?

A new species of manta ray was distinguished in 2025, adding a third species to the manta ray family.

Until 2009, there was only one species of manta ray. In a study focussed on morphological characterisation, analysis of colour, teeth and other traits differentiated the reef and Oceanic manta rays.

In 2025, after years of speculation, it was confirmed that there was a third species of manta.

Lead author of the study identifying the Oceanic and reef manta species, Dr. Andrea Marshall, had theorised a third species after diving in the Atlantic Ocean with manta rays she didn’t recognise. Years of study, including the description of a type specimen and genetic analysis, have confirmed her hypothesis: a third species of manta ray exists.

New species of manta ray was described in 2025. — *Picture credit: Leo Francini a; Guy Stevens/ Manta Trust b, e; Rawany Porfilho c; Mauricio Andrade d; and Nayara Bucair f*

Facts about the newly discovered manta ray:

Mobula yarae, more commonly known as the Atlantic manta ray, are named after Yara, the ‘mother of waters’ from Indigenous Brazilian mythology.

Telling them apart from other manta rays starts with size: they reach an approximate size of 6m across, sitting between the Oceanic and reef manta in size. A ‘V’ shaped white shoulder patch, lighter colouration around the mouth and eyes and dark spots confined to the belly rather than between gill slits are the key identifying features.

The Ocean Census announced that it has facilitated the discovery of 909 new Ocean species.

The program, in its second year of running, hopes to fast-track Ocean discovery, and so far has increased the annual speed of species discovery by 38%.

A new kind of shark discovered

Sticking with our elasmobranchs (cartilaginous fish that include sharks, skates, and rays), a new kind of guitar shark was discovered off the coasts of Mozambique and Tanzania. It joins 37 other guitar sharks in one of the most threatened vertebrate families, with two thirds of them threatened.

New species of snailfish in the deep-sea

Looking deeper in the Ocean, a new species of snailfish was discovered 3,263m deep.

The suitably named ‘bumpy snailfish’ is only two to three inches long and was one of three new snailfish species found on the expedition led by the Monterey Bay Aquarium Research Institute.

There are over 400 species of snailfish, and the family holds the record for the deepest dwelling fish, with one found 8,338m deep.

New Ocean species discovered in 2025. Posted by Ocean Generation. — Picture credit: Guitar shark: Sergey Bogorodsky / The Nippon Foundation-Nekton Ocean Census, Snailfish: MBARI, Sponge: The Nippon Foundation-Nekton Ocean Census Schmidt Ocean Institute © 2025 Coral: Xu et al., Zootaxa, 2025

Meet a newly discovered sea sponge: the Death-ball sponge

As one of the more notably named, the death-ball sponge (Chondrocladia sp. nov.) received a lot of press.

Where most sponges unobtrusively filter the water for food (ensuring highly efficient nutrient circulation where there isn’t much to go round), this new species has a number of ‘balls’ covered in tiny hooks to trap their prey.

New deep-sea discoveries with celebrity nicknames

There were a couple of famous characters whose semblances were discovered in the deep Ocean.

A deep-sea coral first spotted in 2006, but formally described this year, was given the name Iridogorgia chewbacca, due to its long hairy branches.
An iridescent scale worm found in the freezing waters of Antarctica was given the nickname ‘Elvis-worm’, its sparkling scales shimmering in the deep like the sequins of the King of Rock and Rolls’ jackets in Las Vegas
And a bonus one (not a new species): the colossal squid was caught on camera in its natural habitat for the very first time. This one wasn’t all that colossal: it was a juvenile just 30cm long.

What Ocean protection happened in 2025?

60 countries ratified The High Seas Treaty in 2025

In September, the Agreement on the Conservation and Sustainable Use of Marine Biological Diversity of Areas beyond National Jurisdiction reached 60 ratifications, the milestone required to start the countdown to it becoming legally binding. From 17January 2026 the agreement, also known as the biodiversity beyond national jurisdiction (BBNJ) or High Seas Treaty, will enter force.

Read more about the High Seas Treaty here.

The High Seas Treaty will come into force in January 2026. Posted by Ocean Generation.

Many countries have been protecting the Ocean off their coastlines in 2025.

Countries haven’t been hanging about, waiting for the High Seas Treaty, they have been getting on with Ocean protection in their own patches.

Marine Protected Area, or MPA, is a general term for an area of Ocean in which human activities are managed or limited to protect the marine world. Depending on what they are aiming to protect, they can have different rules. Some will allow sustainable fishing and recreation; others may be no-take zones where no fishing is allowed.

What is the largest marine protected area in the world?

French Polynesia announced the creation of the world’s largest marine protected area in 2025. The protection of their entire exclusive economic zone, an area of 4.8 million square kilometres, now includes 1.1 million square kilometres of highly protected waters.

An exclusive economic zone is the area of Ocean extending up to 200 miles from the coast of each country, in which they have the rights to explore and utilise any marine resources.

A huge no-fishing zone has been expanded in the South Atlantic Ocean:

For Marine Protected Areas (MPAs) around South Georgia and the South Sandwich Islands (not where sandwiches were invented), the ‘no take zones’ where no fishing can occur have been expanded to over 470,000km2, 38% of the MPA. This is to help protect the migration routes of humpback whales.

How whales are being protected in marine sanctuaries:

That isn’t the only help we’ve given our whale friends. In October, a proposal for a huge marine sanctuary in the North Atlantic was approved. Macaronesia is an area including the Azores, Madeira, the Canary Islands and the Cabo Verde islands. It’s rich in marine biodiversity, hosting 32 different species of cetacean. (Cetaceans include whales, dolphins and porpoises.)

The new marine sanctuary will hope to protect the Ocean from increasing pressures of boat traffic, underwater noise, industrial fishing and future threats such as deep-sea mining.

Do marine protected areas really help protect the Ocean?

In a little win of its own, a research paper was published this year that showed that fully and highly protected marine areas do work.

There have been concerns that enforcement around MPAs isn’t feasible, any fishing vessels can just ‘go dark’ – turn off their identification systems and continue poaching.

But analysis using artificial intelligence and satellite imagery has shown very little industrial fishing activity in highly protected MPAs. Conversely, there was substantial activity in MPAs with low protection.

We’re protecting more of the Ocean, and it is working.

What is the EU Ocean Pact?

On money, the European Commission launched a unified framework for EU Ocean policy in 2025, backed by a €1 billion investment in the Ocean, with six priority areas including: habitat restoration, decarbonisation of maritime sectors, blue economy competitiveness, coastal/island community support, Ocean diplomacy and innovation.

Progress on cutting shipping emissions

Member States of the International Maritime Organisation agreed a global standard for decarbonising shipping: fuel‑intensity reductions, global emissions pricing for ships, and a fund for low/zero‑emission marine fuels.

The agreement was agreed but not formally signed, as in a meeting in October 2025 delegations from Saudi Arabia and the United States lobbied for a delay.

This is half a win this year and will hopefully be a full win for our Ocean in 2026, in a sector that accounts for around 11% of global emissions in transport.

2025 saw progress cutting emissions from the shipping industry

What Ocean recovery have we seen in 2025?

Are whale populations bouncing back?

In a paper published towards the end of 2024 that examined historic databases on whales, it was suggested that we underestimate the longevity of whales by some distance.

How old do whales get?

Our estimates for the average age of whales were first shaken in 1979, when Japanese whalers found individual blue and fin whales that were 110 and 114 years old respectively. Prior to this, we understood these animals to live to 70 years.

This 2024 paper attributed the lower perceived longevity to our success in whaling. Whales weren’t living as long because we were hunting them.

But the world is changing. Whaling was made illegal in 1987, and populations have shown promising signs of recovery. Over the course of 2025 there were several markers of a better world for whales, and hints of the future we are creating for them.

The Atlantic Northern Right Whale, one of the most endangered whales, has enjoyed an increase in population, up 8 individuals to 384 whales. This is off the back of a decade in which the population declined by 25% between 2010 and 2020 due to ship strikes and entanglement.

2025 saw the cancellation of the Icelandic fin whale season, meaning once again no fin whales were killed due to an unfavourable market, marked by diminishing demand for whale products and rising costs.

Atlantic Northern Right Whale population is bouncing back. — *Picture credit: Whale and Dolphin Conservation*

Who is ‘crush’ing it? Green turtles are no longer endangered.

It’s a good time to be a green turtle (Chelonia mydas). The species, made famous by Crush and Squirt in Finding Nemo, has been upgraded on the International Union for the Conservation of Nature (IUCN) Red List, from Endangered to Least Concern.

To best help them, we had to understand what was hurting them. Green turtles (and other sea turtle species) have long been hunted for their meat and their eggs, so legally protecting them was a good first step.

When did we start protecting sea turtles?

Legal protections started coming in in the second half of the 20^th century, with bans such as that on Aldabra Atoll in 1968 safeguarding turtle mothers and their eggs. Since that ban, green turtle egg clutches have increased 410−665%.

Even without the pressures of hunting, turtles still faced a struggle, becoming the poster of plastic pollution and entanglement in fishing gear, and facing the realities of a changing Ocean.

But conservation efforts have continued. Excluder devices (devices designed to prevent bycatch) have been implemented on fishing gear to avoid entanglement. Nesting beaches have been protected from light pollution that could lead hatchlings away from the Ocean, or plastic pollution that could tangle or choke them. Turtle hatchlings have been released at sea to give the population a boost.

Green turtle numbers are now up 28% compared to the 1970s.

Some sub-populations are still struggling and need help, but it shows us, again, that the Ocean has a great capacity to recover when we allow it.

“The ongoing global recovery of the green turtle is a powerful example of what coordinated global conservation over decades can achieve to stabilise and even restore populations of long-lived marine species,” – Roderic Mast, co-chair of IUCN’s Species Survival Commission Marine Turtle Specialist Group.

Green sea turtles are no longer endangered. Posted by Ocean Generation.

Dam Good News for salmon

In 1878, a lamp turned on. In itself, not a remarkable event, but this lamp was special. It was powered by water.

Cragside House in Northumberland, England, saw the birth of hydroelectric power. Within ten years, hundreds of hydropower stations were running around the world. It remains the third largest source of electricity globally, behind coal and gas. Until 2004, it represented over 90% of the world’s electricity generated by renewables and is still over 50%.*

Benefits of hydropower

Our World in Data compiles the data to examine its benefits. Hydropower is incredibly safe, with the 1.3 deaths per terawatt hour of electricity produced far lower than coal’s 24.6, and almost all from a single event: the Banqiao Dam Failure in China in 1975, which killed 171,000.

Hydropower is very clean, producing an average of 24 tonnes of CO2 equivalent per gigawatt hour, compared to coal which produces 970 tonnes. A world without hydropower would likely be a world that had burned more fossil fuels.

Disadvantages of hydropower

However, hydropower isn’t all turbines and waterfalls – it comes with its limitations. It’s expensive, especially in upfront cost. It also has an environmental impact beyond carbon emissions.

Huge dams create reservoirs, flooding land and cutting off rivers. Cutting off the rivers can lead to drought or famine downstream. Reservoirs can emit greenhouse gases by creating large areas of stagnant water full of decomposing material. As solar and wind have become far cheaper and more accessible, there is less need for the large projects.

Salmon, returning home after 100 years:

In 2023, the world’s biggest dam removal project re-opened the Klamath river in California and Oregon.

The project was initiated by local populations after 30-70,000 salmon died below the dams in 2002 due to low flow, the costs of maintenance and repair coupled with environmental costs and the reservoir’s proclivity to harmful algal blooms.

This year, the salmon returned to the Chiloquin Basin for the first time in over 100 years.

“A hundred and fifteen years that they haven’t been here, and they still have that GPS unit inside of them. It’s truly an awesome feat if you think about the gauntlet they had to go through.” said the visibly giddy Klamath Tribal Chair William Ray, Jr.

Salmon returned to a river in California after the removal of a dam.

This is a story mirrored elsewhere in the world too – salmon returned to the river Don in England for the first time in two centuries this year.

As we explored in some articles earlier in 2025, rivers and residents like salmon are vital in connecting different ecosystems.

Hydropower can prevent the salmon migrating and breeding in their ancestral waters and poison the rivers they grow up in. Losing that connection impacts the people and life all along the river.

We need energy to reinforce our high quality of life. That used to come at the cost of our natural environment. However, we are more aware of that impact, and we are getting far better at diminishing it. Stories like this are sprinkled with glimpses of a bright future, in which humans can flourish with nature.

This pattern – discovery igniting protection, protection enabling recovery – reflects how our relationship with nature has evolved over decades, not just this year.

The Ocean wins of 2025 demonstrate a shift in our relationship: we are learning to value and safeguard our seas, and in return, the Ocean is proving its remarkable capacity to heal.

In ten years, we hope stories of recovery and flourishing will dominate the narrative, as the need for more protection fades.

Discovery is good too; it will always be fun to hear about new death-ball sponges and bumpy snailfish.

* Energy Institute – Statistical Review of World Energy (2025)

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Will Steen

The oldest things in the Ocean: Explained.

Monthly: Impact in your inbox.

16. 10. 2025 Will Steen

What deep-sea creature is the best Halloween costume?

Five deep sea creatures that make perfect Halloween costumes. Posted by Ocean Generation.

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Trying to avoid spending money on a new Halloween costume you’ll only wear once?

Trying to be environmentally friendly? Just got a last-minute invite to an Ocean-themed costume party? Just love the deep sea? We got you. These deep-sea creature costumes should help you bring the Ocean to the Halloween party.

For the main event: dress up as an anglerfish

Anglerfish female and parasitic male. Posted by Ocean Generation. — *Photo by Edith A. Widder*

A classic. Anglerfish are the posterchild for the deep sea. Who hasn’t dreamt of these creatures lurking in the depths, with huge teeth and a glowing orb of light to draw you in until it is too late to escape.

Finding Nemo put this fish on the map for many of us (but it wasn’t completely accurate – see here).

We are using anglerfish liberally here: there are many different animals that could be referred to as anglerfish, but we are talking about deep-sea species from the Ceratioidei family.

The name means horn bearers, referring to the modified dorsal spine that for many species has a lit up lure at the end.   Anglerfish host bacteria in their lure to generate light. This attracts fish, shrimp or squid close enough for the anglerfish to suck into its mouth, which is very big for their body.

Eyes too big for their stomach? Not likely for the anglerfish. They have extendable stomachs that can hold fish twice their size (useful if you aren’t sure when your next meal will swim along).

The main point to hit in your costume is the lure – the esca. Face paint for some big teeth would certainly add to the look.

What you need for the anglerfish Halloween costume:

Light source (headtorch, LED lights etc.)
Something to hang it off
Hat
Black clothes

I have done this outfit before on very little notice, using toilet rolls as the illicium (the modified dorsal spine tipped by the esca). Other good options are repurposed clothes hangers or just a good-sized stick from outside. Attach your esca to your illicium (some glue, blue tac or tape), attach your illicium to your hat and away you go!

A battery pack on the back of the hat can act as a good counterweight to your lure.

Now just watch your work entrance everyone around you, tempting them closer. Too close, and they risk your teeth.

Optional extra: Add a parasitic male!

We aren’t telling you to invite your ex. But Anglerfish live in the deep Ocean, so when they get the chance for romance, they don’t let it pass.

The female anglerfish is far bigger than the male, who is little more than a sperm donor with a good sense of smell.

This size difference is most on show in Kroyer’s deep-sea anglerfish, Ceratias holboelli. Males can reach up to 1.3cm (while free-swimming), while the females are on average 77cm long.

When he finds a female, he bites her and doesn’t let go. Over time, he fuses with her, receiving nourishment in exchange for sperm. One female can have multiple males attached, and she can lay her eggs at her own leisure.

To add your parasitic male, just stick an empty loo roll in a sock and staple/attach it to yourself. The more the merrier!

For the witty one-liner: the cookiecutter shark

This is a true Halloween shark, with the old nickname “demon whale-biters”.

These little sharks gouge a circle of flesh out of animals, leaving bite marks as if cut out by a cookie cutter.

Whales and dolphins are often spotted with the strange circular wounds, multiple if they were unfortunate enough to come across a group of cookiecutters. One sei whale was found with 138 “cookies” cut out. Fortunately, these bitey biscuit bois are only half a metre long, so the damage they cause is limited.

The cookiecutter doesn’t need the dentist – rather than brushing their teeth, they lose the entire bottom row and usually swallow it with whatever meal they are enjoying (recycle some of the calcium).

What you need for the shark costume

What you need for a cookiecutter shark Halloween costume. Posted by Ocean Generation. — *Cookiecutter shark photo by Blue Planet Archive/Alamy*

A cookie cutter
Cardboard/card
A black scarf
Brown clothes
Optional: Chef hat

Sometimes simplicity is the way. Wear brown clothes, hang a cookiecutter around your neck and fashion a shark fin to attach somewhere, with the cardboard.

Add the black scarf around the neck, for the cookiecutters dark collar (this is one of the reasons they are also known as ‘cigar sharks’). If you want to make it a couple’s costume, dress your partner as a whale with some bloody circles on them!

Optional extra: glowing belly!

Cookie cutters have photophores on their belly, to camouflage them from predators and prey by matching the little light that penetrates the depths.

Why not add some flair to the costume? Add some glitter to the belly, or even better some glow in the dark stickers/paint or some fairy lights.

N.B. Cookie cutters do not have a classic shark’s dorsal fin, only a small one towards the tail. The recommendation is for costume purposes only. Also, don’t take any flesh out of your partner for this costume.

For the flamboyant and fiery: the Pompeii worm

Pompei worms live around hydrothermal vents in the Ocean. Posted by Ocean Generation. — *Photo by National Science Foundation (University of Delaware College of Marine Studies)*

In the depths of the Ocean, there are huge chimneys belching out black and white smoke. Hydrothermal vents are where the Ocean meets the hot inside of our planet. Think of thermal spas with the heat turned way up. Combine the extreme heat with the crushing pressures and cold of the deep sea, it doesn’t sound like an appealing neighbourhood.

But they host rich ecosystems, full of incredible creatures adapted to these extremes. Hydrothermal vents may have been the origin of life on our planet.

The Pompeii worm shows a flamboyant distain for the usual limitations for life. Bright red, building a tube for itself to live in, it dances in water that would kill most. It can take the heat up to 55 degrees Celsius (131 Fahrenheit). But a woolly jumper of bacteria helps it stay cool, despite living in waters that can be over 100 degrees C (212 F). This is no normal jacket, as the worm has to keep it well fed with mucus in a symbiotic relationship*.

Four long, red-orange tentacles crown its head, used for breathing. Pompeii worms have the highest specific gill surface area of any marine worm and have acidic blood to encourage the oxygen to dissociate from their blood cells in their extreme environment. What other animal can work a feather boa with acid blood?

What you need for the costume

Pompeii worm Halloween costume, inspired by deep sea animals. Posted by Ocean Generation.

Grey/white/black trousers or skirt
Red/white long sleeve top – preferably fuzzy
Red/pink/orange pipe cleaners/paper/feather boa

Be bold. Channel your inner Pompeii worm and dance in and out of your sulfur-and-protein based tube. A fluffy or fuzzy top will show off your bacterial biofilm and use some pipe cleaners or paper to make some tentacles around your head. Smaller feeding tentacles to add a bit extra.

For the dancers: Hoff or yeti crab Halloween costume

Hoff and yeti crabs grow their own food in the deep sea. Posted by Ocean Generation, leaders in Ocean education. — *Hoff crab: University of Portsmouth / Yeti crab: A. Fifis, Ifremer/ChEss, Census of Marine Life*

Another resident of the hydrothermal vents are crabs. There are two we want to spotlight. The Hoff and Yeti crabs.

Both are named after their appearance. One has a hairy chest and so bears the name of Baywatch legend David Hasslehoff. The yeti crab is the more general term for the Kiwa genus, of which the Hoff crab is a member.

These downy decapods are covered hairs. What is the other key to their success in the deep? Dancing.

The crabs wiggle and wave, which moves water over the hairs, feeding the colonies of bacteria that live there. These crabs grow their own food in their fur, so the fuzzier the better.

What you need for the crab costume

Fuzz – for the Hoff, a hairy chest, and for a Yeti crab, get your arms fuzzy
Creative claws
Snacks in a pocket

The key for the crabs is owning your hair and rewarding your dancing. Every wiggle is a snack earner. Get fuzzy, and for added authenticity get some snacks in the fuzz for easy snacking.

For the dramatic introvert: the vampire squid

Vampire squids thrive in oxygen minimum zones in the deep Ocean. Posted by Ocean Generation. — *Photo by Monterey Bay Aquarium*

As another unfairly named creature, the Latin name of the vampire squid, Vampyroteuthis infernalis, literally means vampire squid from hell.

Red eyes, black or red colouration, and spikes lining their arms (incorrectly known as tentacles), living in the abyssal depths of the Ocean. You can see what they were going for.

Truly a survivor, these cephalopods live between 600m and 900m and can thrive where others can’t – oxygen minimum zones. These parts of the Ocean don’t have enough oxygen for most organisms to breathe. The vampire squid can survive where oxygen saturation is as low as 3% (the usual oxygen saturation in air is 21%).

If something does dare to get in their personal space, the vampire squid has a lesson for all of us: when stressed, be a pineapple.

The vampire squid will ‘invert’ itself, pulling its arms over its head, covering its photophores and revealing the spiny projections (known as cirri) underneath.

The glowing tips of its arms are held far above the head to draw attacks away from where they could do serious damage. The arm tips can grow back, so can be a handy (if you’ll pardon the pun) distraction.

What you need for the squid costume

What you need for the vampire squid Halloween costume. Posted by Ocean Generation. — *Vampire squid photo by Monterey Bay Aquarium*

Loose black or red clothing, ideally a cape
Cardboard to make some spines
Lights/sparkles
Fins on the side of the head
Red eyes

To embody the vampire squid, you need your own space. Space to let your cloak free. Line the inside with your cirri (the spines), in case of encroachment by unwanted parties. Coloured contacts or red eye makeup to give that squid from hell look.

Have fun with your lights on this one – vampire squid can control their own light show. Lights over the cloak and in your hands can make an entrancing look, ready to be muffled and switched to a spiny dark outer should the mood change.

Optional extra: Glitter juice

If the pineapple pose doesn’t work, a vampire squid has a secret weapon. A sticky cloud of bioluminescent mucus, which they can squirt at offending parties. This glowing goo can dazzle while the vampire squid escapes or stick to the transgressor and light them up for up to 10 minutes. Ten minutes is a long time to wait to see what else can see you in the dark Ocean.

A spray bottle, with some (eco-friendly) glitter mixed with water will give you your last line of defence.

*Grime, J. P., & Pierce, S. (2012). The evolutionary strategies that shape ecosystems. Wiley-Blackwell.

Post by

Will Steen

The oldest things in the Ocean: Explained.

Monthly: Impact in your inbox.

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