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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Will Steen

The Hidden Price of Feeding Langkawi’s Eagles

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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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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 Hidden Price of Feeding Langkawi’s Eagles

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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 Hidden Price of Feeding Langkawi’s Eagles

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30. 05. 2025 Will Steen

Can we rebuild coral reefs? The promising (and weird) world of coral reef restoration

Can we rebuild coral reefs? Posted by Ocean Generation.

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Here’s what you need to know about coral reef restoration:

Corals are cool. But the reefs face danger. A warming Ocean causes corals to bleach more regularly. Some estimates say we have already lost 50% of the world’s coral reefs.

While we work to reduce the emissions of greenhouse gases, to keep our world from warming, we can also look to support the recovery and rebuilding of impacted coral reef systems. So today we ask: how can we restore our coral reefs (and how is a coral reef like a struggling orchestra)?

Why should we care about coral reefs?

Anyone that has had the privilege of diving on a coral reef will tell you how special these places are.

Reefs cover less than 0.1% of our Ocean floor but support 20-30% of marine species. We have tried to estimate the economic value coral reefs bring, but it’s a difficult area, and economists can’t agree on the price tag.

The range of $30 billion to over $300 billion puts coral reef value somewhere between “tremendously valuable” to “astronomically precious”. Include the goods and services provided by coral reefs and the estimated figure is $2.7 trillion. Trillion with a T.

Coral reefs are excellent shields – healthy reefs can absorb 97% of wave energy. This protects our coasts, on which many of us live. Think of the most famous reef in the world – the Great (what?) Reef for example.

So, we have to keep our corals around. The question is: how are we going to? Let’s take a look at the three most common coral reef restoration methods.

How can we help corals survive? Posted by Ocean Generation. — *Image credits: Coral gardening photo by the BBC, Microfragmentation photo by Blue Corner Dive*

What is coral gardening?

The most used method of reef restoration is coral gardening.

Fragments of healthy coral are taken from an existing coral reef and placed in a nursery. This nursery is set up for the baby coral to thrive. When the corals reach a big enough size, they are ‘planted’ back onto the reef.

This is a very accessible, increasingly cheap way of tackling coral decline. Costs are estimated to drop from $150-$400 per coral to <$10 per coral with improving techniques. It doesn’t require expensive equipment, and is a very visible, practical way to engage communities.

Does coral gardening work long-term?

Not sure. Short-term results? Pretty promising. Two large projects (Coral Reef Foundation in Florida and CARMABI in Curaçao) claim over 80% survival after one and three years respectively.

However, it isn’t all sunshine and coral roses. These figures aren’t peer-reviewed (cross-examined by other scientists) and likely reflect best-case scenarios for certain coral species.

A more accurate long-term figure is likely 30-50%, and although it does increase coral cover, does not comprehensively improve reef health.

A healthy coral reef is diverse.

Gardening projects, however, tend to focus on fast-growing genus like Acropora, ignoring slower growing (but just as important) species. This results in ‘restored’ reefs that are low in biodiversity.

Coral gardening projects tend to focus on fast-growing species. Explained by Ocean Generation.

It’s like trying to have an orchestra with only violins. It is technically music, and possible to even be good, but lacks the depth and the magic of the interplay between instruments that brings it to life.

(One of our marine scientists favourite orchestral pieces is the Planet Earth II Suite: the layering of the song as different instruments come in make your soul soar. What other piece can boast having sleigh bells?? Listen here.)

This coral restoration method is also limited in scalability – can it be used to make a big difference?

Coral gardening is like trying to replant the Amazon by using window boxes. It’s cost effective, and great for fast-growing corals. BUT it produces reefs with low genetic diversity (making them vulnerable to disease) and low species diversity.

Gardening alone isn’t going to save our coral reefs.

Can cutting corals into tiny bits help?

Microfragmentation is chopping up coral colonies into little pieces. The fragments are placed next to each other, and will grow out, to form larger colonies.

The key advantage here is in the species this method targets, such as star or brain coral.

Where, with coral gardening, we are predominantly working with fast-growing corals, this is for the slow-growing corals that are key to reef building, and for whom other methods won’t be effective. These are the bass section in our orchestra: there are less of them, and they are slower, but still crucial to the symphony.

Studies have suggested that this method of coral restoration can accelerate the growth of massive colonies by 10-15%.

However, this is limited to massive species and carries the same dangers of limited genetic diversity as gardening, if few donor colonies are used.

As coral reproduction is strongly linked to size, smashing colonies into little bits certainly impacts their reproductive capacity in the short term. Currently, we don’t know how much or how long that effect lasts.

While this method is an excellent boost for the big boys on the reef, it’s not a reef-wide solution. If it’s used with more conventional gardening, you can help specific species of corals grow more successfully. But how can we support the entire reef system, in all its complexity and diversity?

Microfragmenttaion, a coral reef restoration method, can help slow growing corals. Posted by Ocean Generation.

How do corals reproduce?

Coral reproduction is weird. A few nights of the year, all the corals on the reef will release their eggs and sperm to mix in the Ocean currents. These are called coral spawning events.

The fertilised eggs will be Ocean floaters until they find a spot to settle. Most species settle within two weeks, but some can take as long as to 2 months.

Can we increase the amount of coral larvae settling?

There’s growing appreciation of the different ways coral larvae decides where to settle. We now know that the sounds produced by a healthy reef act as a draw for young corals (find out more about the sounds of a coral reef here). Similarly, we are now realising that young corals “smell” their way to their new home.

What can we do with this information? We can advertise reefs in a way young corals can understand. Speakers playing the noises of healthy reefs, and a newly engineered gel releasing chemical cues replicating a healthy reef are some examples.

These solutions increase coral settlement, helping the reef rebuild itself. This is like advertising for more players in the orchestra, looking to bring in new talent. But what if we take that further?

Coral spawning is fascinating. Explained by Ocean Generation, leaders in Ocean education.

How do you help corals have more babies?

The Ocean is becoming a lot less of a love nest as it warms. The success rates of coral fertilisation drop with rising temperature and acidity.

So, how can we help the corals? By collecting the eggs and sperm during spawning events and taking them back to the lab. There, they have the best chance at fertilisation, and the larvae can be reared until they are ready to settle. Then, they can be released back to the reef.

We can protect the coral at their most vulnerable stage of life.

In the wild, less than 1% of coral larvae will make it to settlement. Of those that do, up to 90% won’t survive the first few months. The proportion of larvae to survive to a juvenile coral is minute, somewhere between 0.001 – 0.1%.

Through assisted reproduction, the success rates are still low, but much higher than the wild. Some studies have shown survival rates to a year to be 0.1-1%. That might seem small, but it’s at least ten times better than the chances for a wild coral larvae. Others show an increase in coral cover after nearly three years. Even more promising? Drop the young corals in, rather than manually fixing them to the reef (a seeding approach), survival rates after a year can reach a whopping 9.6% while the costs remain low.

Here’s the real magic: these methods keep the gene pool diverse and interesting.

Coral reef restoration methods. Explained by Ocean Generation.

We’ve already discussed fragment-growing methods like coral gardening and micro-fragmentation. But unlike fragment growing (which is basically coral cloning), assisted reproduction gives us reefs with genetic variety – think coral cousins rather than identical twins. And that variety? It makes reefs more resilient long term.

This would be the equivalent of sponsoring a musical training programme, nurturing the next generation to guarantee the success of our orchestra.

Where’s the catch?

All the data here comes from projects with scientists doting on every need of the corals. Basically: If we were to strip back the money and the monitoring, the survival rates of corals will probably take a hit.

Assisted reproduction works with the natural reefs, which is its strength as it maintains diversity and avoids the risks of disrupting the ecosystem with new species. It’s also a weakness, as some reefs have lost too many sexually mature corals to rebuild themselves.

While it may not be the most efficient way to resurrect a reef, assisted reproduction could make the difference on degraded reefs needing a boost.

Are artificial reefs the answer?

Like corals, people are great builders. Like us, corals need a good foundation to build on. Some of the most fun coral reef projects focus around providing those foundations, through concrete blocks and 3D printed units.

These foundations can encourage our polyp pals (AKA: coral babies) to settle down and make their home. We can build a new concert hall for our orchestra.

These structures provide habitat immediately for non-coral animals to use as well (little fishies can hide and sponges and algae can grow).

We have also found that running electricity through a concrete foundation helps coral growth (now that’s current science).

Artificial coral reefs are a good initial boost.

Plus, it works quickly and can be scaled up easily. Like coral gardening, artificial reef building is accessible enough for local communities to get their hands wet. And there’s nothing like a concrete reef structure to make conservation visible *literally* and raise the profile of reef protection efforts.

Artificial coral reefs are a reef restoration method. Posted by Ocean Generation.

But we don’t have a silver bullet here. There is concern that they could act as an ‘ecological trap’. They are fish magnets, not factories – they concentrate, not create.

Natural reefs and their residents settle and thrive not just because of a hard surface, but because there are good water conditions, plenty of food for their inhabitants and their populations are balanced.

A reef in a poor location could end up negatively impacting the local fish. Imagine a new housing estate, but with no water and no shops. And acid rain. And bears. This is not a good housing estate.

For artificial coral reefs to work they must be designed AND located with care and understanding. Don’t build a concert hall with terrible acoustics, no electricity and no public transport links. You need to know the area you are building in.

Can we make super corals to survive climate change?

None of the approaches so far tackle the root issue. The main threat to coral reefs is that the Ocean is changing faster than they can cope with.

Could the answer then lie in us accelerating their adaption, selecting the more heat-resistant corals as evolution does, but faster?

Our orchestra can experiment with new instruments and compositions to make a new sound.

What is a super coral?

Through selective breeding (choosing corals that can take the heat and breeding them) and microbial manipulation (like giving corals a probiotic yogurt, with beneficial bacteria and other tiny friends), we may be able to create ‘super corals’.

When it works, it works brilliantly. Some lab studies showed that selectively bred corals could handle Ocean temperatures 1.5 degrees warmer than their non-selected colleagues.

It’s an approach that directly addresses the main threat to corals, temperature rise, and could produce corals able to thrive in the predicted conditions of the Ocean in 2100.

But temperature isn’t the only thing at work. These super corals have shown decreased resistance to Ocean acidification, the co-conspirator to Ocean warming. Think of a triathlete that can swim *like a fish* but also cycles like one. One-trick ponies aren’t what we’re going for when it comes to building healthy coral reefs.

Our high performer corals also put a lot of energy into being super, so have less to put into growth and reproduction.

What are super corals? Explained by Ocean Generation.

Another simple hesitation is the amount we don’t know. How could the super corals fit in? Will they outcompete naturally evolving corals? Disrupt ecological balances we don’t yet understand? Will our new music find an audience?

Despite these challenges, assisted evolution remains a promising way for reef conservation in a rapidly warming world.

As one researcher memorably put it: “We’re not playing God with corals; we’re simply giving evolution a helping hand when we’ve rather inconsiderately moved the finish line.”

But if we are making new music, maybe we need a different orchestra set up.

Is coral reef restoration the way to go to save reefs?

New approaches and ways of thinking suggest that we should embrace our changing world.

We may not be able to ‘restore’ our reefs to the way they were, as our world is not the same as it was. Instead of spending time, money, and effort trying to build the reefs that used to exist, we could help build a reef that can thrive in the future conditions of the Ocean.

To play to the tune of the future, maybe we need more woodwind and brass. Think more jazz improvisation than classical recital.

This could offer a more pragmatic approach, acknowledging that full restoration is not feasible in the long term. It focuses on ecosystem function rather than maintaining the old reefs and could integrate the use of ‘super corals’.

But this comes with the issues of the unknown.

Ecosystems are notorious for their chain reactions. Tweak one thing, and something you thought completely unrelated is affected. Bring wolves back to Yellowstone? Suddenly the rivers change course. Remove tiger sharks from an area? Watch the dugongs reduce the seagrass to mud flats since they don’t have to watch their backs.

How would the new ecosystem function and effect the life around it? What if the new saxophonist doesn’t get on well with the trombone players? What if the audience don’t like it?

Coral reefs support 25-30% of marine species.

So how are we doing with coral reef restoration?

One estimate calculates that less than 0.1% of degraded reef area is under active restoration. Most projects are small-scale (100m²or less) and short-term, with monitoring lasting less than 18 months.

Restoring just 10% of degraded reefs could cost billions.

The reality is most restoration projects are in convenient places, not where the corals will thrive. This renders most restoration projects vulnerable. Some can be completely lost after promising growth.

But reef restoration is a stark reminder – humanity can act.

Coral bleaching is among the most visual representations of our changing climate. But the time, effort and care that is devoted to restoring coral reefs around the world shows the desire to protect our natural world.

For us to have healthy coral reefs, to have our orchestra really sing, we need to combine approaches. We can’t focus only on strings or on bringing in the young talent. We need to support the whole orchestra so we can enjoy the music.

As corals have been a poster child for the degradation of our world, so too could they be the success story. Every young coral nurtured today could be the foundation of a healthy future reef, different to yesterday’s maybe, but no less important for our blue planet.

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Will Steen

The Hidden Price of Feeding Langkawi’s Eagles

Monthly: Impact in your inbox.

14. 05. 2025 Will Steen

What is coral bleaching?

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What you need to know about coral bleaching:

White branches reaching out, stark against the blue. Where there was colour, now only ghostly white. This haunting transformation isn’t just a visual tragedy – it’s the silent SOS of some our Ocean’s most spectacular ecosystems. This is coral bleaching.

Coral reefs aren’t just beautiful — they’re nurseries for fish, protect coasts from storms, and feed millions of people. When coral reefs bleach, their whole ecosystem is at risk. But what is coral bleaching? What causes it, and why does it damage reefs?

Are corals animals, plants or rocks?

Corals are animals. Some may have stone skeletons and live with plants. But all corals are animals.

Corals are tiny animals called polyps. Each polyp has a soft body and a mouth surrounded by tentacles, like a little sea anemone or an upside-down jellyfish. All these animals are related – they are cnidarians (silent c), named after their cnidocytes – special cells that can sting.

Where does coral’s colour come from?

Corals are incredible animals. They build immense structures that provide homes for marine species, protect the coast and create oases in the ‘desert’ of tropical seas (there are very few nutrients in the waters of the tropical Ocean).

To be able to do all this, they need some help. Corals have symbiotic algae called zooxanthellae living in their skin cells. Think of zooxanthellae as tiny solar-powered chefs living inside coral homes.

They catch sunlight, cook up energy, and share over 80% of the meal with their coral landlords. The coral provides protection and prime real estate with an Ocean view. It’s a win-win (this is what symbiotic means) – until climate change cranks up the thermostat.

It’s zooxanthellae that gives coral its colour. The magical, vivid world of coral reefs is painted by these little algae. Without them, corals are translucent, and the white of their calcium carbonate skeleton shines through.

Why do corals bleach?

The happy relationship between coral and zooxanthellae can be disrupted. When it is, this can lead to the expulsion of the algae from coral tissues, leaving the coral gleaming white (it is a spectrum, coral can partially bleach).

The most common cause of coral bleaching is thermal stress AKA temperature. If conditions aren’t right, the systems that make photosynthesis (plants turning sunlight into food) can break.

When these systems break, they can produce reactive oxygen species (ROS). ROS are produced in normal function, but too many ROS harm the coral. When the coral detects this build up, it acts in self-defence and throws the algae out.

Usually, this is from it being too hot, but the system can be broken when it is too cold, or in too much sunlight, or exposed to harmful pollutants.

That’s a bit abstract. Let’s make an analogy.

Imagine the coral as a battery, and the algae as a solar panel. Normally, the algae are providing energy to the battery from the sunlight. But if the solar panel gets too hot or is exposed to too much sunlight under a magnifying glass, it might start to malfunction. It starts to spark, so to protect itself the battery disconnects. Without its solar panels, our coral battery can only run on emergency power for so long before it’s completely drained.

Why does coral bleaching happen? Explained by Ocean Generation.

History of coral bleaching – how long has bleaching been about?

We’ve known about coral bleaching for nearly a century. In 1929, scientists first described it during extreme low tides. But it wasn’t until 1984 that a mass bleaching was documented, linked to unusually warm waters.

Then came 1998 — the first global mass bleaching event, when around 16% of the world’s coral reefs were lost.

Places like the Maldives, Seychelles, and reefs in the Indian Ocean lost nearly half their coral cover. 2023 saw the start of the fourth global coral bleaching event, that over the next two years saw an estimated 84% of the worlds coral reef areas bleached.

Sounds bad, but this isn’t the end.

Why do corals bleach? — *Image credit: Great Barrier Reef Foundation*

Does bleaching mean coral is dead?

No. A bleached coral is still alive, it just doesn’t have its friend feeding it. This leaves the coral more vulnerable to disease, but also to starvation. Unless our battery reconnects to its solar panel, it will eventually run flat.

Having repeated bleaching events reduces corals’ ability to recover. It’s like punching them while they are down.

When the coral eventually dies, it loses its white look and will begin to get covered with other algae and seaweed.

However, corals have shown us again and again they have an amazing ability to recover when given the chance.

Different species of coral are more tolerant, and different species of zooxanthellae can take more heat too.

Some species of coral bounce back faster than others; the marine equivalent of those friends who somehow recover from a night out while you’re still nursing a headache. The massive boulder corals? They’re the slow-but-steady marathon runners. The branching corals? More like sprinters – quick to bleach, but sometimes quicker to recover.

After bleaching, it is possible that coral acquire more heat-tolerant photosynthesising friends, chefs that can take the heat in the kitchen. Corals aren’t going down without a fight.

How can we help prevent coral bleaching? Explained by Ocean Generation, leaders of Ocean education.

How can we help the corals?

There is a lot of work going into understanding corals, and reef restoration methods continue to be tested and implemented (read here for more.)

Corals are the poster child of Ocean health. They are impacted by all our Ocean threats, which means you can help wherever you are.

Every time you switch off an unnecessary light, choose a reef-safe sunscreen (free from oxybenzone, octocrylene or octinoxate), or select a sustainably caught fish dinner, you’re casting a vote for coral survival.

The future of coral reefs could be written in bleached white, or in vibrant technicolour. The pen, rather excitingly, is in your hands.

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Will Steen

The Hidden Price of Feeding Langkawi’s Eagles

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26. 03. 2025 Will Steen

What is the water cycle?

Why there is no water cycle without the Ocean.

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Our planet is known as the blue planet, over 70% of it is covered in water, most of which is the Ocean.

This water shapes our landscapes, influences where life thrives, affects the health of our Ocean and the weather in our skies.

The Ocean is always closer than you may think (not in a sinister, about-to-jump-out-at-you way. It’s more of a realising-it-is-Thursday-and-the-weekend-is-only-round-the-corner-kind-of-way).

Take a moment, think: what is different from the water you drank this morning (if you haven’t had any, this is your reminder to drink some) and the water lapping up a warm tropical beach? Every drop of water, from what’s come out of your tap to the water five kilometres deep in the middle of the Pacific, is connected.

It is all just at different points in the water cycle.

How does the water cycle work?

There are four processes that drive the water cycle: evaporation, transpiration, condensation and precipitation.

Water is warmed and evaporates, becoming water vapour. Amongst the many good things plants do, they release water into the atmosphere through transpiration. These two processes are responsible for putting water vapour in our air, our atmosphere.

Water vapour is invisible.

The steam we see when we boil the kettle (or the clouds in the sky) is water becoming liquid again, on contact with the cooler air. That is condensation, the transition back from gas to liquid. When enough of this cloud cools and turns to water, it will clump together and fall as precipitation (snow, hail and rain).

How is the Ocean connected to the water cycle?

This water then starts its journey back to the centrepiece of the cycle: the Ocean.

The Ocean holds 97% of the Earth’s water – approximately 1.34 billion cubic kilometres. 86% of evaporation is from the Ocean, and 78% of precipitation re-enters the Ocean, directly. You can’t have the water cycle without the Ocean.

Ice holds 2% of global water and just 0.001% is in the atmosphere – that is all the clouds in the sky.

But if we add all that up, there’s a little still on the table – or more accurately, on land. That is the groundwater, lakes, swamps and the rivers. Rivers make up only 0.0002% of the total water on Earth.

The Ocean holds 97 percent of water. Posted by Ocean Generation, leaders of Ocean education.

What does the water cycle do? Why is it important?

There are five main points of importance for the water cycle:

1. Regulating Climate:
The water cycle helps distribute heat around the globe, influencing weather patterns and climate conditions. It absorbs and releases energy during evaporation and condensation, which affects temperature and weather.

2. Sustaining Ecosystems:
The water cycle provides the water necessary for plant growth and supports all forms of life by delivering freshwater to ecosystems through precipitation.

3. Shaping Landscapes:
The water cycle contributes to erosion and sedimentation, reshaping geological features over time.

4. Circulating Minerals and Nutrients:
Water transports minerals across the globe, enriching sea and soil and supporting plant life.

5. Maintaining Freshwater Supplies:
The cycle replenishes freshwater sources, such as rivers and lakes, which are essential for human consumption and agriculture.

Imagine a world without a water cycle – what would it look like?

Why is the water cycle important? Explained by Ocean Generation.

How is the water cycle changing?

Human activity is interfering with the hydraulic cycle at every stage.

Deforestation means less trees to transpire and absorb rainfall. Urbanisation interrupts drainage and can increase surface runoff. When it rains, the water that would have been absorbed by the ground now hits tarmac and runs down the road.

The single greatest threat to the water cycle, and therefore to all life on Earth, is climate change.

How is climate change impacting the water cycle?

Climate change is intensifying the hydraulic cycle. Higher temperatures lead to more evaporation, more water vapour in the atmosphere, which results in more intense storms and rainfall. At the same time, droughts are becoming harder to predict and more severe.

These changes directly threaten our lives.

Water related events from 2024 — *2024 Summary Report – Global Water Monitor*

Water is the life blood of our planet, and the water cycle is the pulse that keeps it alive.

The hydraulic cycle regulates our climate, fertilises and maintains our ecosystems and shapes our world. We are changing it through our actions and activities.

Understanding this cycle is the first step, but acting to protect it is the most important. The question is: what will we do to safeguard the blue heart of our planet?

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Will Steen

The Hidden Price of Feeding Langkawi’s Eagles

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16. 10. 2024 Thi Nguyen

How Climate Change threatens polar species: Polar bears, Orcas and Narwhals

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Many polar species depend on sea ice for essential activities like resting, hunting, and avoiding predators but climate change poses a threat.

Polar species have finely tuned their behaviours, and physiological traits to the seasonal advance and retreat of sea ice.

However, as sea temperatures rise and the Arctic (in the Northern Hemisphere) warms at four times the global average rate, sea ice is shrinking and breaking up earlier each year.

This trend presents growing challenges for polar species that rely on ice, highlighting just how important it is to tackle climate change to ensure their survival.

How polar bears are impacted by climate change

Characterised by their large size, dense white fur, and flattened cranium, polar bears are apex predators in the Arctic ecosystem. Their primary prey are ice-dependent seals, particularly ringed and bearded seals.

Seals use the ice as a platform for resting, breeding, and giving birth. Using an ambush technique, polar bears wait at seal breathing holes, catching seals as they come up for air. This saves them energy compared to more active hunting methods.

Ringed and bearded seals in the Arctic, posted by Ocean Generation

Polar bears’ hunting success peaks in the spring and early summer, coinciding with the weaning period of seal pups. This makes it a critical time for the bears to build fat reserves essential for survival through winter.

Climate change delays sea ice formation in autumn, and it’s reducing the time available for hunting seals later in the year. As a result, it’s becoming increasingly difficult for polar bears to build or maintain their fat reserves.

Increased fragmentation of sea ice also forces polar bears to swim longer distances to reach stable ice. In some regions, polar bears have been recorded swimming over 50km. This is an energy draining task for these not-so efficient swimmers, due to their paddling motion and the added drag of swimming at the water’s surface.

Polar bears wait at seal breathing holes

With summer sea ice disappearing, polar bears are becoming more dependent on food sources on land. These offer far less nutrition compared to the energy-rich blubber of seals and increases human-wildlife conflict.

They are currently listed as Vulnerable under the IUCN Red List (last assessed in 2015), facing threats from residential and commercial development, human disturbance and climate change.

How narwhals are impacted by climate change

Narwhals, distinguished by their long, protruding tusks, are remarkable divers capable of reaching depths of up to 1,500 meters in pursuit of prey. Their diet primarily consists of fish (Greenland halibut in particular), cephalopods (such as squid), and crustaceans.

Narwhals depend on breathing holes in the ice to survive

To support their slow, endurance swimming, narwhals have evolved a high proportion of specialised slow-twitch muscles, which make up about 90% of the muscle fibre in their bodies. These muscles are rich in myoglobin. This is an oxygen-binding protein that enhances their ability to store and use oxygen efficiently during extended dives.

Narwhals, like other marine mammals, depend on the stability of breathing holes in the ice to survive. However, climate change has made these ice conditions increasingly unpredictable, leading to entrapment and fatalities for narwhals when they can’t locate a breathing hole.

Their narrow temperature range coupled with strong attachment to specific locations and migratory routes makes them particularly vulnerable in the rapidly warming Arctic.

Currently listed as Vulnerable on the IUCN Red List (last assessed in 2023), narwhals are increasingly threatened by climate change, as well as energy production and mining activities.

How orcas are impacted by climate change

Orcas inhabit the Oceans worldwide, ranging from polar regions to tropical waters. They are categorised into three distinct forms, A, B and C, with type B exhibiting cooperative hunting behaviour in pursuit of seals. In these strategies, family group members work together to create synchronised waves that wash seals off the ice.

Orcas find new opportunities in the changing polar regions

When searching for potential prey, orcas adapt their travel behaviours to the surrounding ice conditions. In open water with minimal ice, they tend to stay close together, while in pack ice, they spread out and often travel as individuals or pairs.

Near ice floes (thin sheets of frozen seawater), individuals engage in spy-hopping to locate seals, taking multiple views from various angles around the edge of the floe.

After observing, they swim away briefly to vocalise and communicate with other group members before returning.

Before attacking, the whales swim together in loose formation, often rolling at the surface. They move side-by-side away from the ice floe before charging back rapidly in a coordinated manner, generating waves as they approach.

Depending on the size of the floe, they create two distinct wave types. One is a breaking wave for smaller floes that can wash seals directly into the water, the other is a non-breaking wave for larger floes that shatters the ice and drives seals off.

Many Arctic marine species use frozen areas as a refuge from orcas.

Bowhead whales, which can break through the sea ice to create breathing holes, face few predators besides humans and orcas. However, as sea ice shrinks, orcas are increasingly detected in Arctic waters.

Many polar species use frozen areas as a refuge from orcas, but climate change and shrinking sea ice threatens them. Posted by Ocean Generation

While this provides new prey opportunities for these apex predators, it could significantly stress prey species, potentially altering their behaviour and population sizes. For example, the specialised locomotor muscles of narwhals make them too slow to escape orcas.

Moreover, the increased presence of orcas may impact indigenous communities that rely on subsistence hunting to sustain their way of life.

Orcas are currently listed as Data Deficient under the IUCN Red List (last assessed in 2017). This highlights the need for more research to comprehensively understand population trends and conservation priorities.

Turning climate challenges into opportunities

The survival of polar species is increasingly threatened by climate change, which leads to shrinking sea ice and altered ecosystems.

These changes not only challenge the feeding and breeding behaviours of these animals but also affect indigenous communities that depend on these species for their livelihoods.

We can help through supporting conservation organisations, taking climate action, advocating for policy change, engaging in sustainable practices, and raising awareness about our impacts on polar ecosystems.

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Thi Nguyen

The Hidden Price of Feeding Langkawi’s Eagles

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11. 10. 2024 Thi Nguyen

Balancing conservation and community in polar wildlife conflicts

Balancing community and conservation in polar wildlife conflicts

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Addressing human-wildlife conflict is essential for both wildlife conservation and human well-being.

As human populations expand into natural habitats, finding solutions that promote coexistence between people and wildlife becomes increasingly important. By fostering harmony, we can support thriving species, healthy ecosystems, and positive relationships between local communities and conservation efforts.

Reducing conflicts benefits wildlife and eases financial losses for local communities. It also aligns with the UN’s Sustainable Development Goals by enhancing livelihoods, building community resilience, and creating economic opportunities for local populations.

Mitigating human-wildlife conflict on land

Climate change intensifies human-wildlife conflict by changing the historical range and behaviour of wild species, increasing the frequency of interactions between humans and wildlife.

Climate change intensifies human-wildlife conflict. Posted by Ocean Generation, leaders in Ocean education.

While addressing climate change is key to reducing these conflicts, communities can adopt strategies to minimise interactions with conflicting species. Some of these approaches are listed below:

Fencing key resources, such as livestock, and securing protected areas. Planting buffer crops could also reduce wildlife consuming important resources.
Implementing animal-safe food storage facilities and improving waste management systems can prevent wildlife from being attracted to human food sources.
Integrating guarding measures, such as specialised livestock-guarding dogs or patrol officers, into resource protection could provide early warning signs to alert residents to potential conflicting wildlife.
The use of non-lethal deterrents, such as visual, chemical, and acoustic repellents, can further discourage wildlife from approaching human settlements and resources.
Economic costs of conflicts could also be reduced through compensation schemes, alternative income generation, or increasing wildlife-related tourism.

A better understanding of animal movement can help predict high-risk areas and times, allowing for more targeted mitigation efforts. For example, researchers studying moose found that the risk of vehicle collisions increases in winter when snow depth is below 120 cm and nighttime traffic is higher due to longer nights.

This highlights the need for seasonally adaptive strategies to mitigate such risks.

Mitigating human-wildlife conflict in the Ocean

Fishers have several options to minimise encounters with marine mammals.

Ocean mammals often become entangled in fishing lines

Mammals often collide with or become entangled in vertical lines attached to buoys, which mark where nets have been set. To prevent wildlife harm and gear damage, fishers could reduce the number of vertical lines in the water column or use ropes in colours more visible to mammals.

Common rope colors like yellow, green, or blue may be difficult for whales to detect. Switching to colours such as white, black, or striped patterns could make the ropes more visible to whales, potentially helping them avoid entanglement.

Another approach involves weakening lines so that entangled animals can break free more easily. However, this solution can result in financial losses due to reduced catch and replacing lost gear.

Technological innovations, such as acoustic buoy releases that surface only when triggered, could eliminate the need for vertical lines. Another potential solution is the use of pingers, which are devices placed on lines that emit noises at specific frequencies to warn whales and other marine mammals away from boats and fishing gear.

Fisheries-have-several-options-to-minimise-encounters-with-marine-animals

While these strategies could help reduce human-wildlife conflict in fisheries, more testing is needed to see how effective they are. Supportive initiatives, like financial compensation programs to cover losses from wildlife, can ease the economic strain on fishers and encourage the use of non-lethal deterrents.

Collaboration between scientists and communities is key to solving these challenges. For example, the Alaska Longline Fishermen’s Association partnered with biologists and bioacoustic experts in 2003 to study whale behaviour and minimise interactions with longline boats. This led to the creation of the Southeast Alaska Whale Avoidance Project (SEASWAP), a successful project improving our understanding of depredation.

Balancing conservation and community needs

The key to addressing human-wildlife conflict involves recognising and valuing the diverse attitudes towards conservation that influence both the conflict and resolution.

By appreciating the different perspectives of stakeholders, conservation plans can be designed to address the needs and interests of everyone involved. Engaging meaningfully with communities is key to developing policies that are not only effective but also widely supported.

Balancing conservation and community to mitigate polar wildlife conflicts, posted by Ocean generation

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Thi Nguyen

The Hidden Price of Feeding Langkawi’s Eagles

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3. 10. 2024 Grace Cardwell

Why does the climate change?

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The Earth’s climate has changed naturally for billions of years, but human emissions are rewriting the story.

Scientists know that the Earth’s climate has always changed by itself, even before humans existed.

The climate changed in a pattern for the past 800,000 years. Every 100,000 years, the Earth entered a warm period, called an “interglacial”, lasting 15,000-20,000 years. Between these periods, ice ages called “glacials” dominated.

Changes to the climate that caused these glacials and interglacials in the past can be explained by natural forcings. These are forces that act upon Earth’s climate, causing a change in how energy flows through it e.g., greenhouse gases.

What are some natural forcings?

1. Milankovitch Cycles

Milutin Milankovitch, a mathematician, discovered three “Milankovitch” cycles.

Over the past 800,000 years, these were the dominant causes of climate variability because they affect the amount of solar heat that can reach the Earth’s surface.

Eccentricity occurs every 100,000 years, corresponding with interglacials. Sometimes Earth’s elliptical orbit is more circular, which keeps the Earth at an equal distance from the Sun. When the orbit is more elliptical, Earth’s distance from the Sun changes. When Earth is closer, the climate is warmer. 

Obliquity, Earth’s axial tilt, changes between 22.1° to 24.5° every 41,000 years. Larger angles cause warmer summers and colder winters.  

Every 19,000 – 24,000 years, Precession impacts seasonal contrasts between the hemispheres and the timing of seasons. The Earth wobbles on its axis due to the gravitational pull of the Sun and moon, changing where the North Pole points. 

Milankovitch cycles are long term changes that affect the climate — *Design by Grace Cardwell*

2. Sunspots

Every 11 years, the Sun gets spots when its magnetic field increases. The temperature is lowered in this area, influencing the amount of solar radiation warming Earth.

3. Changes in Ocean currents

Ocean currents carry heat around the Earth. When the Ocean absorbs more heat from the atmosphere, sea surface temperatures increase, and Ocean circulation patterns change. Different areas become colder or warmer. 

Because the Ocean stores a lot of heat, small changes can have massive effects on the global climate. A warmer Ocean can’t absorb as much carbon dioxide (CO₂) and will evaporate more water vapour. Both contribute to the greenhouse effect and global warming.

4. Volcanic eruptions

Volcanoes spew out sulphur dioxide and ash, which blocks solar radiation and cools the atmosphere. CO₂ released in the eruption eventually overpowers this to increase temperatures, but this is only equivalent to 1% of human emissions.

5. Meteorite and Asteroid impacts

66 million years ago, an asteroid hit the Earth on Mexico’s Yucatán Peninsula. Scientists call this the Chicxulub Impact, and it drove the extinction that killed 60% of all species, including all non-flying dinosaurs.

Lots of sulphur, soot and dust entered the atmosphere, blocking out the Sun. Temperatures plummeted 15°C, causing a 15-year winter.

Natural forcings explained by Ocean Generation.

Some climate change and emissions are unavoidable.

But natural forcings are too gradual or irregular to cause current climate change.

The Intergovernmental Panel on Climate Change (IPCC) states “the observed widespread warming of the atmosphere and Ocean, together with ice mass loss, support the conclusion that it is extremely unlikely that global climate change of the past fifty years can be explained without external forcing, and very likely that it is not due to known natural causes alone”.  

Just right or too hot?

Greenhouse gases are natural, to an extent.

Some solar radiation passes through the atmosphere, hitting the Earth. Most of this is reflected into space, but some is absorbed by greenhouse gases and re-directed back to Earth.

This keeps Earth just right (Earth is called the “Goldilocks” planet!).

People are emitting too many greenhouse gases, too quickly. Therefore, more heat is trapped in the atmosphere, leading to global warming.

Greenhouse effect explained: normal and rampant CO2 — *Credit: National Park Service*

How are people causing climate change?

“External forcings” are things we’re doing that release extra greenhouse gases.

1. Power

We burn fossil fuels like coal, oil and gas to make electricity and heat. This releases carbon dioxide and nitrous oxide to the atmosphere. Half of this electricity powers our buildings.

Globally, only about ¼ of our electricity comes from wind, solar and other renewable sources.

Some people use more power than others: the richest 1% of the global population combined account for more greenhouse gases than the poorest 50%.

2. Food and Manufacturing

To make goods like steel and plastic, fossil fuels are burnt to power factory machines and many other processes. Manufacturing is one of the largest contributors to greenhouse gas emissions worldwide.

Food production emits greenhouse gases at various stages. Livestock and rice farming releases methane, fertilisers release nitrous oxides, and carbon dioxide is released to make packaging and transport the food.

How are people causing climate change: Explained by Ocean Generation.

3. Deforestation

In places like the Amazon Rainforest, trees are cut down to make space for farming and houses. From 2003 – 2023, 54.2 million hectares of rainforest was lost there.

When trees are cut down, they release locked up carbon. With fewer trees, less CO₂ absorption can take place. Land use changes make up ¼ of greenhouse gas emissions.

4. Transport

Cars, ships and planes all burn fossil fuels such as petrol. This makes up ¼ of global energy-related CO₂emissions. This graph shows our impact on the atmosphere:

This graph shows our impact on the atmosphere.

Don’t put the blame on natural forcings.

Now we know current climate change is down to us; everyone has a responsibility to reduce their emissions. Have a look and see what you can do!

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Grace Cardwell

The Hidden Price of Feeding Langkawi’s Eagles

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30. 09. 2024 Grace Cardwell

What can Antarctic ice cores tell us about the history of our climate?

What can Antarctic ice cores tell about the history of climate

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Ice cores are the key to the ancient climate and can help us unlock the mysteries of the future.

Scientists can drill into ice sheets to obtain a cylinder of ice, called an ice core.

Ice cores are “time capsules” of the climate. Over time, annual and seasonal snow with different chemical compositions, particulates (like dust), and bubbles of air are compressed into ice.

What-can-Antarctic-ice-cores-tell-about-the-climate — *Credit: Bradley R. Markle via Eos*

Scientists are asking the core questions.

One of Antarctica’s ice cores, Dome Concordia, shows the climate record for the past 800,000 years through the Quaternary period (2.58 million years ago – present).

Annual temperatures are estimated using oxygen’s heavy (O¹⁸) and light (O¹⁶) varieties, called isotopes. When atmospheric temperatures increase, more energy is available to evaporate water containing more O¹⁸from the Ocean. This water is precipitated in Antarctica and turns to ice. Scientists can relate the isotopic ratio in an ice layer to the temperature.

Trapped air is analysed for which/how much atmospheric greenhouse gases were present annually. Scientists can estimate carbon dioxide (CO₂) and methane (CH₄)to determine the degree of global warming.

Using this data and more, scientists can piece together past climates.

Ice cores are key to ancient climate: Explained by Ocean Generation.

What’s the story, ice cores?

Ice cores tell us that the climate swings between stable bounds of warm interglacials happening every 100,000 years which last 15,000 – 20,000 years, and cold glacials (ice ages).

Ice cores show these key events:

1. 800,000 years ago in the Pleistocene, ice cores show an interglacial Earth. The glacial-interglacial pattern continued from here…

2. 430,000 years ago, the Mid-Brunhes Event marked the sudden increase in the temperature range of climate cycles.

3. The penultimate deglaciation event, seen in Antarctic ice cores extends from 132,000 -117,000 years ago.

4. From 24,000 – 17,000 years ago, the Earth was glacial, with temperatures 20°C below pre-industrial levels.

5. Deglaciation began 16,900 years ago, punctuated with tiny ice ages, called the “Bøllering-Allerød” and “Younger Dryas”, thanks to the “bi-polar seesaw” (the Northern Hemisphere cools whilst the Southern Hemisphere warms and vice versa).

6. 15,000 years ago, ice sheets began to shrink. This heating continued into the Holocene (the official period of geological time which we currently live in)

7. This interglacial’s temperature peaked between 14,500 and 14,000 years ago.

What ice cores tell us about ancient climate.

8. From 13,800 – 12,500 years ago, Antarctica experienced a Cold Reversal, where temperatures plummeted.

9. The Holocene interglacial began 11,000 years ago, with temperatures fluctuating between warm and cold again.

10. 1,000 years ago, the Medieval Warm Period allowed crops to flourish, cities to rise, and populations to more than double.

11. The Little Ice Age, from the 14^th-19^th centuries, caused Viking colonies in Greenland to fail.

12. 1750 – the Industrial Revolution began. Ignorant to environmental consequences, humans started emitting greenhouse gases.

13. Scientists mark 1800 as initiating the Anthropocene, an unofficial epoch where humans effect the climate more than natural forcings.

14. Humans have continued global warming at an unprecedented rate. Summer 2024 was the world’s warmest on record. August was the 13^th in a 14-month period where global average temperatures exceeded 1.5°C above pre-industrial levels.

Antarctic ice cores timeline of events _ Ocean Generation Download

Is the past a mirror of the future?

Levels of greenhouse gases are higher than in the past 800,000 years, with average CO2 at 419.3ppm as of 2023.

Paleoclimatology records like ice cores and marine sediments help scientists to understand past climates and estimate future climates. They can compare different emission scenarios with the past to see how future climates may respond.

The Intergovernmental Panel on Climate Change (IPCC) have estimated several trajectories.

The aggressive mitigation scenario expects CO₂ concentrations to remain at Pliocene-like concentrations (>350ppm) until 2350. It will still take 100s -1000s of years for concentrations to return to pre-industrial levels.

Under a middle-of-the-road scenario, CO₂ peaks at 550ppm, remaining above Pliocene levels for 30,000 years.

If CO₂ reaches 1000ppm, the worst-case scenario suggests concentrations will remain at Mid-Cretaceous levels for 5000 years, Eocene levels for 10,000 years, and Pliocene levels for 300,000 years. It will take 40,000 human generations for CO₂ to return to pre-industrial levels.

Are past climates mirror of future events? — *Credit: International Geographical Union*

Scientists and governments can then prepare for the extreme consequences of climate change and make net-zero emission targets.

Although the Earth has recovered in the past, the future is uncertain. What will happen to our Ocean and our species? We all have opportunities to ensure a “best-case scenario”.

Antarctic ice cores unlock the past, our actions will unlock the future.

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Grace Cardwell

The Hidden Price of Feeding Langkawi’s Eagles

Monthly: Impact in your inbox.

27. 09. 2024 Grace Cardwell

Why the Arctic is the fastest warming region on the planet

The changing Ocean climate: Why the Arctic is the fastest warming region

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A polar biome brimming with glaciers, permafrost, and sea ice. Home to countless species, but for how much longer?

The Arctic is extremely sensitive to environmental changes. The increase in global mean air temperature is linked to the excessive melting of Arctic sea ice: one of the most unambiguous indicators of climate change. Since 1978, the yearly minimum Arctic sea ice extent has decreased by ~40%.

Global warming is rapidly taking place due to our greenhouse gas (like carbon dioxide (CO₂)) emissions. Our current emission rates of ~40 Gt CO₂/year could leave the Arctic ice-free by 2050.

Our Ocean also plays a role in climate change.

Barents Sea is the hotspot of global warming: Explained by Ocean Generation

“The hotspot of global warming” – not the nickname you want!

Unfortunately, this is the nickname the Arctic’s Barents Sea is bestowed. Atlantification (the process by which the warming climate alters the marine ecosystem towards a more temperate (milder) state) is to blame.

Scientists (though they’re still not 100% sure of all processes involved) have noticed drastic changes in our Ocean where Arctic and Atlantic conditions collide.

Arctic water is colder and less salty than Atlantic water. Thawing ice releases freezing freshwater into the Ocean, keeping Arctic water buoyant. Atlantic water, being warmer and more saline, should sink beneath Arctic water, creating a salinity gradient called a halocline.

The halocline protects ice from thawing by blocking warm water from rising.

However, because atmospheric temperatures are increasing and melting the ice, and less ice is imported into the Barents Sea, freshwater supplies are dwindling. This disrupts the halocline. Surface winds stir up the Ocean, drawing Atlantic heat upwards to melt the ice.

Atlantification
and the Arctic halocline explained by Ocean Generation. — *Design by Grace Cardwell*

Throughout the 2000s, the Barents Sea experienced a 1.5°C warming of the upper 60m of its water column, with sea ice thickness decreasing by 0.62m/decade.

Plenty of fish in the sea – but are they the right ones?

Birds are indicators of a changing marine ecosystem.

After hot winters in Kongfsjord (Norway), Black Legged Kittiwake diets shifted in 2007 from Arctic cod to Atlantic capelin and, as of 2013, herring as their main meal. Whilst Kittiwakes seem to have adapted to their new diet, some species aren’t so lucky…

The most abundant sea bird in the North Atlantic, the Little Auk, should eat Arctic zooplankton.

The Little Auks decreased in fitness (the ability to survive and reproduce in a competitive environment) due to Atlantic water inflow. Chick growth rate decreased from six to five grams per day when Atlantic water inflow increased between 5-25% in Horsund (Norway).

Atlantic zooplankton are a suboptimal food source for the Little Auk because they provide less energy than Arctic zooplankton. Because there is less Arctic prey, chick parents spend time and energy foraging for it and might favour their own maintenance over their chicks.

Scientists anticipate the Arctic will have the largest species turnover globally, predicting a northward marine fish species migration of 40km/decade. Atlantic species are already outcompeting Arctic species, which could lead to extinction and changes in the food web.

Could the killer whale overthrow the polar bear, which has reigned as the top Arctic predator for over 200,000 years?

Feedback. But not the helpful kind…

In 1896, scientist Svante Arrhenius noticed that Arctic temperature changes were higher relative to lower latitudes. This is known as Arctic Amplification and has occurred for over three million years.

The main driver of this is the albedo effect. This effect is a positive feedback mechanism, where the result of the mechanism causes the mechanism to repeat itself – in a loop.

Dark objects absorb 93% of the sun’s energy. When the Arctic receives solar radiation in the spring, melting ice, darker areas are exposed amongst the ice which absorb more solar radiation. This reveals the even darker Ocean, repeating the loop.

Melt seasons are becoming longer as a warming climate leads to an earlier spring melt and exposes darker areas for longer. The Barents Sea’s ice-free season increases by 40 days per decade.

Where ice has melted, vegetation replaces tundra. Plants are darker than ice, so this furthers the albedo effect. Permafrost also melts, releasing CO₂ and methane (which has 84x the warming effect of CO₂in the first 20 years after its release), contributing to the greenhouse effect and exposing darker ground.

Since 1979, the Arctic has warmed
nearly four times faster
than the rest of the globe. Posted by Ocean Generation, leaders in Ocean education.

We are amplifying these positive feedbacks with greenhouse gas emissions. Since 1979, the Arctic has warmed nearly four times faster than the rest of the globe, with the most Arctic Amplification observed in autumn and winter.

Positive feedbacks are taking place very quickly, perhaps too quickly for negative feedbacks (like cloud cover) to balance them. Scientists are uncertain about future trajectories.

In the past, the Palaeocene-Eocene thermal maximum saw an ice-free Arctic. Is this a mirror of the future?

What can be done to slow down Arctic warming?

Local knowledge aids global governance and monitoring of organisms and landscapes.

Regional plans like Alaska’s 2017 “Climate Action for Alaska” set targets for reducing emissions.

Canada’s ArcticNet scheme distributes knowledge for policy development and adaptation strategies, helping Canadians face the challenges and opportunities of socio-economic and climate change.

The Arctic Council involves international cooperation towards marine and science research. Arctic and non-Arctic states, indigenous representatives and NGOs engage in binding agreements, for example: committing to enhance international Arctic scientific cooperation.

On a smaller scale, the Arctic Ice Project wants to spread silica beads across the ice to increase reflectivity.

But it’s clear: further global cooperation is needed. In 2015, The Paris Agreement stated that temperatures shouldn’t rise 2°C above pre-industrial levels, yet global warming is continuing.

What can we do?

Every tonne of CO₂ we emit melts three m² of Arctic sea ice in the summer.

To reduce emissions, hold yourself, your country, and the businesses who produce the goods you consume accountable. Walk instead of drive. Switch off lights. Support others fighting for the Arctic.

Don’t just leave it to the scientists. The Arctic isn’t a disappearing, far-away land. Your help, regardless of scale, is necessary for our Ocean to thrive.

Post by

Grace Cardwell

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