11. 10. 2024 Thi Nguyen

Balancing conservation and community 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

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

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9. 10. 2024 Thi Nguyen

Bearly coexisting: Human-wildlife conflict in the polar regions

Human-wildlife conflict in the polar regions: Explained by Ocean Generation

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As human populations grow, we’re getting closer to natural habitats, leading to increased interactions with wildlife.

Conflict arises when wildlife presence poses real or perceived costs to human interests or needs, like loss of livestock, crop raiding or attacks on humans.

Human-wildlife conflict can have negative impacts on wildlife and can also affect community dynamics, commodity production, and sustainable development.

Conservation biologists are increasingly concerned about human-wildlife conflict in the polar regions – the Arctic in the Northern Hemisphere and Antarctic in the Southern Hemisphere.

Why is human-wildlife conflict increasing in the polar regions?

The polar regions are characterised by low temperatures, extreme seasonality, and the seasonal advance and retreat of sea ice. Both polar regions are home to numerous endemic species, but their survival is threatened by climate change, fishing, tourism, invasive species, and pollution.

Experts are concerned about human-wildlife conflict in the polar regions. Posted by Ocean Generation.

These pressures often lead to more frequent encounters between people and wildlife, especially in the Arctic where around 4 million people live.

A recent study on protecting Antarctic biodiversity found that current conservation efforts are insufficient. It’s predicted that around 65% of land animals and land-associated seabirds could decline by 2100 if global greenhouse gas emissions continue on their >2°C trajectory. The study suggests several ways to boost conservation efforts, such as:

Improving the quality of land that has been polluted or negatively impacted by human use
Managing infrastructure
Protecting areas
Controlling non-native species and diseases

How does human-wildlife conflict appear in the polar regions?

Encounters between people and polar bears

Polar bears are an iconic Arctic species, distributed across 19 subpopulations within five countries: the United States, Canada, Greenland, Norway, and Russia. They rely on sea ice for hunting (primarily seals), breeding, and resting.

With climate change accelerating and sea ice diminishing, polar bears are forced to spend more time on land. Here finding natural food sources becomes challenging, so they often seek out human settlements for a predictable source of nutrition.

The town of Churchill, Manitoba, Canada, is famously known as the ‘polar bear capital of the world’ due to the Western Hudson Bay population that pass through the town each summer and autumn.

Polar bears often seek out human settlements for food

Between the 1940s and 1980s, these bears regularly visited a waste disposal site, feeding on scraps that caused property damage, human injuries, and malnutrition for the bears. The food waste was often insufficient in fat and contaminated with plastics, metals, and wood. 

Efforts to manage the problem included better waste management, relocating bears, temporarily housing them at a holding facility until Hudson Bay froze, or, in some cases, lethal removal.

The Government of Manitoba has since closed the dump site and established the Polar Bear Alert Program to minimise the need for lethal measures and reduce conflicts with bears.

As polar bear encounters become more frequent, the significance of this program is expected to grow.

How orcas and Arctic foxes hunting impact communities

Sometimes predators feed on animals of economic and ecological importance to people. These are depredation events (events that cause damage or destruction).

Depredation events often happen in the polar regions. Posted by Ocean Generation

Mammals in the Arctic Ocean are increasingly observed preying on fish caught by commercial and recreational fishing boats. Longline fishing, which involves the use of baited hooks on a long line, is currently the most severely affected by depredation across both hemispheres, primarily by toothed whales, such as orcas and sperm whales.

These depredation events can result in financial losses for fishers who face difficulties due to reduced catch and often face costs for repairing damaged fishing gear. These interactions can also harm wildlife through injuries or fatalities caused by entanglement with fishing gear and responses from fishers.

Orcas, otherwise known as killer whales, are frequently involved in depredation events in polar regions. It’s been suggested that their group hunting behaviour enables orcas to effectively remove fish from longlines.

These animals are highly social and live in tightly knit family groups, known as pods. Research suggests that pods which overlap geographically can communicate and share information. It’s thought that this cultural transmission is causing depredation behaviour to spread throughout western Alaska.

Depredation on land is also a concern, particularly with Arctic foxes preying on reindeer calves

In the Yamal Peninsula, traditional reindeer herding practices are central to the lives of the indigenous Nenet people of Arctic Russia. However, reindeer mortality has increased due to factors such as pasture icing (explained later), disease outbreaks, and predation by Arctic foxes.

Arctic foxes prey on reindeer calves in Arctic Russia

The population growth of arctic foxes has been fueled by the collapse of the fur trade in the 1990s, which reduced hunting pressure. Industrial expansion also provided waste for foxes to feed on, further supporting their population increase.

Climate change worsens the issue by causing abnormal weather conditions, such as freezing rain and rapid temperature fluctuations, which lead to pasture icing. This occurs when a thick layer of ice forms over grazing land, trapping vegetation and making it inaccessible to livestock and wildlife. As a result, weakened reindeer become easier prey for foxes, while more carcasses are left for scavenging.

Finding solutions for people and wildlife

Human-wildlife conflict in the polar regions presents challenges, especially with the added pressures of climate change and other stressors.

However, finding solutions that harmonise conservation goals with community needs can lead to positive outcomes for both people and wildlife. Check out our article on Balancing Conservation and Community in Polar Wildlife Conflicts for strategies to effectively manage and resolve human-wildlife conflict.

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Thi Nguyen

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

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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

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

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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 20,000 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

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

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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.

Barents Sea is the hotspot of climate change: Explained by Ocean Generation

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.

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Grace Cardwell

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

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30. 08. 2024 Olivia Jones

The impact of overfishing and what you can do about it

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Fish is one of the most important food sources on the planet with more than 3.3 billion people relying on it as an important part of their diet.

Fishing is an ancient practice first thought to emerge 40,000 years ago, and for many people, it is central to their culture and way of life.

However, with our population on the rise and the demand constantly increasing, pressure from commercial fleets is causing fishing to become a problem.

Fisheries ideally harvest the Maximum Sustainable Yield (MSY), which is the most that can be continually extracted from a population without causing it to decline.

However, more and more of our wild fish stocks are being harvested at a rate faster than the fish populations can naturally regenerate. This is known as overfishing. Advancements in modern technology have exacerbated this by allowing modern fleets to track, target and process huge amounts of seafood.

According to the 2024 FAO report, 37.7% of global fish stocks are fished at unsustainable levels.

However, a recent study of 230 fisheries has revealed that the computer models used to set catch limits often overestimate the size of fish populations. This new research suggests that 85% more fish populations have collapsed than is recognised by the FAO estimate.

This high level of uncertainty when counting fish stocks poses a greater risk of overfishing and highlights the need for extra precautions to be taken.

37.7 percent of global fish stocks are fished at unsustainable levels. Posted by Ocean Generation.

Fishing in the open Ocean

Countries are allowed to exploit Ocean regions within 200 nautical miles of their coast, called the Economic Exclusion Zone (EEZ). Beyond these areas is what’s known as the high seas: 60% of our Ocean which lies beyond national jurisdiction.

The risk of overfishing is high here, as there’s great difficulty regulating such a huge expanse of Ocean that belongs to no one.

One of the principles of the high seas is the freedom for any state to have passage and engage in fishing.

However, it’s companies that rule these regions, not countries.

The combined impact of illegal fishing, and legal fishing that fails to follow scientific advice has led to 65% of straddling (fish that migrate between the high seas and EEZs) and high seas fish stocks to become overfished and for species richness to decline.

The challenges of regulating the Ocean and fisheries lead to the damage of one of our most important resources.

Threats such as over-exploitation, destructive fishing methods, and bycatch endanger the health of our Ocean and Ocean biodiversity. Therefore, there’s an immense need for change.

We need to improve the sustainability of fisheries

How can we make the fishing industry more sustainable?

Improving the sustainability of fisheries can be done in many ways. Just to name a few: increased regulation on catches and fishing gear, more legislative protection on different areas or cooperation between nations.

One important way is to influence the market and demand sustainability, which can be achieved through consumer action.

When you step into your local market, opting for sustainable seafood helps to place pressure on suppliers and drives the industry to improve – as it all comes down to consumer demand.

So, what can I do as a consumer?

1. Check the certification.

The Marine Stewardship Council (MSC) completes an assessment of a fishing operator. They look at the sustainability of their fishing, minimisation of environmental impact and how effective their management is.

Sustainable fisheries will be awarded an MSC blue badge, which appears on the packaging of their fish in store. It’s an easy way to identify sustainably caught fish while shopping. The MSC blue label is found on more than 25,000 seafood products all over the world.

However, it’s worth noting that while the MSC blue badge is the world’s most widely used certification programme for wild fisheries, it’s not without its limitations.

An independent review by ‘On the Hook’ in 2023 argued that the certification process is insufficient as an indicator of sustainable fishing and doesn’t meet consumer and market expectations.

Nevertheless, if consumers favour MSC approved seafood whenever possible, this will encourage fisheries to improve their sustainability and meet standards – as it’s currently the best sustainability certification we have.

Opting for sustainable seafood helps the industry to improve. Posted by Ocean Generation

2. Educate yourself on your options.

Another way to direct your decision to the most Ocean-friendly option is through education.

The Marine Conservation Society has a Good Fish Guide, designed to have a traffic light system to represent the environmental impact of your food. It uses scientific advice on the species and how and where it was caught to help inform the consumer on the best possible choice. The guide can be downloaded onto a phone and therefore accessed at any time!

Similar resources such as Seafood Watch and GoodFish assess Canadian and U.S markets and Australian markets respectively, who will also help you navigate the most sustainable choices.

3. Choose your supplier.

Rather than asking consumers to make the effort, some retailers will make the choice for them, and only stock sustainably produced goods.

For example, in the UK, M&S has worked with the WWF since 2010, focusing on their supply chains and ensuring traceability and sustainability in their seafood products. Sainsbury’s won both the MSC and ASC (Aquaculture Sustainability Council) awards in 2023, celebrating their achievements in sustainable fishing and responsible aquaculture.

So, if possible, try to consider buying seafood from retailers such as these, as more hassle-free way of making more fish friendly decisions.

The management of our Ocean resources is vital in allowing them to provide for us in the future. For those who choose to, fish is a favourite, but it will taste much better for having made it to your plate in the most sustainable way, minimising the harm to our Ocean.

What can I do to make the fishing industry more sustainable: Explained by Ocean Generation

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Olivia Jones

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

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21. 08. 2024 Olivia Jones

Why do marine animals migrate: Everything you need to know

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Migration across the Ocean is such an extraordinary phenomenon that scientists today are still trying to discover how and why it’s done.

How does a turtle find the same exact beach where it hatched after an epic journey across the Ocean?
How do gray and humpback whales navigate record-breaking migrations: 14,000 miles of deep blue sea over 172 days?
Why do sardines, whales, turtles, hammerheads, great whites, manta rays and all manner of smaller creatures undertake these incredible journeys across our seas?

Why do marine animals migrate across the open Ocean?

Crossing an entire Ocean is extremely tiring. You could get lost or caught in a storm and you’re exposed to various risks along the way, so why do it?

Migration comes down to a need for a resource that an animal doesn’t have in its current environment. They’re often seasonal, long-distance movements in search of food, mates, habitat or to escape predation.

Long journeys across the Ocean come with many challenges for migrants. Posted by Ocean Generation, leaders in Ocean education

Food: One of the biggest reasons for migration.

Baleen whales, like humpbacks and gray whales, will migrate to northern latitudes during the spring and summer to feed in cold arctic waters, rich in krill and shrimp like crustacea. The long, tiresome journey from the south is made worthwhile for the feast of food that awaits them there.

Turtles also make their way north, with species like leatherbacks spotted in the waters off Canada, Alaska or Nova Scotia. Leatherbacks are some of the most highly migratory animals on Earth, the longest recorded journey being 12,744 miles from Indonesia to Oregon, USA.

Here during the summer months, there is an increasing abundance of a turtle’s favourite food: jellyfish.

But of course, the food can move too.

Fish are one of the most important sources of food on Earth, preyed upon by numerous different animals, including humans. The KwaZulu-Natal sardine run, also known as the “greatest shoal on Earth,” is a mass migration of South African sardines to the sub-tropical waters of the Indian Ocean.

Sardine run is a mass migration of South African sardines in the Ocean — *Image credit: Mark van Coller/Solent News*

Estimated to rival Africa’s wildebeest migration as being the largest biomass migration on Earth, this shoal becomes a ‘moveable feast’ for opportunistic predators like sharks, dolphins, gannets, seals and whales.

Whales also migrate to find a mate.

Whales, like humpback and gray whales, feed in cold arctic and sub-arctic waters but that’s not a suitable place to find a mate and give birth to their offspring. They could breed here but there are serious risks to the mothers and their calves with the cold water and predation by animals like orcas.

Instead they move from north to south during the winter months, giving birth to their young in shallow, warm waters such as lagoons. Popular destinations include Baja California, Mexico, Hawaii and Japan.

Frodo the humpback whale, named after the Lord of the Rings character, underwent his record-breaking adventure to find a mate from the Mariana islands to Mexico covering around 7,000 miles. Check out his journey on Happywhale.

Whales migrate thousands of miles across the Ocean. Posted by Ocean Generation — *Map of Frodo’s travels from Happywhale.com*

Humpbacks will often migrate the same routes they were guided on by their mothers. Frodo’s unusually long journey may be relic behaviour of the whaling industry, where depleted numbers require males to travel further in search of a mate.

Turtles will return to the exact same beach where they hatched to lay their eggs, known as natal homing. Most turtle species spend most of their time in the open Ocean, widely dispersed across the globe.

But how do they know where they are and where they’re going?

Turtles show remarkable navigation skills with pinpoint accuracy using a combination of external cues to calculate their position and route. When they are near the site of their hatching, turtles may use visual cues such as the incline of the beach or the smell of the water or air.

However, in deeper water turtles must resort to other methods to find their way home. Loggerhead, green and leatherback turtles have all demonstrated the use of a ‘magnetic map sense’ like other long-distance migrants such as bird and butterflies.

Along a coastline, the inclination and intensity of the magnetic field will vary, giving rise to a unique magnetic signature at a precise location. Scientists suggest that hatchlings imprint on this unique magnetic signature and use it to navigate back across the entire Ocean years later.

Sea turtles have remarkable navigation skills to migrate across the Ocean

Long journeys come with obstacles that Ocean migrants must face.

Our Ocean is becoming an increasingly treacherous place for its inhabitants, with threats from entanglement, ship strike, lack of jurisdictional protection and climate change.

As these migrants make their way along vast journeys, they tend to cross paths with one of the most dominant and widely distributed animals on Earth: people.

Many important migratory routes for whales and other surface-dwelling animals like turtles and sharks, converge with areas of heavy maritime traffic. This cross over can lead to ship strike, which is harmful if not fatal to an animal.

Species like the endangered North Atlantic Wright whale are particularly vulnerable as their habitat and migration routes are close to major ports and shipping lanes. There were 37 whales were reported injured in this region between 2010 and 2014 and that is likely to be an underestimate.

Furthermore, about 640,000 tonnes of discarded fishing gear, known as ‘ghost gear’, enters our Oceans every year, posing the major threat of entanglement.

The animals who travel the most are at higher risk of such encounters. For instance, an estimated 30,000 whales and dolphins die from entanglement each year.

Rising sea surface temperatures due to climate change may also alter where migratory species find food and push them past their heat tolerance. This could disrupt the longstanding migration patterns between feeding and breeding grounds.

Humpback whales migrate to warmer waters in the Ocean to breed

Nevertheless, there’s a push for the conservation of these migratory species and a desire to make the Ocean a safer place.

We’re constantly developing new technologies to help prevent animals from becoming entrapped in fishing gear. For example, Galvanic Timed Releases (GTRs) involve materials that disintegrate over time, opening doors or panels on the gear or allowing lines to break away.

Restrictions such as vessel speed limits and altered ship routes help avoid collisions with endangered species such as North Atlantic wright whales, as well as establishing temporary precautionary zones around recently sighted whale groups.

The migration of these marine travellers across the Ocean highway are some of the most extraordinary and treacherous journeys in the world.

Continuing to learn and understand these journeys is essential for protecting Ocean life and reducing the threat that is posed by humans.

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Olivia Jones

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9. 08. 2024 Jemma Sargeant

Re-thinking the shark stereotype

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With torpedo-shaped bodies, forked tails, and dorsal fins, sharks belong to a group known as cartilaginous fishes (meaning their skeleton is made from cartilage, not bone).

As one of the oldest evolutionary groups, the earliest fossil evidence for sharks or their ancestors’ dates to 400 – 450 million years ago.

This means that the earliest sharks may have been around before trees even existed (trees evolved around 360 million years ago).

What makes sharks unique?

Sharks are one of the most diverse groups of predators in the animal kingdom. They come in all shapes and sizes. Sharks can have huge, gaping mouths (like the basking shark), long whip-like tails (like the thresher shark) or flattened, club-like heads (like the hammerhead shark).

The largest species is the whale shark, reaching lengths of 20m. The smallest is the dwarf lanternshark which grows to just 20cm long.

It’s this diversity in shape, size, feeding mechanism and habitat that has enabled sharks to persist throughout all parts of the Ocean over millions of years. They even live in some freshwater environments.

Why are sharks important?

Sharks can play many roles in ecosystem functioning: from predators to prey, competitors, and nutrient transporters.

Some species of shark are apex predators, meaning that they’re at the top of their food chain and exert a top-down control on food webs. Others can sit further down the food chain, yet still play an important role as food for other predators and transporting energy through ecosystems.

Large scale movements and migrations of sharks also connect even the most widely spaced food webs, transporting nutrients across the open Ocean system.

Unfortunately, sharks are heavily misunderstood.

Media and popular culture often demonise sharks, portraying them as senseless killers through sensationalistic headlines and striking imagery. This is designed to incite fear, leading us to believe that the threat posed by sharks is greater than it really is.

Did you know? Our fear of sharks originates from the ‘Jaws Effect’. It’s the powerful influence of the famous 1975 Hollywood thriller on our human perception of risk from sharks.

Put simply: Few animals are feared more than the shark.

Some sharks are at the top of the food chain

But in reality, sharks have much more to fear from us than we do them.

The probability of a shark biting a human is very low compared to many other risks that people face in their everyday lives. According to the International Shark Attack File, there were 69 unprovoked shark bites, including 10 unprovoked shark-related deaths globally in 2023.

To put this into perspective, on average, 500 people are killed by elephants each year.

Sharks don’t actively hunt humans. The most common shark incident is known as a ‘test bite’. It means sharks swim away after a single bite once they realise it’s not their preferred prey. Surfers and other board sports make up 42% of reported incidents, as the shape of their boards can bear a resemblance to seals and other prey from below.

When we do encounter sharks, it’s often because their natural behaviour clashes with our activities, from fishing to recreation.

In contrast, the global population of sharks and rays have plummeted by over 70% over the past 50 years.

The pressure on shark populations continues to rise. At least 80 million sharks are killed each year and over 1/3 of all shark and ray species now threatened with extinction.

To put that into perspective, there are only 19 countries in the world whose population is greater than 80 million. As of 2024, the number of sharks killed each year exceeds the total population of Thailand (71.8 million), the UK (68.3 million), and France (68.1 million).

Sharks are particularly vulnerable to overexploitation.

They grow slowly and take a long time to reach sexual maturity.

Shark mothers put a significant amount of energy and time into the development and care of their offspring. They also take extensive rest periods between pregnancies.

This makes sharks far less resilient and slower to recover from disturbance and overexploitation than other fish species.

Overfishing is the greatest threat to shark populations worldwide.

The 70% decline in shark and ray populations is largely attributed to an 18-fold increase in fishing pressure over the past 50 years.

A key incentive for shark fishing is the Shark Fin Trade. This is the practice of removing the fins from a captured shark and discarding the rest back into the Ocean. Shark fins have become one of the most valuable seafood products worldwide, and this globalised market exists largely to meet the demand for the traditional dish: shark fin soup.

However, despite widespread legislation designed to prevent shark finning in recent years, fishing pressure and shark mortality continues to rise.

Sharks are vulnerable to overfishing. Posted by Ocean Generation: We're rethinking the shark stereotype

Restrictions surrounding the practice of shark finning has driven up the appetite for shark meat. It’s because it’s often only illegal to land fins with the shark removed, not the whole animal. As a result, largely unregulated fisheries in the high seas continue to put pressure on global shark species.

These markets are muddied by misidentification (often of protected or endangered species). For example, in Brazil, the meat is labelled “cação”: an umbrella term under which both shark and ray meat are sold.

This lack of transparency leads to consumers being poorly informed, and they often aren’t aware that the animals on their dinner plate are at risk of extinction.

Scientists used satellite tracking to discover that about 24% of the area sharks use each month overlap with large-scale industrial fishing zones. This means that many shark species in the open Ocean spend almost ¼ of their time under the looming shadow of large-scale fishing fleets.

Climate change compounds these threats.

The Ocean’s oxygen minimum zones (naturally occurring areas of open Ocean low in oxygen) have expanded horizontally and vertically. This is due to higher temperatures and changing circulation patterns associated with climate change.

The expansion of these oxygen minimum zones has caused the habitat of oceanic sharks to be compressed towards the surface, since they can’t survive in low oxygen conditions.

Species like the blue shark are being pushed closer towards intense surface fisheries as a result, making them more vulnerable to being caught as bycatch.

Sharks diversity has enabled them to persist through millions of years. Posted by Ocean Generation: We're rethinking the shark stereotype

Despite the alarming statistics, it’s not all bad news for sharks.

In the northwest Atlantic, the white shark appears to be recovering after a 70% decline over the past 50 years, and hammerhead shark populations are also rebuilding here. This success is owed to strictly enforced fishing bans and quotas throughout their range.

This gives us hope that the successful implementation and enforcement of science-backed management across a species range can reverse shark population declines.

To protect sharks, we need to change the way we think about them.

Our irrational fear of sharks is limiting support for their conservation.

When we portray sharks in a negative light, our sense of risk becomes heightened. This leads people to believe that extreme mitigation measures such as culling are not only appropriate, but necessary.

This fear also diverts our attention away from the species which are at the highest risk of extinction and ignores the ongoing threats to sharks and their habitats.

Sharks have survived all five previous mass extinction events. For them to survive the sixth, we must re-evaluate our perceptions of them and show our support for the conservation of these magnificent creatures.

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Jemma Sargeant

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1. 07. 2024 Jemma Sargeant

How can we protect and restore our coastlines?

Protecting and restoring coastlines starts with us.

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Coastlines are the gateway to the Ocean.

Vital ecosystems like mangrove forests, seagrass meadows, coral reefs and tidal marshes exist almost exclusively in coastal regions.

They support a high biodiversity of life and provide key nursery and breeding areas for migratory species.

They’re also essential to the livelihoods of coastal populations, and we all rely on the important services they provide, such as carbon sequestration and protecting the coast from erosion.

Our coastlines are under threat.

If you’re wondering which of the five key Ocean threats impact our coastlines, the answer is all of them.

Because coastlines are the boundary between land and sea, our impacts are often amplified in coastal regions due to their proximity to the cause…us.

With more than one third (2.75 billion) of the world’s population living within 100km of the coast, it’s no surprise that coastal regions are heavily concentrated.

To supply the needs of this ever-growing population, coastal infrastructure development happens through:

Coastal and marine land reclamation, the process by which parts of the Ocean are formed into land.

Infrastructure development for tourism, such as resorts and recreational facilities.

Development of ports, harbours, and their management.

Coastal infrastructure development, posted by Ocean Generation.

This is a key driver for habitat destruction (when a natural habitat can no longer support the species present) and biodiversity loss. It also increases the vulnerability of coastal communities to climate change impacts.

With higher frequencies of natural events like cyclones and hurricanes, risk of erosion, saltwater intrusion, flooding and other cascading climate change impacts, coastal regions have never been this vulnerable.

How can we protect and restore our coastlines?

Enter: Nature Based Solutions (NBS). These are described by the IUCN as:

‘Actions to protect, sustainably use, manage and restore natural or modified ecosystems, which address societal challenges (such as climate change, food and water security) effectively and adaptively, while simultaneously providing human-wellbeing and biodiversity benefits.’

In other words, when we protect and restore natural ecosystems, we provide a whole host of benefits to ourselves, too.

This can be done by restoring degraded ecosystems to their former glory and halting further loss of existing ecosystems.

When we restore natural habitats we protect ourselves too.

Ocean Solution: Habitat restoration.

Habitat restoration is the process of actively repairing and regenerating damaged ecosystems.

Restoring coastal ecosystems such as mangrove forests, coral reefs, oyster beds and seagrass meadows allow us to address environmental challenges (such as biodiversity loss). It reduces risks to vulnerable communities (like flooding, erosion, and freshwater supply). It also contributes to sustainable livelihoods by providing job opportunities.

That’s why at Ocean Generation, we support a mangrove restoration project in Madagascar, led by Eden Reforestation.

In 2022 alone, this project contributed to:

Carbon sequestration and habitat restoration by planting over 4.3 million young mangrove trees.
Creating sustainable livelihoods by employing around 70 people per month at the Maroalika site, with a total of 1,468 working days generated over the year.

PSA: We plant a mangrove for every new follower on Instagram and newsletter subscriber. Sign up to our newsletter or follow us on our socials to be part of the change today.

Interest in nature based solutions have surged lately. Posted by Ocean Generation, leaders in Ocean education.

Ocean solution: Marine Protected Areas.

To halt ecosystem destruction and prevent further habitat loss, we must take measures to protect remaining coastal ecosystems.

One mechanism to achieve this is by implementing Marine Protected Areas (MPAs). These are designated areas of the Ocean established with strict regulations to protect habitats, species and essential processes within them.

If implemented and monitored effectively, Marine Protected Areas can provide a range of benefits across biodiversity conservation, food provisioning and carbon storage

What is the 30 by 30 target?

In recognition of the importance of healthy and thriving ecosystems, the Global Biodiversity Framework have established a “30×30” target. This calls for the conservation of 30% of the earth’s land and sea through the establishment of protected areas by 2030.

The Global Biodiversity Framework calls for 30 percent of the sea to be protected.

Spoiler alert: We’re not on track to meet this goal.

According to the Marine Protection Atlas (2024), only around 8% of the global Ocean area has been designated or proposed for MPAs, and only 2.9% of the Ocean is in fully or highly protected zones.

Research also shows that 90% of the top 10% priority areas for biodiversity conservation are contained within coastal zones (within 200-miles of the shore). We must ramp up our efforts to preserve these vital coastal ecosystems and ensure that MPAs continue to benefit both people and planet.

What are the main challenges to implementation?

Over the past 10 years, interest in the potential of Nature Based Solutions to help meet global climate change and biodiversity goals has surged, as we have begun to truly appreciate the importance of natural ecosystems.

Despite this knowledge and an abundance of opportunities for implementation worldwide, marine and coastal regions still lack uptake.

We must address the barriers to implementation to accelerate the rate of success of coastal protection worldwide, including (but not limited to):

Conflict of interest between stakeholders i.e. blocking of protective legislation by fishing and other extractive industries.
Marine and coastal ecosystems are ‘out-of-sight, out-of-mind’. This results in a lack of public and policy awareness of their value. As a result, Nature Based Solutions are often overlooked in favour of grey infrastructure such as seawalls.

Increasing our understanding of the vital services provided by coastal ecosystems is critical to overcoming these barriers.

The more we appreciate what these incredible ecosystems do for us, the more likely we are to succeed in protecting and restoring our coastlines.

Restoring coastal ecosystems help address environmental challenges

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Jemma Sargeant

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28. 06. 2024 Jemma Sargeant

Surviving in the Intertidal Zone: The gateway to the Ocean

The intertidal zone is the gateway to the Ocean

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The intertidal zone is the dynamic interface between land and sea, which is constantly shifting and changing with the tide.

This extreme ecosystem is divided into four vertical zones, based on the amount of time each section is submerged. There are the low tide zone, middle tide zone, high tide zone and splash/spray zone.

The intertidal ecosystem in the Ocean is divided into four zones — *Image credit: Science Learning Hub*

Anything that lives in the intertidal zone must withstand dramatic changes in moisture, temperature, salinity, and wave action.

Marine life and ecosystems respond to these challenges either by short-term, reversible adjustments (phenotypic plasticity), or by long-term adaptations that involve heritable genetic changes (evolution).

Let’s explore the challenges of living in this dynamic environment, and some of the ingenious ways that intertidal animals have adapted to survive here.

Intertidal animals are exposed to air for a large portion of their lives

The drying out effect of air exposure poses a challenge for these animals, and they must find ways to reduce water loss to survive here.

The most common adaptation is to avoid water loss altogether. Intertidal molluscs (like mussels and oysters) retain water within their shells and tightly seal them shut. Others seal off their shell opening with a door-like structure called an operculum (snails do this).

Limpets seal themselves against the hard substrate using suction and produce a mucous layer at this interface to create a watertight seal.

Limpets seal themselves agains hard substrate in the intertidal zone

Air exposure leads to greater temperature fluctuations and extremes.

Mobile animals such as crabs avoid the largest temperature changes by shuttling between cooler and warmer environments. This technique is called behavioural thermoregulation.

For less mobile animals, thermal regulation becomes more challenging.

More sensitive animals such as sea stars/ starfish are limited to the low tide zone where they’re more frequently submerged.

Others, such as some species of intertidal mollusc, have evolved internal mechanisms such as heat shock proteins and a high freeze tolerance. These help the animals to cope with extreme temperature variations in the high tide zone.

Tidal pool at the beach. Posted by Ocean Generation.

The intertidal zone is characterised by severe changes in oxygen availability.

Particularly in overcrowded tide pools, when many animals are aggregated together during low tide, increased respiration can reduce water oxygen content to critical levels.

In response to this, some intertidal animals can switch to aerial respiration and take in oxygen from air instead of water.

For example, the high intertidal porcelain crab (Petrolisthes) has an aerial gas exchange organ on each of their walking legs for air-breathing during periods of emersion.

Porcelain crabs can take oxygen from air instead of water. Posted by Ocean Generation.

On sandy shores, some species of mudskipper will repeatedly emerge at the surface of their burrows and take in mouthfuls of air. They deposit this air into a specialised chamber within their burrows to protect themselves and their eggs against hypoxic (low oxygen) conditions.

On sandy shores, activities of some intertidal creatures can influence local oxygen availability.

Lugworms burrow deep into the sediment, feeding on organic material in the sand and creating U-shaped burrows deep below the surface. These burrows help to rework and ventilate the sand. This process is known as bioturbation, which increases localised oxygen availability.

They spend their lives filtering out organic material from the sand, pooping out wiggly mounds of undigestible sand to the surface, known as ‘casts’.

Lugworms burrow deep into the sediment in intertidal zones.

All intertidal habitats are impacted by fluctuations in salinity.

Heavy rain or river inputs can make coastal water fresher, and evaporation and droughts can cause hypersaline (saltier) conditions.

On sandy and muddy shores, intertidal worms move vertically up and down their burrows along a salinity gradient until they reach more favourable conditions.

Other animals maintain their internal osmotic (salt and water) balance in the same way that they protect themselves from water loss. Some clamping to the substrate (limpets); others closing their operculum (snails); or moving to more favourable environments (crabs).

The shallows are exposed to ultraviolet (UV) radiation from the sun.

This can cause DNA mutations and damage to molecules needed for key biological pathways.

To combat this, the aggregating anemone (Anthopleura elegantissima) contracts during peak levels of UV radiation. It attaches debris to its column for extra protection against harmful sun rays: Just like putting on a sunhat.

Other intertidal animals have even evolved ‘sunscreens’. These are absorptive, reflective, or light-scattering pigments in their skin and mucus which help to protect them from the damaging effects of sun exposure.

For example, Irish moss (Chondrus crispus) is the reddish leafy seaweed that can be found on rocky shores and tide pools across the UK and Ireland. If you look closely, you’ll see that it looks slightly iridescent in the light.

This is because the tips of the growing fronds are covered in multiple, transparent layers. When sunlight hits these layers, it’s reflected away from these delicate regions, protecting this alga from harmful UV rays.

Irish Moss reflects sunlight to protect from harmful UV rays

To avoid being swept away by wave action, intertidal animals must hold on tight.

Barnacles secrete cement, while mussels produce a sticky thread called Byssus threads to attach themselves to the rock. Once attached, these sessile animals remain in position for most of their lives.

Other intertidal creatures rely on suction. Sea stars (starfish) have rows of tube feet on their underside. Each of their feet has a sticky, suction cup at its end that help it hold on to the rocky substrate. These also come in useful to prise apart the shells of bivalves to eat.

Sea stars have rows of tube feet to stay in place

Many adaptations are shared among diverse animal groups.

This is an example of convergent evolution: when similar features independently evolve among different species under the same pressures.

Understanding the challenges overcome by animals living at the interface between land and sea may allow us to better understand our own historical transition from Ocean to land, millions of years ago.

So next time you’re at the coast, see if you can spot some of these creatures and their adaptations. (Remember, they’re under enough stress already, so be respectful and don’t touch, poke or prod at them).

Take a moment to appreciate the incredible feat of survival achieved by the Ocean creatures that not only survive but thrive in this extreme environment.

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Jemma Sargeant

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19. 06. 2024 Jemma Sargeant

The motion of the Ocean explained: Waves and tides

Motion of the Ocean explained by Ocean Generation.

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The Ocean spends its life in perpetual motion.

From the smallest ripple to the largest storm wave, energy from the Ocean is one of the most powerful forces on our planet. They have carved the shape of our coastlines over thousands of years.

Many of us observe the constant motion of waves and tides, but few of us ever stop to consider how these not-so-simple certainties actually work.

What are Ocean waves, and where do they come from?

First things first, Ocean waves are the transfer of energy across a body of water, not the movement of water itself.

Surface waves are caused by wind out at sea. As the wind blows across the Ocean, particles near the surface are disturbed. Friction and pressure generate ripples, and this wave induced pressure causes each individual water particle to push and pull on its neighbour.

The water molecules begin to move up and down in a circular orbit, creating a wave crest. This motion propagates energy through the water in the direction of the wind.

Once they have enough energy from the wind, these wave crests spread out and begin their journey across the open Ocean as “swells”. These swells can travel uninterrupted for thousands of miles, until they reach the shore and meet their dramatic end.

As the wave approaches shallower water, the circular orbits of the water molecules in the lower part of the water column are disrupted by the seafloor and get slowed down by friction.

The water molecules closer to the surface are less effected by friction, so the energy continues to move through them at its original speed.

The wave grows in height but is left unsupported as the lower part is dragged along the seafloor. Eventually, the wave finds itself with nothing underneath it, and collapses in a dramatic fashion, known as the wave “break”.

A wave break is when a wave collapses. Posted by Ocean Generation, leaders in Ocean education.

Another form of Ocean waves that move across our planet are tides.

The predictable rise and fall of the Ocean along our shores is as certain as the sun rising in the East and the stars coming out at night.

For centuries, humans have learned to predict the tides for navigation, fishing and other recreational activities.

But to fully understand how tides work, we must look up to space.

The moon and Earth both exert a gravitational force and are constantly accelerating towards each other in orbit.

As our planet accelerates towards the moon, the water on the side closest to the moon accelerates faster than the solid rock in the middle and accumulates to form a slight bulge.

This is known as tidal bulge.

As the Earth rotates, this watery swell stays in the same position relative to the moon. The land rotates into this bulge at high tide, and out of it at low tide.

So, when we stand on the beach and watch the tide going out, what we’re actually observing is the Earth rotating away from the Ocean.

Ocean waves and tides have been shaping the universe. Posted by Ocean Generation.

But wait a second, why are there two high tides per day?

This is where things get a bit more complicated. Put your scientist hats on, and imagine the following:

While the water on the near side bulges towards the moon, the water on the far side bulges away from the moon.

Remember that the moon and Earth are constantly accelerating towards each other in orbit.

A centrifugal force (a force which acts on an object that’s rotating) acts as a result of this spinning.

On Earth, this centrifugal force is strongest at locations facing away from the moon, causing the water to bulge away from the moon at the far side.

Earth therefore rotates into two tidal swells each lunar day of 24 hours 50 mins.

What is a lunar day?

A lunar day is the time it takes for a specific point on Earth to rotate from an exact point under the moon to return to the same point under the moon.

This explains why there are two high and two low tides per day, and each high tide occurs 12 hours and 25 minutes apart.

To understand how Ocean tides work we have to look up to space.

The sun also has a gravitational tidal force on our Ocean: It’s called a solar tide.

However, it’s much smaller since the sun is much further away.

When the sun and the moon are aligned, their lunar and solar forces combine to create a larger tide, known as spring tide.

In contrast, when the sun and moon are at a right angle, their opposing tidal forces partially cancel each other out, creating a smaller tide. This is known as neap tide.

Back on Earth, the shape of the coastline can have a dramatic influence on tidal magnitude.

For example, the highest tides in the world can be found in the Bay of Fundy, Nova Scotia, Canada. The size, depth and unique funnel-shape of this coastline causes a natural oscillation (a back-and-forth movement in regular rhythm) of the water in near-perfect sync with the tide, which has an amplification effect.

So next time you’re taking a stroll along the coast and listening to waves crashing against the shore, take a moment to consider the forces in play to make it all possible.

Waves and tides are all part of the continuous movement of energy that has formed and shaped our universe since the beginning of time.

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Jemma Sargeant

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3. 05. 2024 Olivia Jones

Are hydrothermal vents the origin of life on Earth?

Hydrothermal vents explained by Ocean generation.

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Thousands of metres down in the Galápagos Rift valley, a deep-sea camera is towed along the seafloor, capturing our first glimpse of an extraordinary and alien world.

Towering chimneys pumping out plumes of black smoke cover the seabed; these are hydrothermal vents.

Despite low oxygen levels, high toxicity and fluid temperatures of up to 350°C, hydrothermal vents host a remarkably diverse array of Ocean life.

These Ocean creatures are specially adapted to these extreme conditions: Giant tubeworms, beds of mussels and clams, fluffy crabs, pink vent fish and more.

The discovery of hydrothermal vents in 1976/ 1977 prompted a new branch of deep-sea biology. Since then more and more species have been discovered.

Hydrothermal vents may hold the secret to the origin of life on Earth. — *Image credit: Meteored*

Where are hydrothermal vents found?

Hydrothermal vents were one of the first environments to have existed on Earth and have been bubbling away for over 4 billion years.

Hydrothermal vents can form anywhere a heat source meets a fluid system. They often occur on the seafloor at tectonic plate boundaries. The hot, upwelling magma heats up seawater which is ejected as mineral-rich plumes.

They are mostly found in the abyssal zone of the Ocean (3,000 – 6,000m). While the majority (65%) of the hydrothermal vents are located close to the tectonic plate boundaries, they are also common (12%) along chains of underwater volcanoes, called volcanic arcs.

In 2000, a new type of vent was discovered, located several kilometres from a divergent plate boundary (tectonic plates that are moving apart) called Lost City vents. They resemble the spires of an underwater metropolis like Atlantis.

Hydrothermal vents are found at tectonic plate boundaries. Posted by Ocean Generation. — *Image credit: Pearson Education*

Take a look at some of the weird and wonderful Ocean life found in the deep-sea:

**Annelid tubeworms (Riftia pachyptila)**

Also called ‘giant tubeworms’, these are extremophiles, meaning they’re able to live in extreme environments, and can reach over 1.8 metres (six feet) tall.

They have a unique body plan with no mouth or anus and their lifestyle is unique, too as they rely entirely on symbiotic bacteria as a food source.

**The Yeti Crab (Kiwa hirsuta)**

This new family of crab was discovered in 2005 and has claws covered in dense setae (stiff bristles). They get almost all their food from the chemoautotrophic bacteria (bacteria that can turn inorganic chemicals into energy) that live in these bristly structures.

These furry crabs have been seen to wave their claws to help provide a flow of oxygen and minerals to their symbiotic bacteria.

**Pompeii worm (Alvinella pompejana)**

Named after the explosive eruption of Mount Vesuvius in Pompeii, the Pompeii worm is the most heat tolerant animal we know of. They can survive temperatures at high as 80°C. One physiological adaptation Pompeii worms have evolved to survive these extreme temperatures are heat shock proteins. These’re specific proteins which provide cells with thermal stability.

Some Ocean creatures specifically adapted to these conditions. — *Image credit: 1. Yeti crab: MBARI 2. Tubeworms: Britannica, 3. Pompei worm: Wikipedia*

So how are these marine animals living in such extreme conditions?

Photosynthesis often gets all the credit for providing the energy that flows through food webs by converting light energy into food.

However, there is another lesser-known reaction. Chemosynthesis does the same thing but draws from chemical energy instead. This reaction is what supports the diverse communities we see at hydrothermal vents.

Could hydrothermal vents have sparked the origin of life on Earth?

Chemosynthetic bacteria found in these communities use the toxic hydrogen sulphide released by hydrothermal vents to convert carbon dioxide into organic carbon molecules.

These form the building blocks to all life on Earth.

It’s this nifty reaction that’s enabled deep-sea organisms to adapt and survive at hydrothermal vents.

Animals living here have formed symbiotic relationships with these bacteria which can be incorporated into tissues (endosymbiosis) or on the animal surfaces (ectosymbiosis).

These chemosynthetic bacteria provide energy from the environment for their host. This can be so efficient that some creatures (such as the annelid tubeworm) don’t need to feed at all.

The discovery of these self-sufficient ecosystems cast new light on the origins of life on Earth. It was here that the unique conditions were suitable for a spontaneous metabolism (the spontaneous formation of molecules that are essential for all life) to occur.

This discovery gave rise to the question: Does the Ocean hold secret to the origin of life on Earth?

Theories on the origin of life range from lighting speeding up reactions to comets delivering organic molecules from outer space.

The ancient process of chemosynthesis precedes photosynthesis, and likely sustained the earliest life on Earth.

Bacteria were some of the first life forms to emerge. The most striking piece of evidence are the parallels between the chemistry spontaneously occurring at these vents and the core metabolic reactions found in these single-celled organisms.

Thesel vents may hold the secret to the origin of life on Earth. — *Image credit: Meteored*

Cyanobacteria are an ancient group of photosynthetic microbes which represent one of the earliest forms of life on Earth. With fossils dating back to 2000 – 3500 million years ago, these single-celled organisms evolved photosynthesis, allowing life to rise up from the darkness below.

The rest is history.

Since their discovery, hydrothermal vents have become the most popular theory among scientists for explaining the origins of life on Earth. Yet much remains to be discovered. Secrets still held within these mysterious ecosystems have the potential to revise our life-on-Earth theories once again.

Cover image via Research Feature.

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Olivia Jones

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