The impact of overfishing and what you can do about it

The impact of overfishing and what you can do about it: Explained by Ocean Generation.

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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Why do marine animals migrate: Everything you need to know  

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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Re-thinking the shark stereotype

Rethinking the shark stereotype. Posted by Ocean Generation

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).  

Sharks are one of the most diverse groups of predators

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.

Sharks come in many shapes and forms

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. 

The population of sharks has plummeted

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.  

We need to protect sharks

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