Environmental Impact of Fishing

Fish is a popular protein for many people, especially health-conscious consumers. According to the Food and Agriculture Organization, fish makes up about 17 percent of the world's protein intake. In islands and coastal communities, it goes as high as 70 percent.

As more people consume fish, there are concerns about the environmental impact of fishing on our oceans and water bodies. 

While many are familiar with the impact of meat and dairy products on the environment, many may not know that unsustainable and unscrupulous fishing also significantly contributes to the pollution and damage of our marine environments. 

Read on as we explore the environmental impacts of fishing and find ways to minimize them. 

The fishing industry 

The fishing industry involves catching, processing, and selling fish for commercial or recreational purposes. 

Fish plays a critical role in our nutrition and food security. Billions of people worldwide rely on food from the ocean as a significant part of their protein. Furthermore, fishing is also a source of income for many people worldwide. Commercial fishing and Aquaculture are two primary fishing methods for catching the fish we consume. 

Commercial fishing industry 

This involves taking fish, marine species, and other resources from the oceans, lakes, and water bodies to market them. People can undertake this type of fishing on a small scale with small fishing vessels and little mechanization or on a large scale with deep sea fishing vessels and sophisticated mechanization. 

The types of fish caught for commercial fishing fall into two categories: demersal (fish living at the bottom of the water or sometimes mid-level) and pelagic (fish living in the open sea close to the surface). You can sometimes find both categories of fish in coastal regions. 

People employ various practices for commercial fishing. These practices include bottom trawling, longline fishing, and so on. Sadly, some of these fishing methods significantly threaten the environment. 

Aquaculture fishing industry 

Over the years, Aquaculture, also known as Aquafarming, has increased in popularity to yield more fish and meet the growing demand for seafood.

The World Resources Institute (WRI) predicts that farmed fish and shellfish production will increase by 133% by 2050 to meet the growing demand⁷.

Aquaculture involves the cultivation of freshwater or marine organisms, especially shellfish or food fish, under controlled conditions.

There are two main types of aquaculture: marine aquaculture and freshwater aquaculture. Marine fish farming is typically done in tanks on land or net pens in water. Freshwater farming takes place in ponds or manmade systems. 

Aquaculture is considered sustainable but can also risk destroying ecosystems and natural habitats. Nutrient build-up from farming fish is one issue that affects the environment. These nutrients (dead fish, feces, and rotten food) accumulate as waste, causing oxygen depletion. The added use of pesticides and antibiotics also further damages the marine environment. 

Read more: Is fish farming sustainable?

Environmental impacts of the fishing industry

While the fishing industry contributes to providing fish for commercial purposes and a source of income for individuals, it has also affected marine conservation, including fish populations, habitat degradation, and water pollution, amongst other issues.

Research reveals that if the fishing industry continues on this path, wild-caught seafood will not exist by 2048⁸ (although this claim has been disputed by many, the decline isn't).

In this section, we will look at the negative environmental impact of the fishing industry. 

Destruction of habitats 

Some industrial fishing practices can lead to aquatic habitat destruction.

Bottom trawling is a popular fishing technique that involves pulling fishing nets across the ocean floor to catch fish at the bottom of the sea. This fishing technique destroys coral reefs, sponges, and oysters that comprise the marine habitat. Ultimately, this practice is harmful to wild fish populations. 

Research reveals that bottom trawling takes out around 5% to 25% of an area’s seabed life with just one run².

In addition, many pollutants that have settled into the sediment get reintroduced into the food chain. 

The United Nations estimates that bottom trawling accounts for 95% of ocean damage. The United Nations General Assembly also recommends temporarily banning the practice of bottom trawling on high seas.

Blast fishing and cyanide fishing can harm surrounding natural environments and are illegal in many areas. While blast fishing involves using explosives, cyanide fishing involves using cyanide to catch fish. These techniques may be lucrative for fishermen but destructive to coral reefs and marine life. With marine habitats destroyed, the fish stocks of many target species may begin to decline. 

Ghost fishing 

Ghost fishing is one occurrence that can be a threat to marine life. Ghost fishing occurs when trawler nets or fishing gear gets discarded at sea but drifts to capture wild fish. This fishing gear can capture many animals, including wild fish and birds that swoop into the water to find prey.  

According to a case study, lost fishing gear could become a ghost pot attracting sea turtles. Sadly, these sea turtles can get into the pot but would find it difficult to get out. In Georgia, a single ghost pot contained 130 dead sea turtles⁶.

Overfishing 

Another major impact of fishing industries is overfishing. This refers to removing target fish species at a higher rate than the fish stocks replenish themselves. Overfishing can occur in various water bodies, including lakes, ponds, oceans, and high seas.

Ultimately, this puts heavy fishing pressure on wild fish populations. In addition, sustained overfishing can distort marine ecosystems. 

According to FAO reports in 2020, in 2017, 34% of the world's fish stocks were overfished.

Overfishing has also led to the threat of many species. Some of these species are on the “IUCN Red List” and face the risk of extinction. These fish include Atlantic cod, Atlantic Salmon, Bluefin tuna, Red snapper, etc. 

Bycatch 

Bycatch refers to fish or other marine animals caught unintentionally while harvesting particular fish species. Fishing practices like longline fishing are a major culprit of bycatch. As lines are employed in the open ocean, sea turtles and other aquatic animals are prone to capture. 

These sea turtles go for the bait on the lines, and the hooks get lodged in their mouths, preventing them from reaching the sea surface. 

Marine mammals like birds flying over the open seas get attracted to the bait and ensnared in the fishing gear, causing them to drown. Other fishing practices like bottom trawling can also lead to increased bycatch. The number of animals killed unintentionally can ultimately impact the marine food web. 

Over-exploitation of marine ecosystem 

Overfishing and other unsustainable practices can lead to over-exploitation of the marine ecosystem. These fishing operations and practices' adverse physiological and psychological effects can affect fish populations and increase bodily injuries and stress levels. 

Fishing in-demand species can disrupt the food web. Prey species like sardines may become scarce, reducing the food supply for predators. On the other hand, prey species may be on the rise while predator species like salmon and tuna are targeted.

Pollution, overfishing, and bottom trawling of the ocean floor can affect the carbon stored in the ocean, contributing to the climate crisis. 

Marine debris 

Another environmental impact of the fishing industry is mass marine debris. Marine debris typically consists of lines, buoys, and nets. 

Studies reveal that only fishing nets comprise 46% of plastic debris in the Great Pacific Garbage Patch⁴. Another study shows that nets, buoys, and lines comprise two-thirds of ocean plastic debris¹.

With marine debris floating in water bodies, marine animals can either get entangled in debris or ingest them. Both of which are harmful to them. This debris can also lead to ghost fishing, where ghost pots or nets capture unintended fish species. 

Recreational fishing impacts 

Catching fish for sport or leisure is what we call recreational fishing. Angling, one of the most common forms of recreational fishing, involves using rods, lines, hooks, reels, and a wide range of baits. 

A study reveals that recreational fishing accounts for almost a quarter of the fish caught in the United States⁵. While many consider commercial fishing to have one of the greatest environmental impacts, recreational fishing can also significantly impact the environment.

Recreational fisheries typically target bigger fish, meaning they take the most healthy and fit fish out of the population. Through harvesting, recreational fishing can contribute to fishery decline as well as disruptions in the ecosystem. 

Recreational fishing boats can also cause traffic, which comes with erosion, waves, noise pollution, and environmental degradation. A study suggests that improving recreational fisheries management on a global level can increase social benefits on the same scale as improving commercial fisheries³.

Minimizing the negative environmental impacts of fishing

Poor fisheries management and illegal, unreported, and unregulated (IUU) fishing negatively impact the environment and reduce the potential of fish to provide food and jobs.

In this section, we will look at several ways to minimize the environmental impact of fishing. 

Improved fisheries management 

It is arguable among the fisheries science community whether traditional fisheries techniques like the harvest quota work to restore fish populations. However, fisheries mismanagement is a major cause of the decline of fish populations.

Using effective modern fishery management systems and sustainable practices is essential to reduce the environmental effects of fishing. 

According to National Geographic,

“Sustainable fishing guarantees there will be ocean and freshwater wildlife populations for the future”

To prevent the destruction of habitats, something as minor as changing fishing gears can make all the difference. Going for a different hook or bait design can lead to less dangerous fishing practices and bycatch. 

Government bodies and international organizations have also designed policies to help reduce the impact of fishing on the environment. These laws and policies could include limits on fishing vessels allowed to be used in certain areas, quotas on the number of catches for some species, prohibition of spears and baits, etc. 

Marine reserves 

Marine reserves typically work to ensure marine wildlife's safety and the environment's protection. These reserves designate marine protected areas and mitigate the negative impacts of fishing within that environment. 

Marine reserves are designed to create and enhance biodiversity within an area. For example, coral reefs involve the application of these marine reserves to establish marine protected areas. Several marine reserve initiatives have been established in countries like the Caribbean, the Philippines, and the United States. 

Aquaculture/fish farming 

Another way to minimize the environmental effects of wild-caught fishing is to switch to more sustainable fishing techniques. One of these practices is aquaculture or fish farming. 

Aquaculture is considered a more sustainable fishing technique than traditionally catching wild fish.

Typically, fish farms on the coastal waters involve pens and cages attached to the sediments at the bottom. With many wild fish depleted, supplying farmed fish consisting of the commonly consumed species is a great way to supply large quantities of fish for human consumption. 

However, as we looked at earlier, Aquaculture has flaws. Fortunately, there are various ways to ensure fish farming is sustainable. Here are a few tips to make fish farms more sustainable: 

Choose a good farm

For organic fish farming, choosing the farm itself is as important as choosing your farmed fish species. Avoid environmentally sensitive areas like swamps and coral reefs when choosing fish farms. Establishing a fish farm in sensitive areas can lead to biodiversity loss, disrupting the entire ecosystem. 

We have two major types of fish farms - the extensive and intensive fish farming system, with different types of farms in both systems. Examples of fish farms include ponds, cages, tanks, bio-floc fish farming, etc. 

Select the right fish species.

After choosing a fish farm, another crucial thing to decide is the type of fish species you want on your fish farm. Choose species that keep the ecosystem healthy to grow a sustainable fish farm. 

Invasive non-native species, plants, and animals that do not grow naturally in a location can spread quickly, displacing native species and even completely eradicating their natural habitat.

Native species, on the other hand, have natural traits that best suit the local ecosystem. These native species are also in high demand within the locality, allowing farmers to profit.

Related read: Types of Fish & Fish Species. Most sustainable fish.

Manage fish feeding 

Fish feed contributes a large amount of waste to the environment. Fishes may ignore the fish feed, which sinks to the water's bottom. As this accumulates, it reduces the quality of the water, decreasing further yield. You want to invest in high-quality fish feed designed for your fish species to improve the health of your fish and farm. 

Many fish farmers try to overfeed their stock to increase growth. However, this eventually leads to waste, polluting the water and increasing mortality risk. 

Reduce the use of veterinary drugs and chemicals 

Farmers use veterinary drugs to keep fish healthy and chemicals to prepare the water and remove predators.

These chemicals and drugs can seep into the natural environment. Since the chemicals were designed to kill pests like snails, they can do the same in the surrounding environment. 

Invest in the proper farming knowledge to avoid this and go for natural alternatives. Also, if you're treating a sick fish, you want to do this in a separate environment to prevent chemicals from entering the surrounding environment. 

Final thoughts on the environmental impacts of fishing 

While fish is a high source of protein and a means of livelihood for many people worldwide, it also comes at a high environmental cost. Unsustainable fishing practices can reduce fish populations and disrupt the entire ecosystem. To minimize the negative impacts of the fishing industry and preserve fish stock, more sustainable practices need to be introduced.