Everything You Need To Know About The Environmental Impact Of Overfishing

Overfishing is not something that we think about often but for anyone who has made the change or is considering the impact of their food choices on the planet; the fishing industry is a point of concern.

This is because we have more access to information regarding climate change and we are learning of the harsh realities of certain industries and companies that work to exploit the earth and our future. With Netflix releasing a range of documentaries with a focus on the state of our oceans like Seaspriacy, A Plastic Ocean and Chasing Coral, we know the important role we play in conservation and protection.

When it comes to the fishing industry, sadly, the direction it is going in is nothing but environmentally destructive. Our demand for seafood and certain fish species has led to what is now referred to as 'Overfishing' and the increase in growth for this sector is not slowing down.

Environmental impacts of Overfishing

Overfishing is defined as the practice of taking fish from the sea at rates too high for species to replace themselves. Practices of overfishing could lead to species extinction and, therefore, a complete alteration of their habitats.

The leading cause of overfishing are the techniques used in the fishing industry, such as bottom trawling and drift net fisheries. These techniques usually capture not only the target species but also many other sea animals. These non-target animals caught alongside the fish are known as bycatch.

Overfishing is the primary threat to the ocean’s biodiversity!

“A third of commercial fish stocks are being harvested at biologically unsustainable levels and 90 percent are fully exploited, according to the UN Food and Agriculture Organization.
The population of Pacific bluefin tuna, for instance, has plunged 97 percent from historic levels due to rampant overfishing of one of the ocean’s most ecologically and economically valuable top predators”.

The National Geographic 2019

The Fishing Industry

Perhaps not everybody knows, but the ocean covers 71% of the earth's surface. Fish are consumed in every region of the world.

The fishing industry has expanded enormously in the last century, and illegal fishing practices are not the exception. In many cases, consumers can’t know whether the fish they buy comes from legal or illegal practices.

Furthermore, commercial fleets are going far deeper down the food chain for viable catches due to a decrease in certain species. This is known by the term fishing down the food web and it is causing a chain reaction that is leading to further distress of the oceans biologic systems.

Overfishing leads to species extinction. Those that cannot reproduce due to the high fishing rates of this industry eventually disappear or become severely threatened. In addition to this, 40% of the animals that are caught from the ocean are non-target species. This means that they end up back in the sea dead or injured and left to die.

"The number of overfished stocks globally has tripled in half a century and today fully one-third of the world's assessed fisheries are currently pushed beyond their biological limits"

Food and Agriculture Organization of the United Nations.

Overfishing is a contributor to climate change

The ocean is the main carbon sink in the world.

Fish play a leading role in this capture since their vertical movement causes surface carbon to go to the ocean’s bottom and stay there stored. When we threaten these ecosystems, most of the animals and plants responsible for the carbon capture are affected.

Fisheries have depleted most of the fish stocks in oceans accountable for this phenomenon, affecting the carbon sequestration process.

Also, bottom trawling practices cause significant damage to deep marine sediments, and they are responsible for releasing vast amounts of CO2 from ocean soils. In 2019, the release of CO2 into the atmosphere caused by bottom trawling was more than the entire CO2 released by global flight traffic.

Overfishing represents a threat to ocean ecosystems

Every animal has a function in the ecosystem.

This means that if only one species gets extinguished, then the whole system suffers an alteration.

Here are some examples:

· Sharks

These predators play a central role in the ecosystems. They keep the balance and health of oceans by eating species that are sick and weak. They regulate species abundance and diversity.

· Turtles

They provide the ocean and coasts with nutrients that are key for these environments. Also, soil grassing is essential for seagrass health and, therefore, to keep carbon stored in oceans.

· Seabirds

These animals are responsible for transporting nutrients from oceans to islands, thus contributing to a healthy habitat for both environments.

Fishing techniques

Bottom Trawling

Towing a trawl (fishing net) over a large section at the bottom of the ocean to catch massive amounts of fish - and sadly bycatch - at one time. This is an incredibly harmful practice and one of the most destructive methods that companies use to catch fish.

Blast Fishing

Bombs of dynamite are dropped into the water to kill the fish and then they are skimmed from the surface of the water - it also damages the coral reefs and surrounding ecosystems.


A method used across regions of Southeast Asia where heavy blocks are suspended by crane and dropped repeatedly down on the reefs to break them and scare out the fish which are then caught in a net - this has done irreversible damage to many of the reefs.

So what are the solutions to overfishing?

The best solutions to overfishing are to reduce our fish and seafood consumption, or at best, stop eating fish and embrace plant-based food sources. Please reconsider your need to consume seafood and threatened species of fish.

Think about it? How can we say we care about the ocean through advocacy of sustainable practices like going zero-waste, demanding plastic-free options, saying no to straws and plastic bags; whilst continuing to eat seafood?

Bycatch is where millions of sea animals, including endangered and vulnerable species, getting trapped and killed by nets, lines, traps and more. This is not only an ethical problem but an ecological one.

Million Dollar Vegan

No matter the technique used, fish are being taken from the ocean at a rapid rate; thus, their habitat is altered.

Today, the situation is critical. So any fishing practice, as sustainable as it may be, will contribute to the problem of overfishing.

If you are still eating fish and seafood - support local fishing businesses that avoid practices (like bottom trawling) that are harmful to the ocean and coral reefs and look for sustainable or wild-caught fish. According to the Marine Conservations Society, you will definitely want to avoid bluefin tuna, swordfish, skate and eel as the stocks of these are all too vulnerable.

What about farmed fish?

This form of fish and marine life production is an expanding market especially in destinations such as China, India, Indonesia, Vietnam, Bangladesh, Egypt, Norway and Chile. Just because farmed fishing is done within a controlled environment does not mean the process is sustainable.

Fish farming is where fish and other kinds of seafood are purposely raised in enclosures for the sole purpose of food production. The fish are kept in unnatural surroundings with limited space to freely move.

Since the animals are retained in small spaces, aquaculture practices are very vulnerable to be affected by infectious diseases with high mortality rates. On the other hand, vast amounts of waste are generated during farming and food production for these species.

Research shows us that in 2018 inland aquaculture (rivers, lakes, and fish farms) produced a staggering 51.3 million tonnes of aquatic marine life that accounted for over 60% of the global farmed fish production.

Fish farming is not a solution but a bigger problem.

Final Thoughts