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The Devastating Effects Of Overfishing

by Liam Williams
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During a time where our collective lifestyle choices make such an impact on our planet and its environment, it’s important not to take advantage of the fact that we’re one of the most intelligent primates that ever roamed the earth. The amount of meat and fish we eat in the developed world is one of the primary factors causing this dramatic shift in our environment and ecosystem, even though there are over a billion malnourished people who don’t have the same privilege and access we do in the western world. All life started in the oceans of the world. Even today the marine ecosystem is arguably the most important on earth. After all, nothing can live without water. Even still overfishing is prevalent in almost every major coast of the world.

Two trawlers pulling a large net. One of the most destructive overfishing methods

The effect of all these things has already started. A huge issue is that people don’t see the urgency of stopping these detrimental habits because they’re not directly affected by it yet. This is totally ignorant. Cities around the world are already beginning to see water levels rapidly rising which can be dangerous for residential areas, as well as for farmland. This article will be about how overfishing affects all of us, why government and huge companies refuse to heed the warning of educated officials and the planet itself, and some solutions to this now dire situation. 

What is Overfishing?

Overfishing is the practice of depleting the stock of fish a body of water faster than they can repopulate. By now we all know what overfishing looks like, normally involving a large 40-50 ton fishing vessel with big nets that can hold of thousands of fish. Fish obviously isn’t the only thing catch with their huge 12-meter trawl nets, turtles, sharks, dolphins, and many other marine species that can get caught and lifted onto the trawler. While many are thrown back it becomes more than threatening an entire species of fish when you hear the facts of how shark fins are harvested. It becomes animal cruelty. 

Thousands of fish caught in a trawl net as a result of overfishing

Shark Fishing

Shark fins are harvested off sharks that have been accidentally caught in a trawl net. While the shark is live the fin is cut clean off it, then the rest of the live shark is discarded. Fins are one of the most important components of a sharks anatomy, without it, it cant turn or keep themselves up in the water so it sinks to the ocean floor, and dies, often of starvation. Sharks have been around longer than almost any current species on earth. They’re not just being threatened through unmanaged shark fishing, but also through the destruction of their own environment. Overfishing can and has happed to an extent that entire reefs have been cleared out of most fish, leaving behind a barren sea bed made from dead coral and bottom feeders. 

Amputated shark fins and parts as a result of overfishing

Who is Responsible for overfishing?

The short answer is: in a sense, everyone is, with some exceptions. Primarily though the blame rests on the shoulders of the of these massive corporate giants who finance the fishing boats and give the word for how much of every fish is required to meet that month’s quota. While the debate that they’re feeding the earth is partly valid it shouldn’t be at the expense of the oceans, and species that have been around for far longer than we have. The oceans are close to reaching their breaking points and around a billion people around the world are still malnourished. So it obviously can’t be the answer. Because it’s not sustainable. 

Fishing boat in the atlantic

The general population holds some of the blame because of a national addiction to convenience. All across developed countries around the world. One-stop-shop supermarkets that make our shopping cheaper and more convenient. We don’t have to look at the conditions that beef or chicken was raised in, or how ethically that nicely filleted and packaged fish was caught. They make it easy that way on purpose. 

Another group responsible for destructive practices are the people who rely solely on the fish to survive. Underdeveloped fishing villages and towns are catching fewer and fewer fish every year. Fish they use to feed their village. Because fish stocks have been deleted they often have no choice but to resort to these measures. 

Destructive Fishing Methods

Some fishing practices are less harmful than others. Never the less there are some that easily cause permanent and irreversible damage to marine life and their habitat. While some, thankfully even most of these practices are illegal, reinforcement of these laws is weak at best.

Blast fishing 

Blast fishing. A devastating method of destructive overfishing

Blast fishing is a popular method across east Africa and Asia. It involves detonating a homemade explosive (often made from an ammonium nitrate and kerosene mixture) underwater. The underwater shockwave produced by the bomb stuns the fish and ruptures their swim bladder, causing them to float to the top for easy collection. It’s an incredibly ineffective and inefficient method of fishing. For every ten fish killed in the blast, only two floats to the top for collection, the rest sink to the ocean floor. Coral reefs are also heavily affected by blast fishing. The blast destroys the coral’s calcium carbonate skeletons. Sufficient blast fishing can leave fields of coral rubble on the ocean floor, without a proper functioning ecosystem. 

Dead fish floating on the surface of the water as a result of overfishing

Most countries exercise anti-blast fishing laws, although enforcing them is a different story altogether. In places like Tanzania where blast fishing is prominent, have taken a joint approach between authorities and civilian committees. They help provide information as well as identify perpetrators and the associations that employ this method of fishing. 


Trawling is a method of fishing that involves one or two boats, called trawlers, pulling one huge trawl net through ocean waters. Trawlers vary in size anywhere from 30 horsepower to 10,000 horsepower that work either alone or together (known as pair trawling) to collect tonnes of fish every day. Trawling is one of the most effective methods of catching massive amounts of fish, perhaps too effective. More than just target fish are caught in huge trawl nets while their ecosystem gets turned upside down as it drags across the ocean floor.

Large industrial fishing boat used for overfishing

Pieces of nets are often left in the ocean after being damage. They don’t biodegrade and more often than not, and the animal gets snagged in a piece, often killing it. Bottom trawling stirs up sediment and caused large scale destruction on the seabed.

A dead ocean seabed

Bottom vs Midwater Trawling

Trawling can be divided into two categories depending on which collum of the ocean is being fished. Midwater trawling, also known as pelagic trawling, catches pelagic fish such as mackerel, tuna, shark, and herring. Bottom trawling targets bottom-feeding, semi-pelagic fish like halibut, flounder, cod, and brill. The nets and gear used to catch and reel these fish vary greatly. From mesh size, chaffing gear, hydraulic machinery, and more. 

Cyanide Fishing

Cyanide fishing involves spraying a habitat of fish with sodium cyanide, which stuns them. It was originally used for the collection of aquarium fish because it often doesn’t kill the fish. Not long after though, it started being used as methods for food fishing. As well as making the ocean flood poisonous to other marine life, the sodium cyanide bleaches the corals, turning them into dead, white, empty structures. Cyanide fishing is thought to have originated in the Philippines in the 1950s, although because of its lack of publication and official approval its origins are unclear. 

Cyanide fishing, a harmful method of overfishing

Fishermen dive down to the ocean floor, often without or with dangerous breathing aids, and spray the cyanide between individual layers of coral reefs. The fish are then collected and bagged for aquariums, or sold to the fish markets. There is a 75% mortality rate after 48 hours for the marine creature left after the fishing stops. These reefs can take decades to recover, and sometimes, don’t recover at all.

A dead coral reef

More than two-thirds of the fish caught this way die on transport to their destination due to stress. Even if they don’t die they’re bound to have a shorter lifespan than other fish caught ethically. Fish caught through cyanide fishing often sell cheaper or not at all to aquariums and pet shops due to their tendency to die. Extremely low wages with no alternate source of income force fishermen to take these alternate routes that risk their health and freedom.

The Effects of Overfishing

The effects and consequences of overfishing have already started to show on coasts across the world. The most overfished sea in the world is the Mediterranian. Over 60% of its fish stock is now confirmed as ‘overfished’ and is at risk of being depleted. 

Imbalance of the ecosystem

The animal kingdom is a complex system where one heavily affected part, can cause a ripple effect, rendering entire habitats uninhabitable. When you overfish a certain species of fish, their prey thrives and overpopulates. At the top of the oceanic food chain is the shark, a heavily overfished marine animal. When the shark population is affected it affects the entire ecosystem. If you catch most of the sharks in a particular stretch of ocean. Without the sharks, the tuna thrive and overpopulate which causes them to eat all the mackerel and other prey fish. This chain effect happens all the way down to algae that grow on the surface of the water. Miles and miles of algae topped water doesn’t allow sunlight to the bottom, making it incredibly hard for the ecosystem to jumpstart itself. 

A balanced ecosystem

Dead reefs

Dead coral reefs are not just a result of overfishing, but also of climate change. Over half of the great barrier reef is dead, endangering thousands of species on fish, crustation, and other marine species. Coral reefs provide everything to marine life from food, to shelter, to protection. Not only to the fish though. Coral reefs act as a buffer for large waves and storms in the sea so that the land part we live on isn’t as heavily affected. They buffer shorelines from waves, storms, and floods, helping to prevent loss of life, property damage, and erosion. 

Dead reef as a result of destructive overfishing

Threat to Indigenous food systems 

Fish makes up 20% of the world’s protein consumption. Many countries, particularly third world countries heavily rely on fish as their main source of nutrition. Overfishing greatly jeopardizes that.

Fishing village in south america

Unintended catches

Around 40% of the fish caught in the world are unintentional catches. They’re mostly thrown back or kept and sold either way. The fishing industry is huge. It’s estimated that the number of fish caught annually, be it for food or whatever else, is in the trillions (individual fish). Some of these unintended catches include dolphins, turtles, stingrays, and even sea birds. 

Large variation of fish caught in one net. One of the worst effects of overfishing

Severe Money Loss

Because the world’s supply of fish is decreasing at such a dramatic rate the fishing industry is losing billions every year due to new laws, regulations, or restrictions that dictate how much fish they can catch and which places are off-limits. 

the fishing Industry in decline

The solution to Overfishing

There are a few ways you can help like eating what’s in season, buying from ethically sourced fishmongers, and buying locally. The government has implemented solutions and are constantly putting new ones into place. Most common include farming, fishing quotas, bag limits, licensing, closed seasons, size limits, and the creation of marine reserves and other marine protected areas. 

Fishing Quotas or catch shares is a fishery management system that allocates a secure privilege to harvest a specific area or percentage of a fishery’s total catch to individuals, communities, or associations. Basically, it sets a species-specific total allowable catch, typically by weight and for a given time period.

Bag Limits are laws imposed on hunters and fishermen that limits the number of a certain animal they can kill and harvest. 

Licensing of ships and fishermen shows they’re qualified to fish safely and identifies them as official fish boats.

Closed seasons forbid the fishing of a particular fish while it’s in its mating season. Cod is in season from October to February, halibut from mid-march to mid-November, and tilapia is best around fall.

Size limits are to prevent the catching of bigger fish. Smaller fish typically tend to produce other smaller fish. So fishing all the large fish would dramatically decrease the average size of that species over time. 

Marine reserves and other marine protected areas come in all shapes and sizes and serve many functions. Because fishing is either heavily regulated or banned altogether in these areas, it gives the ecosystem time to build itself up. 

Fish farming or pisciculture involves raising fish in commercially built tanks that hold up to thousands of gallons of water. While farming doesn’t always reduce pressure on carnivorous fish like salmon, it can be done in an eco-friendly way.


The oceans are the origins of life and they make a huge impact all around the world. Marine life fertilizes the ocean that hosts millions of different animals and their subspecies. Overfishing will have a huge impact on all of us too, as industries weaken and famines begin. The ocean would no longer be able to perform most of its simple tasks, and as a result, we’d likely face a global catastrophe.

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