Commercial Fishing: What You Need to Know

The global commercial fishing industry is valued at $150 billion per year. Here's why it's wrecking the planet.

commercial fishing

Explainer Food Food Systems

The amount of seafood consumed across the globe has almost doubled in the past half a century. These days, most fish are farmed. In fact, fish farm production surpassed wild fish catch in 2013. Yet capture operations are still responsible for more than 93 million metric tons of fish each year — most caught by commercial fishing operations.

Commercial fishing is a $150 billion global industry — and just 2 percent of the fleet captures over 50 percent of the catch. Most of the wild fish catch comes from industrial fishing operations whose practices are depleting wild fish populations across marine ecosystems.

What Is Commercial Fishing?

Commercial fishing aims to profit from catching and selling fish. It is different from subsistence fishing, which is usually done to provide the fisher and their family with food. Commercial fishing includes fish farming — raising fish in a controlled environment for profit. These large-scale, profit-driven fishing operations kill trillions of fish every year and ignore the sentience of fishes and their ability to feel pain. 

What Does Commercial Mean in the Fishing Industry?

Any activity that labels itself as “commercial” focuses on earning money. Most commercial fishing is concentrated in the hands of companies based in a few wealthy nations, working in international waters that do not fall under any country’s particular jurisdiction. 

History of Commercial Fishing

The earliest fishing activities were subsistence-based. Eating fish may not have been very common thanks to inefficient fishing gear, and fish would have been consumed with other products of hunting and gathering, though shellfish were more easily gathered by hand. 

When fish could be preserved, catching larger amounts and trading them became possible, and lucrative. The incentives were in place to improve fishing techniques. By the 17th century, European fleets started killing whales in large numbers in the Pacific and Atlantic oceans for their oil, meat and whalebone. Sailing vessels in the Atlantic began to catch and sell cod in considerable numbers to European and African regions. The 19th century was a turning point for the commercial fishing industry, with the arrival of mechanization and engines. Now sailors could hugely increase their catch for greater profits. 

After World War II, traditional nets made of natural fiber were replaced with more complex, synthetic fiber to hold on to the more significant weight of caught fish. Mechanization further smoothed the process of industrial fishing. Power blocks became a part of purse seining and helped to haul up the nets. Drums were incorporated into longline fishing by the Japanese. By the 1960s, large trawlers traversed the sea to catch fish in their millions and even process them on board, allowing for longer trips. By the 1960s such vessels were operated by a handful of countries, namely the Soviet Union, East Germany, Japan, Poland, Spain and the U.K.

Types of Commercial Fishing

Commercial fishing operations are always looking for new ways to catch more fish while reducing the time and resources they expend. Commercial fisheries’ methods and tactics all prioritize the size of the catch over the well-being of the fish. Various types of fishing are used to catch fish from all ocean depths, from the surface to the seabed.

Fishing With Nets

Fishing with nets is the most common form of commercial fishing and is also the one that takes the most lives.

Purse Seine 

Purse seines function like purse drawstrings. This method is usually used to catch tuna fish. Purse seine nets are laid around a school of tuna in open water. While the top floats on the surface, the bottom sinks down, and once a good catch is confirmed, fishermen draw the net together to prevent fish from escaping. 


In trawling, a big net is attached behind a ship. The ship traverses water while the net collects fish on the way. Trawling can either be midwater or bottom, depending on how deep the net is in the water. 

In midway or pelagic trawling, the net is placed on the surface of open water and is mainly used to catch anchovies, tuna and shrimp. Bottom trawling catches fish from deeper into the water. In benthic trawling, fish are caught along the sea floor, while in demersal trawling, fish living close to the seabed are caught along with other sea life. 

Bottom trawling is like bulldozing the seabed, ripping it clear of flora and fauna that are vital to the oceanic ecosystem.


Gillnets are walls of netting designed to trap fish by their gill covers. The gillnets hang in the water and only allow the heads of the fish to pass through the mesh, capturing them by the side gills. Gillnets can be used in a way that mainly captures the species of fish intended to be caught — mostly tuna, salmon and swordfish. 

However, when the industry allows the nets to hang loose in the water instead of falling stiffly, they become “walls of death” for marine life and capture every fish, big or small, passing through the mesh. Deep drift gillnets were outlawed by the United Nations in 1989, but this method of placing miles of driftnets deep in the sea is still widely used illegally.

Fishing With Lines

Fishing with lines is a popular sport using fishing rods and hooks to catch fish. Unlike fishing with nets, this method cannot catch many fish simultaneously. However, commercial fishing gave this method an efficient spin, scaling up and increasing the number of fish caught using hook and line gear. 


Longline fishing positions miles of fishing line in the sea with hooks attached to one mainline, thus covering a large area and catching many fish. These hooks also catch other ocean animals who unwittingly attach themselves to the hooks. 

It is claimed that placing these lines deeper in the ocean can help untargeted fish caught on a hook to swim over the top; however marine animals face injuries and undue stress due to the hook piercing the body. 

Pole and Line

Pole and line is a labor-intensive method used to catch tuna and other midwater fishes one at a time, using a process of “chumming.” In this method, water is sprayed from the back of the vessel and bait fish (usually anchovies and sardines) are thrown into the water or attached to barbless hooks. 

Usually, this method uses live fish baits to create an illusion of a school of prey fish. When the target fish race to catch the baits, they get attached to the barbless hooks. The fish are then flicked up and tossed onto the deck, freeing the barbless hook in one single motion. This allows the fishermen to immediately put the hook back into the water, thus reducing the time involved in catching fish. 

Harvesting Shellfish

The primary reasons for catching shellfish are for food and ornamental products. Species of shellfish caught include clams, mussels, crabs, lobsters, shrimp, scallops and crayfish. Two standard methods are used to harvest shellfish.


This method collects clams and oysters. Heavy metal baskets are lowered onto the seabed and dragged to collect shellfish. These metal baskets have claws that collect shellfish, plowing into and damaging the seabed along the way. Not only do they cause significant harm to sea habitats, but they also catch other sea life as they go.

Traps and Pots

Traps and pots are widely used to capture a variety of shellfish. They are cages with bait suspended deep in the ocean. These cages are attached to a mainline to form a chain. Fishermen later collect the shellfish in the cages. 


In commercial shellfish diving, divers dive into the ocean to collect shellfish by hand. They collect oysters, pearls and scallops. Historically, people only used this method to collect shellfish for sustenance or famine food. However, commercial diving collects shellfish at an excess for profit. 

Why Is Commercial Fishing Bad for People and the Planet?

Commercial Fishing Is a Dangerous Job

Fishing is one of the most dangerous jobs in the United States. According to Bureau of Labor Standards data, fishing and hunting has the highest occupational fatality rate at 132.1 fatal injuries per 100,000 workers in 2020.

Because of the profit-oriented nature of commercial fishing, workers are under heavy pressure to maximize catch size within a certain period. They face various occupational hazards like falling overboard, faulty gear, slipping on watery decks and shipwrecks. 

Besides physical injuries, workers also face risks to their mental health owing to long working hours, excessive noise, and the nature of the work, which requires the routine killing of fish. 

Commercial Fishing Harms the Environment and Oceans

Fishing methods such as bottom trawling and dredging disturb the seabed and stir up sediments. When these sediments are resuspended in the water, they scatter and lower light levels, affecting oxygen production in the ocean. 

Commercial fishing contributes to algal blooms — proliferations of algae that can ultimately lead to “dead zones” in oceans, where marine life cannot survive. Oceans will release harmful chemicals if oxygen distribution keeps plummeting, including nitrous oxide, a greenhouse gas 300 times more potent than carbon dioxide. 

Commercial fishing is also responsible for fishing gear waste in the ocean. With many synthetic nets settling in the ocean, plastic pollution of the sea is becoming a significant concern. These nets and abandoned longline hooks continue to kill fish in the sea long after fishermen leave the area. 

Commercial Fishing Is Cruel to Animals

Unsurprisingly, an industry that views fish as a way to earn profits seldom thinks of their welfare. There is no escaping animal cruelty for the commercial fishing industry, which kills fish in their trillions

Fish caught from the ocean are left to suffocate and die on ship decks or are clubbed to death. In each scenario, fish are viewed as food, not sentient beings

Commercial Fishing Leads to Unnecessary Bycatch

Bycatch is the “byproduct” of commercial fishing — marine species that weren’t intended for capture are caught and left to die. Often, sharks and dolphins get caught along with other fishes. By the time fishermen identify them, they are incapable of surviving their injuries. 

Which Commercial Fishing Techniques Are Associated With Excessive Bycatch?

Gillnet fisheries, longline fisheries, purse seining and trawling account for most bycatch in commercial fishing. These methods focus more on catching a large number of fish than ensuring that they capture only intended marine species.

Where Does Most Commercial Fishing Take Place?

Just a few countries are responsible for most of the world’s seafood. 

China leads commercial fisheries production, followed by Peru, Indonesia, India, Russia, the United States and Vietnam. Together, these countries account for almost 49 percent of global fish catch.

What Are the Main Commercial Fishing Companies?

In 2017, roughly 11 to 16 percent of global seafood was caught by 13 commercial fishing companies, controlling the production of in-demand species. Some of the largest fishing companies in the world are Japan-based Maruha Nichiro and Nissui, and Mowi in Norway. In the U.S., Trident Seafoods is the largest seafood production company.  

As regards widely consumed fish species, the Thai Union Group and Dongwon Industries lead the world’s tuna production. Nutreco and Cargill Aqua Nutrition are the biggest farmed salmon companies.  

Does Commercial Fishing Make Money?

Recent data from the U.N.’s Food and Agricultural Organisation (FAO) show a first-sale revenue of $141 billion for capture fishing (rather than fish farming). Commercial fishing is one of the largest industries in the world in terms of profits. FAO’s data also shows that aquatic food is the most traded food product globally.

After all, the commercial fishing industry launches extensive marketing campaigns to demonstrate the necessity of seafood in our diets. 

What Are the Impacts of Commercial Fishing?

Commercial Fishing Is Reducing Shark Populations

The International Union for Conservation of Nature (IUCN) classifies many shark species as endangered. Besides being killed for food and medicinal purposes, sharks also become victims of excessive bycatch in commercial fishing. They are often trapped in gillnets or longlines or trawled onto ship decks.

Commercial Fishing Is Increasing Bycatch

One of the worst consequences of commercial fishing for marine life is bycatch. The commercial fishing industry is reportedly taking steps to reduce bycatch by altering the dimensions of nets and cages to capture only intended fish species. 

Yet despite these modifications, bycatch remains a severe problem. For example, smaller holes in trawling nets for capturing shrimp do not allow many species to escape. In longline fishing, even when bycatch species are identified, they are injured and in some cases, already dying. 

Commercial Fishing Is Killing Caribbean Coral Reefs

Coral reefs are underwater ecosystems formed by the growth and deposit of coral over time, creating large rocks. These reefs support about a quarter of the world’s marine species. The IUCN estimates that around a third of species of reef-forming corals are endangered globally. 

Commercial fishing activities significantly threaten coral reefs by modifying oceanic ecosystems. The industry excessively catches species necessary to maintain a healthy coral ecosystem. 

According to the IUCN, overfishing by the commercial fishing industry has led to the decline of species such as tuna in Caribbean waters and has killed many Caribbean coral reefs. If that is not enough, climate change and ocean warming further stress and destroy extensive coral reef ecosystems in the Caribbean.

Commercial Fish Farming Is Destroying the Environment

Commercial fish farming involves raising fish in controlled settings to sell for profit. Fish farming is an epicenter of disease outbreaks among fish, waste, pollution and excessive use of pesticides. All these features ultimately destroy the environment, affecting local species and communities dependent on the sea and its resources. 

What You Can Do

Most of the negative impact of the commercial fishing industry is because of the increasing demand for seafood. The best way to mitigate the impacts of commercial fishing is by reducing, or better, eliminating seafood from your diet. 

Reducing seafood demand is one way to hold the commercial fishing industry accountable. Recent investigations have uncovered various malpractices, including slavery and corruption, in the global fishing industry. Hence it is even more essential to take a stand against an activity that harms animals, the humans and the environment. 

You can also share information about the impacts of commercial fishing with your network. The more people are aware, the more hope we can have for the future. 

With the various threats that commercial fishing poses to oceanic vitality, it is time for the industry to step up and take action for the world, not just its own profits.

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