What is Overfishing?

Overfishing is the unsustainable harvesting of fish species at a rate faster than they can reproduce, leading to severe ecological imbalance. This practice not only threatens marine life but also jeopardizes the livelihoods of millions who rely on fishing. Are we doing enough to protect our oceans? Discover the ripple effects of overfishing and how it impacts us all.
M.R. Anglin
M.R. Anglin

Overfishing is when a particular type of fish is harvested so often and in such great numbers that the population of that fish is severely depleted, resulting in endangerment and potential extinction. This generally is the result of commercial, rather than recreational, fishing. Overfishing has implications well beyond marine life; it affects the human food supply, the fishing industry, and the environment.

The worldwide fishing industry may use many different types of technology in order to locate and catch fish. Some fishing liners can remain at sea for weeks and can freeze and process the fish they catch on board. This means that they only have to come to port when their stores are full. Fishermen on such ships are able to harvest more fish in a shorter period of time. The fishing industry can experience greater catches this way, and as a result more species can be overfished.

A commercial fishing boat.
A commercial fishing boat.

As the fish are reduced in number, fishermen may use smaller nets trying to catch smaller fish. The result is that younger fish are often caught. Catching young fish can be problematic if they are caught before they are able to breed and contribute to replenishing the population. The use of nets can also lead to bycatching, which is the trapping of non-target species. For example, porpoises can get caught in salmon nets, and dolphins can get caught in tuna nets.

Wild salmon are uncommon in rivers in many places due to overfishing.
Wild salmon are uncommon in rivers in many places due to overfishing.

Overfishing can also affect species that fishermen never catch. If one type of fish is eliminated, the entire ecosystem can collapse. For example, cod fish prey on herring. If a fisherman harvests all the herring in a particular area, then the cod starve. Overfishing can also affect other non-marine animals, such as birds, that rely on fish for food.

Overfishing leads fishermen to net younger fish, and this can exacerbate the problem.
Overfishing leads fishermen to net younger fish, and this can exacerbate the problem.

Not only can overfishing have an impact on marine life, it can also have an impact on human life. An example of this is an incident that occurred in Newfoundland, Canada in 1992. At the start of the fishing season, the cod that usually frequented the water did not appear. Many of the people who depended on catching the cod lost their livelihood.

The problem of overfishing is one that could result in serious economic and environmental implications for the world at large. Governments worldwide have conducted studies and enacted laws to reduce or outlaw overfishing. Advocate groups exist that encourage consumers to reduce the demand for overfished species by purchasing fish that are harvested in a sustainable manner.

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Discussion Comments


In Lake Victoria in East Africa the nile perch stock is declining at the alarming rate.


@titans62 - We actually got off on a tangent about overfishing in one of my classes recently, and my teacher was telling us about some of the ways that places are dealing with the problem. One thing that a lot of countries are doing is making fishing quotas with permits. Basically, a country will decide how many fish can be safely caught without destroying the ecosystem. Then, they will make that number of permits and distribute them to registered fishermen who can catch the number of fish they have permits for. If someone has too many or too few, they can buy and sell them from other people. If you get caught not following the rules, there is a huge penalty like a fine and possibly having your fishing boat taken away.

We didn't really talk much about overfishing the oceans and how to regulate it, but it seems like it would have to be a global agreement between a lot of the major countries you mentioned. If 5 countries decide not to overfish, but a 6th jumps in and takes all the extra fish, it isn't really fair. Maybe the UN could have some sort of involvement with it.


Some of the other overfishing species that I don't think people give a lot of thought to are the sharks. I was reading an article not too long ago that in China, shark fin soup is a delicacy and is a way for people to show their economic status. Basically, the get the fins, they just go into the ocean and catch sharks and then cut the fins off of them and throw the rest of the body back into the ocean where, obviously, the shark dies.

As I'm sure it's not hard to imagine, sharks are a huge part of the ocean ecosystem and keep a lot of other species' populations in check. Without as many sharks, they are finding that a lot of other species like rays are getting overpopulated and destroying the other species that they feed on.

Honestly, I don't know if there is any way to end overfishing. It seems like the only way it will stop is when there are no fish left to catch.


@jcraig - Unfortunately, overfishing issues are a huge problem that probably don't get the attention they deserve. Like you and the article mention, tuna and salmon are often considered to be overfished. Even though there are still plenty of fish to buy, that's not to say that the global fish populations aren't rapidly decreasing. Plus, you have the other problem of losing a lot of important species in the ecosystem.

I would say overfishing is less a problem for specific counties, and would say it is more caused by certain countries. You're right about East Asian countries being huge fish-driven countries, but when you think about it, all the fish in the oceans are shared by every other country, because there is no way to regulate international waters. Because of that, it's usually a combination of all the developed fishing countries that cause the problem together. So besides Asian countries, the US, Canada, Iceland, and other European countries add to the overfishing problem.


I didn't know that overfishing could be such a problem. Besides something like cod that the article mentions, what are some of the other types of fish that are harvested too much? The article talks about tuna and salmon, but doesn't specifically say if they are overfished. It seems like there is always plenty of all the different types of fish any time you go to the store, so is overfishing really that big of a problem?

I would also guess that overfishing in the United States is less of a problem than in some other places that rely more on eating fish like East Asian countries. If overfishing really is a big problem, what types of laws are in place to stop it from happening, and are they effective?

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    • A commercial fishing boat.
      By: Paul Hamilton
      A commercial fishing boat.
    • Wild salmon are uncommon in rivers in many places due to overfishing.
      By: Witold Krasowski
      Wild salmon are uncommon in rivers in many places due to overfishing.
    • Overfishing leads fishermen to net younger fish, and this can exacerbate the problem.
      By: B. Wylezich
      Overfishing leads fishermen to net younger fish, and this can exacerbate the problem.