Overfishing: The Decline in Fish Population

Written by: Ng Shi Yi, Charlene (1SB6) and Syed Nabil Bin Syed Hassnor (2AD2)
Edited by: Sitinur (2SB4)

[Characters from the hit Disney-Pixar film, ‘Finding Nemo’]

Imagine you are a fish: every day is an exciting new day to swim alongside your school of friends. However, more recently, throughout the day, you face the dread of hearing the increased drumming of the motor of the passing fishing ships and the swoosh of fishing nets being cast over the ocean. You hear your heart palpitating as you pray that you aren’t part of the fishes being caught by these fishermen. You swim about in a frenzy, hoping to be lucky enough to escape the clutches of death yet again.

As the groan of the motor of the ship fades away, your heart drops as you hear, yet again, that some of your friends and family are taken away by the fishermen. You mourn over the fact that you will never see them again, but yet you sigh in relief, glad that you aren’t part of the hoards of fishes being taken away. However, the excessive fishing has only contributed to a dwindling population of fishes left in the ocean.

The causes of this depletion of fish in the ocean stem from excessive fishing by humans. This excessive fishing can result in fish being removed at a faster rate than the fishes can replenish naturally resulting in a decrease in the population of fish in that area. This is called overfishing.

[A figure showing the estimated amount of fish and other seafood production across the globe. Image: Our World in Data]

Factors contributing to overfishing are illegal fishing, fishing subsidies and increasing consumer demand, and more.

1. Illegal and poorly-regulated fishing. 

Some of the worst ocean impacts are caused by pervasive illegal fishing, which is estimated at up to 30% of catch or more for high-value species. With experts estimating illegal, unreported, and unregulated (IUU) fishing nets criminals up to $36.4 billion each year, these illegal catches threaten marine biodiversity and the population of fishes in the sea (Source: World Wildlife Fund). Illegal fishing methods such as blast fishing in countries such as SEA countries like Indonesia through explosives and cyanide, and these account for about 20% of the world’s catch (Source: Earth Eclipse). Moreover, illegal fishing does not only affect the population of fish, but their habitat as well. 

2. Subsidies to the fishing industry to offset the costs of doing businesses.

Because of the influence of these subsidies, there would likely be a surplus of fishing vessels and skewing of production costs so that fishing operations can continue to operate even when not necessary. For example, today’s worldwide fishing fleet is estimated to be up to 2.5 times the capacity needed to catch what we actually need (Source: World Wildlife Fund).
3. Increasing consumer demand leads to increased fishing.

[In just 57 years, fish consumption has increased by over 10 kg per capita. Image: FAO North America.]

With a growing population and affluence coupled with economic aspiration of fishing industries, this has led to increased output by fisheries to keep up and match consumer demand. In most cases, overfishing is a natural reaction by the fishing industry to increase supply to meet the increased demand (Source: World Wildlife Fund).

Overfishing, as the term negatively connotes, can result in widespread economic and environmental disasters. Even the process of modern fishing could severely harm the ecosystem. This is because most modern fishing gear used in commercial fishing catches marine life indiscriminately; it is not able to differentiate between the targeted and non-targeted catch. While unwanted by-catches such as sharks, turtles and dolphins are often dumped back into the sea, they usually do not survive having been exposed to a sudden change of atmosphere. As a result, these lead to degraded ecosystems, where an imbalance in the fish population could negatively affect the food web, resulting in the loss of other important maritime species such as corals and sea turtles.

Trawlers are the most commonly used commercial fishing gear. These drag fishing nets along the bottom of the seabed, trapping all kinds of marine life, including immature organisms or unwanted species. This is similar to drift (or gill) nets, which are nets that are left to drift feely in seas trapping almost everything in their path.

[Images showing how drift/gill nets and trawlers work. Images: World Ocean Review]

Dredging is also a rather common commercial fishing method. It involves the use of dredges, which scrape the seabed, destroying coral reefs and organisms living on the seabed.

[An image showing how dredging works. Image: Montrose Port Authority]

Cyanide fishing is also an extremely harmful fishing method, and this is usually done to catch fish for pets or display at aquariums! Cyanide fishing involves the use of cyanide, a poison, being squirted into the water around coral reefs. The cyanide would stun fish, allowing fishermen to then capture the fish easily. The use of explosives such as dynamite are also used to stun and catch reef fish. As aforementioned about the effects of modern fishing methods, not only do these harm the targeted fish population, but also all the other organisms in the ecosystem as well as the surrounding areas. Thankfully, this fishing method is illegal in many countries (Source: Hakai Magazine). 

Apart from these environmental impacts, overfishing could also lead to a severe economic crisis in affected countries; a decrease in food and economic security. Because of the increasing demand for fish with an increase in the world population, more businesses and jobs are dependent on the gradually depleting stocks of fish. 

The importance of fish are as follows (Source: World Wildlife Fund):

  • Fish ranks as one of the most highly traded food commodities and fuels a $362 billion global industry.
  • Many developing countries depend on the fishing industry for jobs.
  • Nearly half of the world population relies on fish as one of the major sources of protein.

With these in mind, the continuous depletion of the fish population could mean the continuous depletion of coastal economies and jobs, as well as a major source of protein for the world population. The high demand also breeds the tendency of overexploitation of commercial fishing, further worsening environmental degradation.

Overfishing has caused extremely detrimental effects to our world, and it is likely not going to get any better unless more regulations or measures are in place.

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