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25 Effects of Overfishing – Risk – Danger

by Dwi Purwaningsih

Marine offers its beneficial richness in which human can take advantage of, for example is the population of fish it offers. Thus, fishing has been a beneficial activity in which fishermen catch fish in the open sea as commodity. This activity has going on for years until a certain effect is brought up called overfishing.

Basically overfishing means catching too much fish to the point it reduces fish population and prevents sustainability of fish, making it one of threats to marine ecosystem.

Overfishing occurs when fishermen take too much of the adult fish of any kind. Fishing that is on the risk of doing it overly is fishing for commercial purpose by a company. Individual fishing will hardly contribute an effect. To be more aware how this action affects marine ecosystem, here are 25 effects of overfishing.

1. Fish Population Decline

Most fish caught for commercial purpose are adult fish since they are bigger and have more flesh. However, adult fish are also the one responsible for breeding. If fishermen keep catching the adult ones, there will be lesser chance for the species to reproduce. If they cannot reproduce, it means the population will decrease. The fatal consequence will be extinction of certain fish species.

2. Imbalance to Marine Ecosystem

In every ecosystem, there is food chain in which animals in their own levels contribute to balance each other’s population. If there is less to none fish found, then there will overpopulation of species in lower level of food chain, while the predator of fish will be in the danger of extinction because of lack of food. Thus, the nature will lose balance and odd occurrence that will disrupt nature may happen as causes of ocean destruction.

3. Overpopulation of Plankton

Since fish main food is usually plankton, if population of fish decrease, the plankton will have greater chance to overpopulate. There will be cases when the sea is contaminated or loses the clearness due to plankton filling up. Any activities in the sea will be disturbed if the plankton and some types of ocean parasites dominates the sea. Plankton is also less beneficial for human, making any industries relying on sea having even more trouble to get rid of the overgrown plankton.

4. Fish Extinction Leading to Malnutrition

Fish has much beneficial nutrition for human’s health. It has omega, protein, and vitamin that can support the whole metabolism. The effect of overfishing in the long term is the decrease of fish consumption because fish will be hard to find once they no longer can produce normally, thus human cannot eat fish as frequent as the wish to do. Another related, probable is fish can be a luxury poor citizens cannot afford, in which it will lead to global malnutrition.

5. Uncontrolled Growth of Other Species

When overfishing includes predator that usually only prey for certain species of fish, other species that prey on beneficial fish may grow in spurt. For example, rays prey on shellfish and other edible fish while shark prey on rays. If shark becomes one of the victims of overfishing, rays whose preys are beneficial to human will make the commodity stock decreases. If it happens, it means less edible fish for human.

6. Extinction of Other Species

Opposite to the previous effect, some untargeted marine species including smallest mammal in the world will also die out because there are less fish to prey on or there are too many predators left who prey on them. This is certainly uncalled for especially since fishermen only target certain species, leaving the untargeted species die out because of the imbalance of nature.

7. Low Level of Biomass

Biomass is an organic material coming from animals and plants used as energy source. It is considered to be a renewable energy source. However, if overfishing reduces certain species drastically, it means there is less material for biomass. As consequence of the lessening of biomass, it means lower level of energy source. Some parts of the world depend on biomass energy, thus may cause energy crisis in the long run.

8. Future Economical Decline

If overfishing occurs and fish commodity starts to depopulate, it means there will be less fish to catch on. Fish has been one of the biggest sources for economic development. Thus, if there is none to catch, the market of this commodity will decline, leading to a downgrade in economical condition. Some fishermen will lose their jobs; some of the workers in marine industry may become unemployed. Hence, the effect of overfishing can be tremendous.

9. Reduction in Marine Biodiversity

As some marine species may be exposed to the risk of getting died out, the biodiversity of marine ecosystem will decline. A sea that is used to have plenty species will no longer be as rich as before. If this occurs, there balance of nature may change, and it will indirectly affect human too. For example, a fish species is responsible to clean out the sea, but if they extinct, they will not be able to clean it and get rid of hazardous substance from sea.

10. Premature Reproduction

Overfishing disrupt the delicate nature of marine ecosystem. As a result, odd occurrence may occur. There are cases where the reproduction of certain species is being prematured. This is because the remained adult species are forced to reproduce more in order to make up the lost population of the fish. Such occurrence definitely is not healthy for ecosystem, the prematured species will not last long and die out easily.

11. Mutation of Certain Species

While premature reproduction is one of the effects of overfishing, some species may undergo mutation in which they do not grow normally because the balance of nature is disrupted. Some fish get smaller than the usual size or losing some of their body part. If this occurs, mass mutation will cause another problem in which the fish may no longer edible.

12. Decline of Nutrient Recycling

Some fish species release certain chemical to the sea that function as nutrient to other marine species. Fish are commonly known to release nitrogen phosphorus which are some of the nutrients needed in the marine ecosystem. If overfishing occurs, the targeted fish will not be able to contribute to marine nutrients. In return other untargeted species may get malnutritioned and die out easily.

13. Decline in Coral Population

Another effect that is often overlooked by people is the fact that overfishing unintentionally destroyed the habitat of other marine species. Some of the ways used for fishing includes material that has mass damage to not only the targeted fish, but also its habitat. For example, the use of bomb fishing caused damage to the coral.
Coral is a delicate species in which even one touch can affect its life. Therefore, if overfishing keeps occurring, the population of coral will decline. If coral population decline, it means some marine species lose their habitats as well. (Related to Destruction of Ocean Habitat).

14. Sea Pollution

Certain species in the sea act as cleaner by eating some of the water pollutants found in other species. If the species are targeted for fishing, it means there will be no longer control of water pollutant such as plaque and microorganism. If the pollutants are uncontrolled then the sea will be polluted. Polluted sea will cause many negative effects such as decline in oxygen, mass poisoning, and many more.
The increasing sea pollutants will also affect human. Human who caught fish from polluted sea is exposed to food poisoning or allergy caused by the all the pollutants found in the sea. To know more abot water pollution, read Ocean Pollution.

15. Lack of Oxygen in The Sea

When species of untargeted commodity overgrown themselves such as plankton, they will cover the surface of the sea. As a result, oxygen will find it hard to enter the depth of sea as well as sunlight. If oxygen cannot enter the sea, species who depend their lives on oxygen will become deoxygenated and eventually die out.
Thus, as insignificant as it seems, overgrown population of certain disadvantageous species should be getting rid of. If it keeps occur there will be even more decline to the untargeted species, further destroying the food chain and whole marine ecosystem.

16. Disrupted Balance of Marine Life

Because some of the marine species are in the brink of extinction, the delicate nature of marine life will be highly affected in negative way. Sea plants will not be able to reproduce well if they are not helped by certain species. The disrupted food chain will change the existing one to a declined changes.

Other Effects

  • Exposure to dangerous species as result of trying to find substitute to extinct species.
  • Mass extinction of marine species
  • Uncontrolled sea waves as less coral support the sea from getting wiped out.
  • Smaller supply for fish commodity
  • Sea species experience amputation resulting from stress.
  •  Degraded habitats of marine species
  • Climate change resulted from disrupted ecosystem.
  • High level of salt causing dead sea
  • Lesser opportunity of benefiting from the already scarce marine species.

Overfishing is often overlooked as the demand of fish for consumption and commercial purpose increased significantly. However, the effects of overfishing is serious and something to be taken into consideration for the government to regulate fishing activity. Especially since the effects of overfishing impact not only to the targeted fish but also widely affect species including human.
Regulations and awareness in general are needed in order to protect the precious sea. Indeed, there are 25 effects of overfishing.

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