Overharvesting Of Marine Organisms

The term overharvesting, also known as overexploitation refers to harvesting of renewable resources to the potential level of diminishing return. The term is continuously used by ecologists to describe and refer to populations that are harvested to the point that is significantly unsustainable, provided their natural state of being subject to death and abilities for reproduction.

Overharvesting of marine organisms occurs mainly when marine species are being caught at a faster rate than they can naturally reproduce and replace themselves.

All living things including fish require resources to survive. Therefore, overharvesting or exploiting these resources for a long period can substantially deplete/reduce natural resources to the level where they are unable to reproduce and recover in a short time.

Overharvesting can significantly result in resource destruction, such as extinctions. However, according to ecologists, it is possible for overharvesting of marine species to be sustainable.

For example, when marine species are caught to a lower level of 15.5% of the pre-harvest biomass, and then change the harvest rate, the biomass can remain at that particular level. In this scenario, fishery is sustainable, but also remains exploited because the stock has been reduced to the level where the sustainable produce is less as expected to be.

Furthermore, fish stocks also collapse if their biomass decreases by more than 90% of their maximum previous biomass. For example, the Atlantic large marine fish stocks were severely overharvested in the late 1970s and early 1980s, leading to the abrupt collapse in 1992. Although fishing has ceased, the large marine fish stocks (cod) have dramatically failed to recover. Therefore, the significant absence of cod as the big predator in the different area has potentially led to trophic cascades. Indicates that about 25.5% of the world fisheries are now being overexploited to the level where even their current biomass is less than the point that increases their sustainable productions. These diminished fisheries can often recover if the rate of fishing is reduced until the stock of biomass returns to the most favourable biomass. At this particular point, exploiting/harvesting can be nearly recovered to the sustainable high yield.

Therefore, marine ecologists claim that overfishing is a significant threat to ocean ecosystems worldwide. Overfishing happens because marine species including fish are caught at a faster rate than they can naturally reproduce. Improved fishing technologies and high demand for fish have significantly led to overexploitation, causing many marine organisms to become endangered or extinct.

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