Environmental Impacts Of Overfishing

Although it was initially assumed that the ocean has an abundant and limitless supply of food resources, the destructive impacts of fisheries have now come to light. It is becoming clear from decades of fishery activities that these practices are highly detrimental to the aquatic environment, be it freshwater or marine. Furthermore, fisheries are noticing declines in the abundance and variety of the fish and invertebrates that are harvested. This is not only due to overexploitation but also physical and ecological damage to the fishery environment (NOAA, 1998). In fact, fisheries or the commercial harvesting of fish and shellfish is by far the most destructive force in the oceans today. The environmental impact of which may vary from being

(2003), overfishing refers to reducing a population stock to a threshold level below which the stock can recover from. It means that the rate of fishing mortality may be greater than the rate at which the population can reproduce, this greatly affects the sustainability of harvesting the fishing stock because continuing to overfish in such a manor hinders the population’s ability to recover and may become depleted or locally extinct. This leads to a significant reduction in the biomass of a population (FAO, 2015).

Overexploitation can lead to the harvesting of the older, larger, mature individuals. This greatly affects the spawning ability of the stock as a whole as the reproducing individuals are removed, leaving behind the smaller, immature individuals that are not yet capable of reproducing and thus recovering the biomass lost through fishing (NOAA, 1998). Fisheries target areas of the sea where fish are abundant such as continental shelves and seamounts. Usually the fish in these areas are susceptible to overfishing because they are slow-growing and take a long time to recover (OSPAR Commission, 2008). Overfishing also changes the population dynamics of a target species, altering the sex ratio, age structure, and genetic variability, etc. (Garcia et al,

Fishing gear such as trawls and dredges are dragged along the benthos which damage and break living and non-living structures along the bottom of the sea/river/lake. The benthos supports its own ecosystem and the supporting structures are central to creating niche habitats for many bottom dwelling animals (NOAA, 1998). Disturbance of the bottom can also cause displacement of burrowing animals and animals that live in or on the sandy bottom. Sandy bottoms may settle after it has been dredged, however issues of disturbed sediment and increase in particulate matter can affect the amount of sunlight that reaches the associated seagrasses and corals, thereby disturbing their growth (Garcia et al,