Environmental impact of fishing
According to a 2019 FAO report, global production of fish, crustaceans, molluscs and other aquatic animals has continued to grow and reached 172.6 million tonnes in 2017, with an increase of 4.1 percent compared with 2016.
[2] There is a growing gap between the supply of fish and demand, due in part to world population growth.
The latter is largely caused by plastic-made fishing gear like drift nets and longlining equipment that are wearing down by use, lost or thrown away.
[5][6] The journal Science published a four-year study in November 2006, which predicted that, at prevailing trends, the world would run out of wild-caught seafood in 2048.
The scientists stated that the decline was a result of overfishing, pollution and other environmental factors that were reducing the population of fisheries at the same time as their ecosystems were being annihilated.
[14] A 2005 report of the UN Millennium Project, commissioned by UN Secretary-General Kofi Annan, recommended the elimination of bottom trawling on the high seas by 2006 to protect seamounts and other ecologically sensitive habitats.
In mid-October 2006, United States President George W. Bush joined other world leaders calling for a moratorium on deep-sea trawling.
The practice has shown to often have harmful effects on sea habitat and, hence, on fish populations,[15] yet no further action was taken (Vivek).
Overfishing can occur in water bodies of any sizes, such as ponds, wetlands, rivers, lakes or oceans, and can result in resource depletion, reduced biological growth rates and low biomass levels.
[19] The ability of a fishery to recover from overfishing depends on whether its overall carrying capacity and the variety of ecological conditions are suitable for the recovery.
Bycatch, the collateral capture of unintended species in the course of fishing, is typically returned to the ocean only to die from injuries or exposure.
Overfishing and pollution of the oceans also affect their carbon storage ability and thus contribute to the climate crisis.
Moreover, policy of minimum landing size, based on the idea that it spares young fishes, have many negative impacts on a population by selecting slow growth individuals.
[35][36] Unable to swim effectively, they sink to the bottom of the ocean and die of suffocation or are eaten by other predators.
[52][54] Using technological or mechanical innovations such as marine debris-clearing drones can further serve to reduce the amount of debris within oceans.
[22] To increase the effectiveness of catch and release fishing and mitigate its negative impacts, species-specific guidelines are required.
[60] One method for increasing fish population numbers and reduce the severity of adverse environmental impacts and ecological disturbances is the use of fisheries management systems.
[63] However, many scientists highlight that those fish populations are declining due to the fact that they have not been assessed and therefore adequate fisheries management techniques have not been applied.
[60] Since these fishermen are not guaranteed compensation for part of the quota, they tend to resolve to the method of harvesting as many fish as possible.
[60] This competitiveness among fishermen and their fleets leads to the increased use of harmful fishing practices, extremely large harvests, periods of reduced stocks and the eventual collapse of the fishery.
[60] In that case, the percentage of collapsed fisheries in 2003 was projected as 9%, which remained fairly stable for the rest of the experiment's time period.
[60] Despite the projected success of the ITQ-managed fisheries, the results of this study may not be a completely accurate representation of the true impact of right-based management.
[60] This is due to the fact that the data used to create these results was limited to one type of catch share and that the true effects of ITQs can only be assessed if social, ecological and economic factors were also considered.
[65] Opting for a different hook design or bait type can make fishing practices less dangerous and lead to less bycatch.
[66] Using 18/0 circle hooks and mackerel for bait has been shown to greatly reduce the amount of leatherback sea turtles and loggerheads caught as bycatch.
[61] Many governments and intergovernmental bodies have implemented fisheries management policies designed to curb the environmental impact of fishing.
[67] Fish farms are usually located in coastal waters and can involve netpens or cages that are anchored to the sediment at the bottom.
[67] As many fisheries have been heavily depleted, farming profitable and commonly consumed fish species is a method used to supply larger quantities of seafood for human consumption.
[68] This can be problematic because the small fish used for the production of fishmeal also serve as food for predators living outside the enclosures.
[71][72] As a result, the primary benefits arising from the implementation of this type of management effort include positive impacts towards habitat protection and species conservation.
