The vessels employed by the industry can be over feet in length, and have the capacity to catch hundreds of tons of fish a day. The pure ability of the industry to catch so many fish a day makes it a significant factor towards the decline of sustainable fisheries. Some of these fish include Bluefin tuna, Atlantic halibut, Atlantic cod, Atlantic salmon, Chilean sea bass, Red snapper, Yellowfin tuna, and more-- the list contains 22 marine species.
Many of the practices and methods of the commercial fishing industry also threaten ocean environments. A common practice used by fishermen is called trawling , in which a net is dragged along the ocean floor.
This disturbs the bottom of the seabed and often drags up plants and coral populations with it that provide a vital importance to maintaining the balance of marine ecosystems. Another large threat from the commercial fishing industry is the lost or abandoned fishing gear that is disposed of within our oceans. A report by Greenpeace found that , tons of fishing gear accounts for the waste in our oceans each year, which is the equivalent of the weight of 50 thousand double-decker buses.
Fishing nets actually account for 86 percent of the large plastics within the Great Pacific Garbage Patch. Possibly the greatest ethical and environmental concern to come from the commercial fishing industry is bycatch.
Examples of bycatch include dolphins, whales, sea turtles, and seabirds that become hooked or entangled in fishing gear. Sustainable fishing practices arose due to the bycatch problem many felt uncomfortable with, which was estimated to kill , whales and dolphins and , turtles globally each year. To keep up with the increasing global demand for seafood, aquaculture has increased in popularity to yield more fish.
These wastes are largely nitrogen and phosphorus-based , which causes oxygen depletion in coastal environments and a net loss of marine productivity in certain coastal areas. The included use of antibiotics, pesticides, and added drugs have the potential to destroy the marine environments being used for fishing, causing additional harm to our oceans. These antibiotics can either have direct impacts on sea life when introduced to the natural environment or can cause disease resistance to develop which can be problematic further down the line.
Gillnets are staked to the ocean floor and entrap many animals unintentionally. The collective toll from these practices is staggering. Over the past twenty years, an estimated 85, sea turtles have been killed as bycatch. Animals like albatrosses and sea turtles that are long-lived and slow to reach maturity are particularly impacted by these threats and many populations have declined precipitously over the past few decades.
As with the other impacts from fishing, consequences of bycatch are often far-reaching as species become functionally extinct in many areas. For example, leatherback turtles are major predators of jellyfish, capable of consuming more than jellyfish in a single day.
This has made the waters dangerous for swimmers in some places that rely on tourism as a revenue source and can also prevent the recovery of depleted fish stocks. Green sea turtles and manatees, which are commonly victims of bycatch, also demonstrate the ecological complexities that can occur after the removal of important functional species. These animals are herbivores that graze in seagrass beds.
In these habitats they are important because their constant grazing keeps the grass at a healthy level, contributing to nutrient cycling and preventing disease outbreaks from spreading through the grass beds.
When this happens, biodiversity declines as these habitats can no longer support a wide range of marine life. In recent years, the consequences of fishing have increasingly become the source of research interest. Much of this has been prompted by the collapse of commercially valuable fisheries, as well as the threat of extinction to many animals.
For some species, like bluefish and flounder in the mid-Atlantic, implementing catch limits has been successful in bringing back depleted stocks. For other species like the Atlantic cod, however, such regulations have not resulted in a rebounding of the population. Research has also focused on new methods of fishing that are less destructive. For example, studies on diver harvesting of oyster showed that the technique was less damaging to the structure of the reef than traditional methods like dredging.
Whereas the latter method indiscriminately picks up all oysters, including those that are dead on the reef, diver harvesting is more selective and only collects those that are commercially valuable. The practice was also shown to increase the amount of oysters harvested per unit time of fishing. There has likewise been much investigation into techniques that reduce fisheries bycatch. For example, studies on longline hooks have shown that certain hooks do not get stuck in the mouths of sea turtles, which reduces their risk of capture.
Research on turtle light perception has shown that certain light frequencies are not visible to turtles, but are still attractive to swordfish. For crab pots, bycatch reduction devices are tiny plastic rings that are attached to the openings. These make the openings smaller so that blue crabs can still get in while keeping terrapins out.
One of the largest success stories of bycatch reduction has been the use of turtle excluder devices TED in shrimp trawlers. In the Gulf of Mexico, bycatch of Kemp's ridley turtles in shrimp trawlers was cited as a major factor in declines of the species. The TED is a large grate that is attached to the inside of the net and an opening in the net is placed next to it. Shrimp easily pass through the grate, but turtles cannot get through it.
When they come into contact with the grate, the opening in the net provides a way out and the turtle can leave the net unscathed. Reduction in bycatch from using this device has led to significant recovery of Kemp's ridley turtles in the Gulf of Mexico. Gaining International Experience in Environmental Science. Birds as Environmental Indicators. Environmental Consequences of Fishing Practices. This culling preference is different from commercial or subsistence fishing, which aim to catch as many fish as possible, but not necessarily the largest individual member of a species.
The paper looked at the global state of management regulations for recreational fishing and found that only 86 nations define recreational fisheries in their national fisheries-management legislation. Another major issue with recreational fisheries management boils down to numbers — or lack of them. In most places nobody knows exactly how many fish are caught. They consolidated information from a variety of sources and built a bigger picture.
Potts points out that this kind of formulation can cause complications. Even though the results are estimates, they suggest two potentially troubling trends. First, all recreational fisheries catch is significantly increasing in developing-world nations, especially in Africa and South America.
For example, the number of recreational fishing licenses in Brazil jumped from , in to more than , just two years later. Second, recreational fisheries targeting sharks and rays are on the upswing worldwide. Additionally, some on social media claimed that this paper was proof that all recreational angling needed to be shut down, which was not a recommendation issued by the paper. A post shared by fishingfanss on Mar 10, at pm PDT.
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