Overfishing aff inherency
Bio-D General Destructive Practices
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- Many common fishing practices hurt the fragile ecosystems by choosing profit over the ecosystems
Bio-DGeneral Destructive PracticesOverfishing threatens biodiversity – fish can’t reproduce and the ocean ecosystems are being tampered with causing them to changeHauge et al. 9, Hauge, Kjellrun H., Belinda Cleewood, and Douglas C. Wilson. jellrun Hiis Hauge, Institute of Marine Research, Bergen, Norway; Douglas Clyde Wilson, Senior Researcher and Research Director at Innovative Fisheries Management, Aalborg University; Belinda Cleeland, project officer, IRGC. "Fisheries Depletion and Collapse." (n.d.): n. pag. IRGC. International Risk Governance Council, 2009. http://irgc.org/wp-content/uploads/2012/04/Fisheries_Depletion_full_case_study_web.pdf Web. 1 July 2014. CS Overfishing poses serious risks as the loss of marine biological diversity can have serious consequences for the stability of marine and coastal ecosystems. Biological extinction from a directed fishing effort is extremely rare because economic extinction (i.e., the fish becoming too rare to fish profitably) usually happens well before biological extinction. However, overexploitation of the target fish population can lead it to become depleted to the point where it cannot recover because the depletion of the fish stock often involves other ecological changes. Fishing can also change trophic relationships through changing the relative abundance of predators, prey, and competitors as well as the genetic make-up of populations [ICES 2006]. Research on the Scotian Shelf in Canada has documented a vast general change in the ecosystem that seems to have been driven by the removal of a huge number of fish [Choi et al. 2004] and resulted in the emergence of a completely different set of dominant species, mainly invertebrates. The failure of the Northern cod stock to recover following its depletion (in spite of a sustained fishing moratorium) can be explained by overfishing, the effect of which was amplified by environmental changes, which altered the ecosystem structure [Frank et al., 2005]. Similar conclusions can be drawn in the cases of the Black Sea [Daskalov, et al., 2007] and the Baltic Sea [Möllmann et al., 2008], and Daan et al. [2005] discuss whether the changes in the North Sea fish community were caused by overfishing . Other suggested effects of overfishing are evolutionary effects [Jørgensen et al., 2007] and changes in fish behaviour, for example migration patterns, due to loss of learning from older fish, which have basically beenremoved from the population [Fernö et al., 2006]. Overfishing may also further amplify any effects brought about by global warming on the ocean environment, the structure of its ecosystems and of invasive species. Loss of biological diversity and changes in ecosystem stability can also result from bycatch of non-target species. Bycatch2 , especially in mixed fisheries that target several stocks, is perhaps the single greatest fisheries management challenge. The problems of catching undersized fish can also be a great problem. For example, even when the depleted North Sea cod stock manages to produce abundant offspring, the majority is discarded at a very early age and only a small percentage of the cod manage to reach maturity to produce more offspring [ICES, 2008]. Bycatch problems extend to marine mammals, sea turtles, seabirds and sharks. Fishing activities can also damage marine habitats. Some types of fishing, intensive trawling in particular, cause damage to the sea bed and may reduce the number of marine fauna living in the deep seas or in the benthic zone (sediment and sub-surface layers of sea-beds) by between 20- 80% [Nellemann et al., 2008:10]. Industry practices like trawling, cyanide, dynamite, and ghost fishing are environmentally destructive and cause irreparable damage to local ecosystems.WWF No Date (World Wide Fund for Nature, “Fishing problems: Destructive fishing practices”, http://wwf.panda.org/about_our_earth/blue_planet/problems/problems_fishing/destructive_fishing/, Date Accessed: 063014) Many fishing practices are extremely destructive to delicate habitats - particularly vital fish breeding grounds like coral reefs and seagrass meadows. For example: Bottom trawling: Industrial trawlers once avoided coral reefs and other rocky regions of the ocean floor because their nets would snag and tear. But the introduction of rockhopper trawls in the 1980s changed this. These trawls are fitted with large rubber tires or rollers that allow the net to pass easily over any rough surface. The largest, with heavy rollers over 75cm in diameter, are very powerful, capable of moving boulders weighing 25 tonnes. Now, most of the ocean floor can be trawled down to a depth of 2,000m. These trawls - whose use is now widespread - are extremely damaging. In an experiment off Alaska, 55% of cold-water coral damaged by one pass of a trawl had not recovered a year later. Scars up to 4km long have been found in the reefs of the north-east Atlantic Ocean. And in heavily fished areas around coral seamounts off southern Australia, 90% of the surfaces where coral used to grow are now bare rock. When covered with marine life, these seabed areas provide habitat for juvenile fish and other species. Like removing forest, removing this cover decreases the area available for marine species to live and thrive in. Cyanide fishing: In this technique, fishers squirt sodium cyanide into the water to stun fish without killing them, making them easy to catch. Cyanide fishing on coral reefs began in the 1960s to supply the international aquarium trade. But since the early 1980s, a much bigger, more profitable business has emerged: supplying live reef fish for the restaurants of Hong Kong, Singapore, and, increasingly, mainland China. Some 20,000 tonnes of live fish are eaten annually in the restaurants of Hong Kong - and for every live fish caught using cyanide, a square metre of their coral reef home is killed. Dynamite fishing: In this technique, dynamite or other explosives are set off under water. The dead fish floating to the surface are then simply scooped up. The explosives completely destroy the underwater environment, leaving it as rubble. Dynamite fishing has contributed to massive destruction of, for example, Southeast Asian coral reefs over the past 20 years. Ghost fishing: Ghost fishing occurs when fishing gear is lost or abandoned at sea. The gear can continue to catch fish, dolphins, whales, turtles, and other creatures as it drifts through the water and after it becomes snagged on the seabed. When driftnets were used on the High Seas, an estimated 1,000km of ghost nets were released each year into the North Pacific Ocean alone. Although the current contribution of ghost fishing to bycatch is unknown, it is likely to have a large impact. One survey estimated that a quarter of the rubbish on the bottom of the North Sea is fishing nets, while fishers speak of a dolphin and turtle graveyard among the nets that drape the cliffs of Cape Wessell, Northern Australia. Popular fishing methods devastate non-target species and attempt to exploit new resources at the expense of undiscovered marine life and habitats.Sielen, 2013 (ALAN B. SIELEN is Senior Fellow for International Environmental Policy at the Center for Marine Biodiversity and Conservation at the Scripps Institution of Oceanography. He was Deputy Assistant Administrator for International Activities at the U.S. Environmental Protection Agency from 1995 to 2001. “The Devolution of the Seas”, Foreign Affairs, 00157120, Nov/Dec2013, Vol. 92, Issue 6, EBSCOHost, Date Accessed: 063014) The Consequences of Oceanic Destruction TEACH A MAN TO FISH-THEN WHAT? Another cause of the oceans' decline is that humans are simply killing and eating too many fish. A frequently cited 2003 study in the journal Nature by the marine biologists Ransom Myers and Boris Worm found that the number of large fish -- both open-ocean species, such as tuna, swordfish, and marlin, and large groundfish, such as cod, halibut, and flounder -- had declined by 90 percent since 1950. The finding provoked controversy among some scientists and fishery managers. But subsequent studies have confirmed that fish populations have indeed fallen dramatically. In fact, if one looks back further than 1950, the 90 percent figure turns out to be conservative. As historical ecologists have shown, we are far removed from the days when Christopher Columbus reported seeing large numbers of sea turtles migrating off the coast of the New World, when 15-foot sturgeon bursting with caviar leaped from the waters of the Chesapeake Bay, when George Washington's Continental army could avoid starvation by feasting on swarms of shad swimming upriver to spawn, when dense oyster beds nearly blocked the mouth of the Hudson River, and when the early-twentieth-century American adventure writer Zane Grey marveled at the enormous swordfish, tuna, wahoo, and grouper he found in the Gulf of California. Today, the human appetite has nearly wiped those populations out. It's no wonder that stocks of large predator fish are rapidly dwindling when one considers the fact that one bluefin tuna can go for hundreds of thousands of dollars at market in Japan. High prices -- in January 2013, a 489-pound Pacific bluefin tuna sold for $1.7 million at auction in Tokyo -- make it profitable to employ airplanes and helicopters to scan the ocean for the fish that remain; against such technologies, marine animals don't stand a chance. Nor are big fish the only ones that are threatened. In area after area, once the long-lived predatory species, such as tuna and swordfish, disappear, fishing fleets move on to smaller, plankton-eating fish, such as sardines, anchovy, and herring. The overexploitation of smaller fish deprives the larger wild fish that remain of their food; aquatic mammals and sea birds, such as ospreys and eagles, also go hungry. Marine scientists refer to this sequential process as fishing down the food chain. The problem is not just that we eat too much seafood; it's also how we catch it. Modern industrial fishing fleets drag lines with thousands of hooks miles behind a vessel, and industrial trawlers on the high seas drop nets thousands of feet below the sea's surface. In the process, many untargeted species, including sea turtles, dolphins, whales, and large sea birds (such as albatross) get accidentally captured or entangled. Millions of tons of unwanted sea life is killed or injured in commercial fishing operations each year; indeed, as much as a third of what fishermen pull out of the waters was never meant to be harvested. Some of the most destructive fisheries discard 80 to 90 percent of what they bring in. In the Gulf of Mexico, for example, for every pound of shrimp caught by a trawler, over three pounds of marine life is thrown away. As the oceans decline and the demand for their products rises, marine and freshwater aquaculture may look like a tempting solution. After all, since we raise livestock on land for food, why not farm fish at sea? Fish farming is growing faster than any other form of food production, and today, the majority of commercially sold fish in the world and half of U.S. seafood imports come from aquaculture. Done right, fish farming can be environmentally acceptable. But the impact of aquaculture varies widely depending on the species raised, methods used, and location, and several factors make healthy and sustainable production difficult. Many farmed fish rely heavily on processed wild fish for food, which eliminates the fish-conservation benefits of aquaculture. Farmed fish can also escape into rivers and oceans and endanger wild populations by transmitting diseases or parasites or by competing with native species for feeding and spawning grounds. Open-net pens also pollute, sending fish waste, pesticides, antibiotics, uneaten food, diseases, and parasites flowing directly into the surrounding waters. DESTROYING THE EARTH'S FINAL FRONTIER Yet another factor driving the decline of the oceans is the destruction of the habitats that have allowed spectacular marine life to thrive for millennia. Residential and commercial development have laid waste to once-wild coastal areas. In particular, humans are eliminating coastal marshes, which serve as feeding grounds and nurseries for fish and other wildlife, filter out pollutants, and fortify coasts against storms and erosion. Hidden from view but no less worrying is the wholesale destruction of deep-ocean habitats. For fishermen seeking ever more elusive prey, the depths of the seas have become the earth's final frontier. There, submerged mountain chains called seamounts -- numbering in the tens of thousands and mostly uncharted -- have proved especially desirable targets. Some rise from the sea floor to heights approaching that of Mount Rainier, in Washington State. The steep slopes, ridges, and tops of seamounts in the South Pacific and elsewhere are home to a rich variety of marine life, including large pools of undiscovered species. Today, fishing vessels drag huge nets outfitted with steel plates and heavy rollers across the sea floor and over underwater mountains, more than a mile deep, destroying everything in their path. As industrial trawlers bulldoze their way along, the surfaces of seamounts are reduced to sand, bare rock, and rubble. Deep cold-water corals, some older than the California redwoods, are being obliterated. In the process, an unknown number of species from these unique islands of biological diversity -- which might harbor new medicines or other important information -- are being driven extinct before humans even get a chance to study them. Relatively new problems present additional challenges. Invasive species, such as lionfish, zebra mussels, and Pacific jellyfish, are disrupting coastal ecosystems and in some cases have caused the collapse of entire fisheries. Noise from sonar used by military systems and other sources can have devastating effects on whales, dolphins, and other marine life. Large vessels speeding through busy shipping lanes are also killing whales. Finally, melting Arctic ice creates new environmental hazards, as wildlife habitats disappear, mining becomes easier, and shipping routes expand. Many common fishing practices hurt the fragile ecosystems by choosing profit over the ecosystemsOcean Focus 2011 (Ocean Focus, organization advocating for the protection of marine life, “Harmful Fishing Practices”, 2011, http://oceanfocus.org/focus-areas/fisheries-management/harmfull-fishing-practices/, SM) Bottom trawling used to have a more limited effect, as trawlers were unable to operate in areas where their nets would snag and tear, such as reefs. However, since the 1980s, trawl nets have been fitted with rubber tyres or rollers, which allow them to move over rough surfaces and therefore exploit more environments. The two boards on either side of the mouth of some nets, known as otter boards, can be extremely heavy and plough deep furrows through the sea bed. Causing even more damage than otter boards is a method known as a beam trawl, that has chains disturbing sediment twice as deep. The largest trawl nets can have a mouth over 100m wide and can be 0.5km long, something which has developed as boats have become powerful enough to pull them. Ghost fishing is the term for the damage caused by lost fishing gear, which is often made of non-biodegradable synthetic fibres. Although not actually a fishing practice in itself, it’s the end-result of a variety of different practices. The damage caused by ghost fishing is difficult to measure, but thousands of kilometres of nets are lost every year; often catching seabirds if they remain near the surface. Nets can become snagged on the bottom and fill up with catch, or drift through the water, still trapping marine life. Ghost fishing only stops if the net is destroyed by storms and swells, or it washed ashore. Pots (box shaped traps filled with bait usually used to attract crabs or lobster), are often made of more durable materials than nets and if lost, can continue to operate almost indefinitely as scavengers are attracted to them; continually providing fresh bait in a cycle of consumption and decay.¶ Hand collection by scuba divers should be the most selective method to a target species, particularly if it takes place on a small scale. But in recent years, divers have been causing significant damage to vulnerable ecosystems by using two techniques: dynamite and cyanide. Fishermen use mining explosives and armaments to create an explosion in deep water, known as blast-fishing. The shockwave created kills most fish in a 50m radius or more, most of which are not even collected by the fishermen. The explosions cause irreversible damage to reefs, as they are reduced to rubble, resulting in a marked reduction in biodiversity. Blast-fishing is most prevalent in Southeast Asia.¶ Cyanide fishing has also grown markedly over the last 30 years, to satisfy the demand for live fish both for the aquarium trade and human consumption. This is also most common in Southeast Asia to meet the growing demand from Singapore, Hong Kong and more recently, mainland China. The cyanide only stuns the fish, so they can be removed and will recover, at least temporarily, if placed in clean water. Cyanide damages coral and for every fish caught using this method, a square metre of coral is destroyed. ¶ Many people cite the world demand for seafood and fish as the real culprit for destroying coral reefs, wetlands and ocean beds, but other environmentalist blame the methods and practices of the fishing industry. These practices have devastated the ocean floor eco-systems in many places so that marine and aquatic life can no longer be sustained.¶ ¶ Modifying and Changing Fishing Methods¶ In order to lessen the impact of commercial fishing and overfishing that reaches beyond the ocean floor and into entire aquatic eco-systems, a global conservation effort is needed. 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