The environmental impact of fishing can be divided into issues that involve the availability of fish to be caught, such as overfishing

Overfishing

Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....

, sustainable fisheries

Sustainable fisheries

Sustainability in fisheries combines theoretical disciplines, such as the population dynamics of fisheries, with practical strategies, such as avoiding overfishing through techniques such as individual fishing quotas, curtailing destructive and illegal fishing practices by lobbying for appropriate...

, and fisheries management

Fisheries management

Fisheries management draws on fisheries science in order to find ways to protect fishery resources so sustainable exploitation is possible. Modern fisheries management is often referred to as a governmental system of appropriate management rules based on defined objectives and a mix of management...

; and issues that involve the impact of fishing on other elements of the environment, such as by-catch

By-catch

The term “bycatch” is usually used for fish caught unintentionally in a fishery while intending to catch other fish. It may however also indicate untargeted catch in other forms of animal harvesting or collecting...

.

These conservation issues are part of marine conservation

Marine conservation

Marine conservation, also known as marine resources conservation, is the protection and preservation of ecosystems in oceans and seas. Marine conservation focuses on limiting human-caused damage to marine ecosystems, and on restoring damaged marine ecosystems...

, and are addressed in fisheries science

Fisheries science

Fisheries science is the academic discipline of managing and understanding fisheries. It is a multidisciplinary science, which draws on the disciplines of oceanography, marine biology, marine conservation, ecology, population dynamics, economics and management to attempt to provide an integrated...

 programs. There is a growing gap between how many fish are available to be caught and humanity’s desire to catch them, a problem that gets worse as the world population

World population

The world population is the total number of living humans on the planet Earth. As of today, it is estimated to be  billion by the United States Census Bureau...

 grows.

Similar to other environmental issues, there can be conflict between the fishermen who depend on fishing for their livelihoods and fishery scientists who realise that if future fish populations are to be sustainable

Sustainability

Sustainability is the capacity to endure. For humans, sustainability is the long-term maintenance of well being, which has environmental, economic, and social dimensions, and encompasses the concept of union, an interdependent relationship and mutual responsible position with all living and non...

 then some fisheries must reduce or even close.

The journal Science

Science (journal)

Science is the academic journal of the American Association for the Advancement of Science and is one of the world's top scientific journals....

published a four-year study in November 2006, which predicted that, at prevailing trends, the world would run out of wild-caught seafood

Seafood

Seafood is any form of marine life regarded as food by humans. Seafoods include fish, molluscs , crustaceans , echinoderms . Edible sea plants, such as some seaweeds and microalgae, are also seafood, and are widely eaten around the world, especially in Asia...

 in 2048. The scientists stated that the decline was a result of overfishing

Overfishing

Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....

, pollution

Pollution

Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...

 and other environmental factors that were reducing the population of fisheries at the same time as their ecosystems were being degraded. Yet again the analysis has met criticism as being fundamentally flawed, and many fishery management officials, industry representatives and scientists challenge the findings, although the debate continues. Many countries, such as Tonga

Tonga

Tonga, officially the Kingdom of Tonga , is a state and an archipelago in the South Pacific Ocean, comprising 176 islands scattered over of ocean in the South Pacific...

, the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 and New Zealand

New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

, and international management bodies have taken steps to appropriately manage marine resources.

Effects on habitat

Some fishing techniques also may cause habitat destruction. Dynamite fishing and cyanide fishing

Cyanide fishing

Cyanide fishing is a method of collecting live fish mainly for use in aquariums, which involves spraying a sodium cyanide mixture into the desired fish's habitat in order to stun the fish...

, which are illegal in many places, harm surrounding habitat. Bottom trawling

Bottom trawling

Bottom trawling is trawling along the sea floor. It is also often referred to as "dragging".The scientific community divides bottom trawling into benthic trawling and demersal trawling...

, the practice of pulling a fishing net along the sea bottom behind trawlers, removes around 5 to 25% of an area's seabed life on a single run. A 2005 report of the UN Millennium Project, commissioned by UN Secretary-General Kofi Annan

Kofi Annan

Kofi Atta Annan is a Ghanaian diplomat who served as the seventh Secretary-General of the UN from 1 January 1997 to 31 December 2006...

, recommended the elimination of bottom trawling on the high seas by 2006 to protect seamounts and other ecologically sensitive habitats.

In mid October 2006, U.S. President Bush joined other world leaders calling for a moratorium on deep-sea trawling

Trawling

Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net that is used for trawling is called a trawl....

, a practice shown to often have harmful effects on sea habitat and, hence, on fish populations.

Overfishing

Overfishing

Overfishing

Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....

 has also been widely reported due to increases in the volume of fishing hauls to feed a quickly growing number of consumers. This has led to the breakdown of some sea ecosystems and several fishing industries whose catch has been greatly diminished. The extinction of many species has also been reported. According to an FAO

Fão

Fão is a town in Esposende Municipality in Portugal....

 estimate, over 70% of the world’s fish species are either fully exploited or depleted. According to Nitin Desai, Secretary General of the 2002 World Summit on Sustainable Development, "Overfishing cannot continue, the depletion of fisheries poses a major threat to the food supply of millions of people."

The cover story of the May 15, 2003 issue of the science journal Nature

Nature (journal)

Nature, first published on 4 November 1869, is ranked the world's most cited interdisciplinary scientific journal by the Science Edition of the 2010 Journal Citation Reports...

 – with Dr. Ransom A. Myers

Ransom A. Myers

Dr. Ransom Aldrich "Ram" Myers, Jr. was a world-renowned marine biologist and conservationist.He was the son of cotton planter, Ransom Aldrich Myers, Sr. and Fay A. Mitchell Myers...

, an internationally prominent fisheries biologist (Dalhousie University, Halifax, Canada) as the lead author – was devoted to a summary of the scientific information. The story asserted that, as compared with 1950 levels, only a remnant (in some instances, as little as 10%) of all large ocean-fish stocks are left in the seas. These large ocean fish are the species at the top of the food chains (e.g., tuna, cod, among others). However, this article was subsequently criticized as being fundamentally flawed, although much debate still exists (Walters 2003; Hampton et al. 2005; Maunder et al. 2006; Polacheck 2006;Sibert et al. 2006) and the majority of fisheries scientists now consider the results irrelevant with respect to large pelagics (the open seas).

Ecological disruption

Fishing may disrupt food web

Food web

A food web depicts feeding connections in an ecological community. Ecologists can broadly lump all life forms into one of two categories called trophic levels: 1) the autotrophs, and 2) the heterotrophs...

s by targeting specific, in-demand species. There might be too much fishing of prey species such as sardine

Sardine

Sardines, or pilchards, are several types of small, oily fish related to herrings, family Clupeidae. Sardines are named after the Mediterranean island of Sardinia, around which they were once abundant....

s and anchovies, thus reducing the food supply for the predators. It may also cause the increase of prey species when the target fishes are predator species such as salmon

Salmon

Salmon is the common name for several species of fish in the family Salmonidae. Several other fish in the same family are called trout; the difference is often said to be that salmon migrate and trout are resident, but this distinction does not strictly hold true...

 and tuna

Tuna

Tuna is a salt water fish from the family Scombridae, mostly in the genus Thunnus. Tuna are fast swimmers, and some species are capable of speeds of . Unlike most fish, which have white flesh, the muscle tissue of tuna ranges from pink to dark red. The red coloration derives from myoglobin, an...

. Fisheries can reduce fish stocks that cetaceans rely on for food.

By-catch

By-catch is the portion of the catch that is not the target species. These are either kept to be sold or discarded. In some instances the discarded portion is known as discards

Discards

Discards are the portion of a catch of fish which is not retained on board during commercial fishing operations and is returned, often dead or dying, to the sea...

.

Possible remedies

Many governments and intergovernmental bodies have implemented fisheries management

Fisheries management

Fisheries management draws on fisheries science in order to find ways to protect fishery resources so sustainable exploitation is possible. Modern fisheries management is often referred to as a governmental system of appropriate management rules based on defined objectives and a mix of management...

 policies designed to curb the environmental impact of fishing. Fishing conservation aims to control the human activities that may completely decrease a fish stock or washout an entire aquatic environment. These laws include the quotas on the total catch of particular species in a fishery, effort quotas (e.g., number of days at sea), the limits on the number of vessels allowed in specific areas, and the imposition of seasonal restrictions on fishing.

In 2008 a large scale study of fisheries that used individual transferable quotas and ones that didn't provided strong evidence that individual transferable quotas can help to prevent collapses and restore fisheries that appear to be in decline.

Fish farming

Fish farming

Fish farming is the principal form of aquaculture, while other methods may fall under mariculture. Fish farming involves raising fish commercially in tanks or enclosures, usually for food. A facility that releases young fish into the wild for recreational fishing or to supplement a species'...

 has been proposed as a more sustainable alternative to traditional capture of wild fish. However, fish farming has been found to have negative impacts on nearby wild fish. Further, farming of predatory fish like salmon can rely on fish feed that is based on fish meal

Fish meal

Fish meal, or fishmeal, is a commercial product made from both whole fish and the bones and offal from processed fish. It is a brown powder or cake obtained by rendering pressing the cooked whole fish or fish trimmings to remove most of the fish oil and water, and then ground...

 and oil

Fish oil

Fish oil is oil derived from the tissues of oily fish. Fish oils contain the omega-3 fatty acids eicosapentaenoic acid , and docosahexaenoic acid , precursors of certain eicosanoids that are known to reduce inflammation throughout the body, and are thought to have many health benefits.Fish do not...

 from wild fish

Forage fish

Forage fish, also called prey fish or bait fish, are small fish which are preyed on by larger predators for food. Predators include other larger fish, seabirds and marine mammals. Typical ocean forage fish feed near the base of the food chain on plankton, often by filter feeding...

.

The environmental impact of recreational fishing may be alleviated to some extent by catch and release

Catch and release

Catch and release is a practice within recreational fishing intended as a technique of conservation. After capture, the fish are unhooked and returned to the water before experiencing serious exhaustion or injury...

 fishing.

See also

• Population dynamics of fisheries
  Population dynamics of fisheries
  A fishery is an area with an associated fish or aquatic population which is harvested for its commercial or recreational value. Fisheries can be wild or farmed. Population dynamics describes the ways in which a given population grows and shrinks over time, as controlled by birth, death, and...
  
  
• Environmental effects of meat production
  Environmental effects of meat production
  The environmental impact of meat production includes pollution and the use of resources such as fossil fuels, water, and land. According to a 2006 report by the Livestock, Environment And Development Initiative, the livestock industry is one of the largest contributors to environmental degradation...
  
  
• The End of the Line: How Overfishing Is Changing the World and What We Eat
  The End of the Line: How Overfishing Is Changing the World and What We Eat
  The End of The Line: How Overfishing Is Changing the World And What We Eat is a book by journalist Charles Clover about overfishing. Clover, an environment editor of the Daily Telegraph , describes how modern fishing is destroying ocean ecosystems. He concludes that current worldwide fish...
  
  (book)
• One Fish, Two Fish, Crawfish, Bluefish
  One Fish, Two Fish, Crawfish, Bluefish
  One Fish, Two Fish, Crawfish, Bluefish: The Smithsonian Sustainable Seafood Cookbook is a collection of seafood recipes specifically chosen for their environmental sustainability. It was written by Carole C. Baldwin and Julie H...
  
  (book)
• Shark finning
  Shark finning
  Shark finning refers to the removal and retention of shark fins and the discarding of the rest of the fish. Shark finning takes place at sea so the fishers only have to transport the fins.Shark finning is widespread, and largely unmanaged and unmonitored...
  
  
• Sustainable food system
• Marine debris
  Marine debris
  Marine debris, also known as marine litter, is human created waste that has deliberately or accidentally become afloat in a lake, sea, ocean or waterway. Oceanic debris tends to accumulate at the centre of gyres and on coastlines, frequently washing aground, when it is known as beach litter or...
  
  

Further reading

• Castro, P. and M. Huber. (2003). Marine Biology. 4^th ed. Boston: McGraw Hill.
• Hampton, J., Sibert, J. R., Kleiber, P., Maunder, M. N., and Harley, S. J. 2005. Changes in abundance of large pelagic predators in the Pacific Ocean. Nature, 434: E2-E3.
• Maunder, M.N., Sibert, J.R. Fonteneau, A., Hampton, J., Kleiber, P., and Harley, S. 2006. Interpreting catch-per-unit-of-effort data to asses the status of individual stocks and communities. ICES Journal of Marine Science, 63: 1373-1385.
• Myers, Ransom and Boris Worm. (May 15, 2003). "Rapid worldwide depletion of predatory fish communities," Nature, Vol 423. London: Nature Publishing.
• Polacheck, T. 2006. "Tuna longline catch rates in the Indian Ocean: did industrial fishing result in a 90% rapid decline in the abundance of large predatory species?" Marine Policy, 30: 470-482.
• FAO Fisheries Department. (2002). The State of World Fisheries and Aquaculture. Rome: Food and Agriculture Organization of the United Nations.
• Sibert, et al. 2006. Biomass, Size, and Trophic Status of Top Predators in the Pacific Ocean Science 314: 1773
• Walters, C. J. 2003. Folly and fantasy in the analysis of spatial catch rate data. Canadian Journal of Fisheries and Aquatic Sciences, 60: 1433-1436.

External links

• Pelagic Fisheries Research Program
• International Collective in Support of Fishworkers website
• United Nations conference in criticism of deep-sea trawling
• Bush backs international deep-sea trawling moratorium
• Re-interpreting the Fisheries Crisis seminar by Prof. Ray Hilborn
• UK Database of commercially sold fish with stock status
• Database on stock status of US seafood
• Conservation Science Institute
• The facts about the Commercial Fishing Environment