» 
Arabic Bulgarian Chinese Croatian Czech Danish Dutch English Estonian Finnish French German Greek Hebrew Hindi Hungarian Icelandic Indonesian Italian Japanese Korean Latvian Lithuanian Malagasy Norwegian Persian Polish Portuguese Romanian Russian Serbian Slovak Slovenian Spanish Swedish Thai Turkish Vietnamese
Arabic Bulgarian Chinese Croatian Czech Danish Dutch English Estonian Finnish French German Greek Hebrew Hindi Hungarian Icelandic Indonesian Italian Japanese Korean Latvian Lithuanian Malagasy Norwegian Persian Polish Portuguese Romanian Russian Serbian Slovak Slovenian Spanish Swedish Thai Turkish Vietnamese

definition - Sustainable_fisheries

definition of Wikipedia

   Advertizing ▼

Wikipedia

Sustainable fisheries

From Wikipedia, the free encyclopedia

Jump to: navigation, search
SeaWiFS map showing the levels of primary production in the world's oceans

Strategies and techniques for achieving sustainability in fisheries combine 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 conservation law and policy, setting up protected areas, restoring collapsed fisheries through skilful interventions, recognition of the real economics involved in harvesting marine ecosystems, educating stakeholders and the wider public, and developing independent certification programs for sustainable fisheries.

The concern about sustainability in fisheries is not so much that important fish species will be fished to extinction, but rather that heavy fishing pressures, such as overexploitation and growth or recruitment overfishing, will result in the loss of significant potential yield; that stock components will erode to the point where the stock structure loses diversity and resilience to environmental fluctuations; that ecosystems and their economic infrastructures will cycle between periods of rebuilding, losing productivity during each cycle; and that changes will occur in the trophic balance within ecosystems ("fishing down the web").[1]

Contents

Overview

This article is concerned, not so much with documenting the many unsustainable and destructive fishing practices, but with documenting the views of some fisheries scientists and marine conservationists about what is possible in the direction of sustainable fisheries. While fishery ecosystems, on the face of it, are just a subset of the wider marine environment, the fisheries scientists, Daniel Pauly and Dave Preikshot, comment:

Sustainable management of fisheries cannot be achieved without an acceptance that the long-term goals of fisheries management are the same as those of environmental conservation[2]

Traditional management of fisheries

Traditionally, fisheries management, and the science underpinning it, focused on the population dynamics of single commercial fish species, and ignored the wider ecosystem complexities associated with the species, as well as the underlying conservation issues.[2] Historically, fisheries stock assessment scientists usually worked in government laboratories and considered their work was in the service of the fishing industry. In this way, these scientists dismissed conservation issues and distanced themselves from the scientists and the science that raised the issues. This happened, even though many commercial fish stocks seriously deteriorated, and even though many governments were signaturies to binding agreements to conserve marine biodiversity.[2]

According to Daniel Pauly and Dave Preikshot, this traditional attitude towards conservation was based on two pathologies: the first pathology was "the narrow focus on target populations and the corresponding failure to account for ecosystem effects leading to declines of species abundance and diversity", and the second pathology was perceiving the fishing industry as "the sole legitimate user, in effect the owner, of marine living resources."[2]

Defining sustainability

The notion of sustainable development is sometimes regarded as an unattainable, even illogical notion because development inevitably depletes and degrades the environment.[3]

Ray Hilborn, of the University of Washington, distinguishes three ways of defining a sustainable fishery.

  • Long term constant yield is the idea that, when undisturbed, nature establishes a steady state that changes little over time. If fishing is done properly, at about the level of maximum sustainable yield, then nature will also adjust and settle down to a new steady state, with the harvest occurring sustainably in a stable and predictable way. However, this is a naive view. Such constancy is not an attribute of marine ecosystems, and this approach fails. It is entirely natural for stock abundance to fluctuate, and the potential yield of fish stocks changes with naturally occurring short and long term variations.[1]
  • Preserving intergenerational equity acknowledges that natural fluctuations occur, and regards as unsustainable practices which would result in a deterioration of the genetic structure, or habitat loss, or depletion of stock levels to the point where it requires several generations for rebuilding. Providing the stock can be rebuild within one generation, overfishing may be economically foolish, but it is not unsustainable. This is currently a widely accepted definition.[1]
  • Maintaining a biological, social and economic system is a perspective which considers the health of the human ecosystem as well as the marine ecosystem. A mixed-species fishery which rotates its fishing effort can deplete individual stocks and still be sustainable so long as the ecosystem retains its intrinsic integrity. Such a definition might consider as sustainable fishing practices that lead to the reduction and possible extinction of some members of the ecosystem.[1]

Protecting biodiversity

Reconciling fisheries with conservation

At the Fourth World Fisheries Congress in 2004, Daniel Pauly asked, "How can fisheries science and conservation biology achieve a reconciliation?", and answered his own question, "By accepting each other’s essentials: that fishing should remain a viable occupation; and that aquatic ecosystems and their biodiversity are allowed to persist."[4]

Social sustainability

The fisheries and aquaculture sectors are, directly or indirectly, a source of livelihood for over 500 million people, mostly in developing countries.[5] While it is important to protect biodiversity, people also need seafood to ensure food security.[6]

Taking account of social sustainability can conflict with the need to protect biodiversity. A fishery is socially sustainable if the fishery ecosystem maintains the ability to deliver products the social system can use. From the social point of view, major species shifts within the ecosystem could be acceptable as long as the new species can be properly utilised.[1] There is nothing new in this; humans have been operating such regimes for thousands of years, transforming many ecosystem, species of which have been depleted or driven to extinction.[7]

According to Hilborn, the "loss of some species, and indeed transformation of the ecosystem is not incompatible with sustainable harvests."[1] For example, in recent years, barndoor skates have been caught as bycatch in the western Atlantic. Their numbers have severely declined and they will probably go extinct if these catch rates continue.[8] Even if the barndoor skate goes extinct, and even if there is a consequent change in the ecosystem, there could still be long term sustainable fishing of the commercially important species.[1]

To a great extent, sustainability is like good art, it is hard to describe but we know it when we see it.Ray Hilborn[1]

Overfishing

There is a misconception that overfishing is always unsustainable. According to Hilborn, overfishing can be "a misallocation of societies resources", but it does not necessarily threaten conservation or sustainability.[1]"

Overfishing is traditionally defined as fishing so hard that the yield from a stock is less that it would be if the fishing pressure were reduced.[1] For example, Pacific salmon are usually managed by trying to determine how many spawning salmon are needed each generation to produce the maximum harvestable surplus. The number allowed to spawn is called the escapement. The optimum escapement is the escapement needed to produce the maximum harvestable surplus. For optimal management, the number of spawners each year is the optimum escapement. If the fishery was managed so the escapement was only half the optimum, then overfishing will occur, because the harvest would be smaller than it need be. But this is still sustainable fishing, which could continue indefinitely at its reduced stock numbers and yield. There is a wide range of escapement sizes that present no threat that the stock might collapse or that the stock structure might erode.[1]

On the other hand, overfishing can be a predecessor to severe stock depletion and fishery collapse.[9] Hilborn points out that this syndrome, of continuing to exert fishing pressure while biological production decreases, leading eventually to stock collapse and failure of the fishery, is largely "the product of institutional failure."[1]

A Hubbert linearization (Hubbert curve) has been applied to the whaling industry, as well as charting the transparently dependent price of caviar on sturgeon depletion. [10] Another example is the cod of the North Sea. The comparison of the cases of fisheries and of mineral extraction tells us that the human pressure on the environment is causing a wide range of resources to go through a depletion cycle which follows a Hubbert curve.[11]

Incidental catch

[2]

Shifting environmental baselines

Habitat modification

     The global continental shelf, highlighted in cyan

Ecosystem change due to human interference.

Nearly all the world’s continental shelves, and large areas of continental slopes, underwater ridges, and seamounts, have had heavy bottom trawls and dredges repeatedly dragged over their surfaces. For fifty years, governments and organizations, such as the Asian Development Bank, have encouraged fishing industries to develop trawler fleets. Repeated bottom trawling and dredging literally flattens diversity in the benthic habitat, and the associated communities are radically changed.[12]

Changing the ecosystem balance

Fishing down the marine web.

Since 1950, 90 percent of 25 species of big predator fish have gone.

Climate change

Fishing with a lift net in Bangladesh. Coastal fishing communities in Bangladesh are vulnerable to flooding from sea-level rises.[13]

Rising ocean temperatures[14] and ocean acidification[15] are radically altering aquatic ecosystems. Climate change is modifying fish distribution[16] and the productivity of marine and freshwater species. This has impacts on the sustainability of fisheries and aquaculture, on the livelihoods of the communities that depend on fisheries, and on the ability of the oceans to capture and store carbon (biological pump). The effect of sea level rise means that coastal fishing communities are in the front line of climate change, while changing rainfall patterns and water use impact on inland (freshwater) fisheries and aquaculture.

Ocean pollution

Island with fringing reef in the Maldives. Coral reefs are dying around the world.[17]

A recent survey of global ocean health concluded that all parts of the ocean have been impacted by the human species, and that 41 percent of the oceans has been fouled with human polluted runoff, overfishing, and other abuses.[18] Pollution is a problem which is not easy to fix, because the sources of pollution are so dispersed, and are built into the economic systems we depend on.

  • The United Nations Environment Programme (UNEP) released a report mapping the myriad impacts of stressors such as climate change, pollution, exotic species, and over-exploitation of resources on the world ocean. The report shows at least 75 percent of the world's key fishing grounds may be affected.
  • Nellemann, C., Hain, S., and Alder, J. (Eds). February 2008. In Dead Water: Merging of climate change with pollution, over-harvest, and infestations in the world’s fishing grounds. United Nations Environment Programme, GRID-Arendal, Norway. Available at http://www.unep.org/pdf/InDeadWater_LR.pdf Off-site Link

Diseases and toxins

Is eating fish necessarily better than eating other food? Large predator fish contain significant amounts of mercury, a neurotoxin which can affect foetal development, memory, the mental ability to focus, and give tremors.

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 means to implement the rules, which are put in place by a system of monitoring control and surveillance.

Global Fisheries Management
Ideas and rules

The American economist Paul Romer believes sustainable growth is possible providing the right ideas (technology) are combined with the right rules. He believes that rather than hectoring people about our predicament, we should think our way out of it by finding the right creative ideas, and coupling them with appropriate rules governing the way the ideas are implemented. There has been no lack of innovative ideas about how to harvest fish. He characterises the failures of fisheries management as primarily failures to apply appropriate rules.[19][20]

Fishing Subsidies

Government subsidies operate in many of the world fisheries. Subsidisies on the the costs of operating fishing vessels allow European and Asian fishing fleets to fish in distant waters, such as West African waters. Many fisheries experts believe fishing subsidies should be eliminated and that fishing incentives should be restructured globally to help struggling fisheries recover.[21]

Economics

Another focus of conservationists is on curtailing human activities that are detrimental to either marine ecosystems or species through policy, techniques such as fishing quotas, like those set up by the Northwest Atlantic Fisheries Organization, or laws such as those listed below. Recognizing the economics involved in human use of marine ecosystems is key, as is education of the public about conservation issues.

Sustainable Fisheries Certification

A promising direction is the independent certification programs for sustainable fisheries conducted by organisations such as the Marine Stewardship Council and Friend of the Sea. These programs work at raising consumer awareness and insight into the nature of their seafood purchases

Coastal waters
International waters

Need for adequate data

One of the major impediments to the rational control of marine resources is a deficiency of data. According to fisheries scientist Milo Adkison (2007), the primary limitation in fisheries management decisions is the absence of quality data. Fisheries management decisions are often based on population models, but the models need quality data to be effective. Scientists and fishery managers would be better served with simpler modelling analyses and improved data.[22]

Marine protected areas

Strategies and techniques for marine conservation tend to combine theoretical disciplines, such as population biology, with practical conservation strategies, such as setting up protected areas, as with marine protected areas (MPAs) or Voluntary Marine Conservation Areas.

Marine life is not evenly distributed in the oceans. Most of the really valuable ecosystems inhabit relatively shallow coastal waters, above or near the continental shelf, where the sunlit waters are often nutrient rich from land runoff or upwellings at the continental edge, allowing photosynthesis to take place. In the 1970s, for reasons more to do with drilling for oil than with fishing, the U.S. extended their national jurisdiction, which was out to 12 miles from the coast, to 200 miles. This made huge areas of continental shelf part of their national territory. Other nations immediately did the same, extending national controls to what became known as the exclusive economic zone (EEZ). This move has had many implications for fisheries conservation, since it means that large areas of the world's most productive maritime ecosystems are now under national jurisdictions, opening possibilities for protecting these ecosystems by passing appropriate national laws.

Daniel Pauly characterises marine protected areas as "a conservation tool of revolutionary importance that is being incorporated into the fisheries mainstream."[2] The Pew Charitable Trusts have funded various initiatives aimed at encouraging the development of MPAs and other ocean conservation measures.[23]

Ecosystem based fisheries

According to marine ecologist Chris Frid, the fishing industry has been keen to identify pollution and global warming as the causes of unprecedented low fish levels in recent years. But it is clear that overfishing has also altered the way the ecosystem works. "Everybody would like to see the rebuilding of fish stocks and this can only be achieved if we understand all of the influences, human and natural, on fish dynamics.” Frid adds: “Fish communities can be altered in a number of ways, for example they can decrease if particular sized individuals of a species are targeted, as this affects predator and prey dynamics. Fishing, however, is not the sole perpetrator of changes to marine life - pollution is another example [...] No one factor operates in isolation and components of the ecosystem respond differently to each individual factor."[24]

The traditional approach to fisheries science and management has been to focus on a single species. This can be contrasted with the ecosystem-based approach. Ecosystem-based fishery concepts have existed for some years and have been implemented in some regions. In a recent (2007) effort to "stimulate much needed discussion" and "clarify the essential components" of ecosystem-based fisheries science, a group of scientists have offered the following ten commandments for ecosystem-based fisheries scientists[25]

  • Keep a perspective that is holistic, risk-adverse and adaptive.
  • Maintain an “old growth” structure in fish populations, since big, old and fat female fish have been shown to be the best spawners, but are also susceptible to overfishing.
  • Characterize and maintain the natural spatial structure of fish stocks, so that management boundaries match natural boundaries in the sea.
  • Monitor and maintain seafloor habitats to make sure fish have food and shelter.
  • Maintain resilient ecosystems that are able to withstand occasional shocks.
  • Identify and maintain critical food-web connections, including predators and forage species.
  • Adapt to ecosystem changes through time, both short-term and on longer cycles of decades or centuries, including global climate change.
  • Account for evolutionary changes caused by fishing, which tends to remove large, older fish.
  • Include the actions of humans and their social and economic systems in all ecological equations.

Fish farming

To what extent can farmed fish be part of the answer? Farmed salmon, eat three pounds of wild fish to produce one pound of salmon.

Laws and treaties

International laws and treaties related to marine conservation include the 1966 Convention on Fishing and Conservation of Living Resources of the High Seas. United States laws related to marine conservation include the 1972 Marine Mammal Protection Act, as well as the 1972 Marine Protection, Research and Sanctuaries Act which established the National Marine Sanctuaries program. Magnuson-Stevens Fishery Conservation and Management Act.

Awareness campaigns

There are organizations throughout the world that focus on promoting strategies for sustainable fishing, educating the public and stakeholders, and lobbying for conservation law and policy. Examples of these organizations are the Marine Conservation Biology Institute (United States),Blue Frontier Campaign (United States), Frontier (the Society for Environmental Exploration) (United Kingdom), Marine Conservation Society (United Kingdom), Australian Marine Conservation Society, International Council for the Exploration of the Sea (ICES), Langkawi Declaration, Oceana, PROFISH, and the Sea Around Us Project.

International Collective in Support of Fishworkers, World Forum of Fish Harvesters and Fish Workers, Frozen at Sea Fillets Association, CEDO

The United Nations Millennium Development Goals include, as goal #7: target 2, the intention to "reduce biodiversity loss, achieving, by 2010, a significant reduction in the rate of loss", including improving fisheries management to reduce depletion of fish stocks.[26][27]

Some organisation offer sustainable or good practice certification to fishing industry players, such as the Marine Stewardship Council and Friend of the Sea.

There are also organisations which offer advice to those members of the public who want to choose the seafood they eat with an eye to sustainability. According to the marine conservation biologist Callum Roberts, there are four things to look for when choosing seafood:[28]

  • Is the species in trouble in the wild where the animals were caught?
  • Does fishing for the species damage ocean habitats?
  • Is there a large amount of unwanted bycatch taken with the target species?
  • Does the fishery have a problem with discards – generally undersized animals caught and thrown away because their market value is low?

The following organisations have links where wallet-sized cards, listing best choices and species to avoid, can be downloaded:

Postscript

In 1883, Thomas Huxley gave the inaugural address at the International Fisheries Exhibition in London. There he asserted that overfishing or "permanent exhaustion" was scientifically impossible, and stated his belief that probably "all the great sea fisheries are inexhaustible".[29] In reality, marine fisheries were already collapsing. The United States Fish Commission was established 12 years earlier for the purpose of finding why fisheries in New England were declining. And at the time of Huxley's address, the Atlantic halibut fishery had already collapsed[30] (and has never recovered).

In the end, we will conserve only what we love;
we will love only what we understand;
and we will understand only what we are taught.
– Senegalese conservationalist Baba Dioum[31]

See also

Notes

  1. ^ a b c d e f g h i j k l Hilborn, Ray (2005) "Are Sustainable Fisheries Achievable?" Chapter 15, pp. 247–259, in Norse and Crowder (2005).
  2. ^ a b c d e f Preikshot, Dave and Pauly, Daniel (2005) "Global Fisheries and Marine Conservation: Is Coexistence Possible?" Chapter 11, pp. 185–197, in Norse and Crowder (2005).
  3. ^ Redclift, M. (2005). "Sustainable Development (1987–2005): an Oxymoron Comes of Age." Sustainable Development 13(4): 212–227.
  4. ^ Pauly, Daniel (2004) Reconciling Fisheries with Conservation: the Challenge of Managing Aquatic Ecosystems Fourth World Fisheries Congress, Vancouver, 2004.
  5. ^ Fisheries and Aquaculture in our Changing Climate Policy brief of the FAO for the UNFCCC COP-15 in Copenhagen, December 2009.
  6. ^ The Missing Element, Samudra Report of the ICSF, Issue 43, March 2006.
  7. ^ Johannes R (1981) Words of the lagoon: Fishing and Marine Lore in the Palau District of Micronesia, University of California Press. ISBN 0520039297
  8. ^ Casey JM and Myers RA (1998) "Near extinction of a large, widely distributed fish" Science, 280:690–692.
  9. '^ Ludwig D, Hilborn R and Walter C (1993) "Uncertainty, resource exploitation and conservation: Lessons from history", Science, 230:17–26.
  10. ^ http://www.aspoitalia.net/index.php?option=com_content&task=view&id=34&Itemid=39
  11. ^ http://www.hubbertpeak.com/laherrere/multihub.htm
  12. ^ (Watling, Les (2005) "The global destruction of bottom habitats by mobile fishing gear" Chapter 12, pp. 198–210, in Norse and Crowder (2005).
  13. ^ Sarwar G.M. (2005) "Impacts of Sea Level Rise on the Coastal Zone of Bangladesh" Masters thesis. Lund University.
  14. ^ Observations: Oceanic Climate Change and Sea Level In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. (15MB).
  15. ^ Doney, S. C. (2006) "The Dangers of Ocean Acidification" Scientific American, March 2006.
  16. ^ Cheung, W.W.L., et al. (2009) "Redistribution of Fish Catch by Climate Change. A Summary of a New Scientific Analysis" Pew Ocean Science Series. Oct 2009.
  17. ^ Coral reefs around the world Guardian.co.uk, 2 September 2009.
  18. ^ Benjamin S. Halpern, Shaun Walbridge, Kimberly A. Selkoe, Carrie V. Kappel, Fiorenza Micheli, Caterina D'Agrosa et al. 15 February 2008. "A Global Map of Human Impact on Marine Ecosystems." Science, 319(5865):948–952.
  19. ^ Fish Proverb v2.0 (Bringing in Rules) Paul Romer, 29 July 2009.
  20. ^ Running notes from session 7 Paul Romer at TEDGlobal 2009.
  21. ^ Sumaila, U.R. and Pauly, D. (2007). "All fishing nations must unite to end subsidies." Nature, 450: 945.
  22. ^ University of Alaska Fairbanks (2007) Adkison advocates increased fisheries data gathering
  23. ^ Pew, SeaWeb shrug off oil to target fishing. Retrieved 11 October 2009.
  24. ^ University of Liverpool (2006). "Marine Ecologists To Help Rebuild Decreasing Fish Stocks" ScienceDaily.
  25. ^ Francis RC, Hixon MA, Clarke ME, Murawski SA, and Ralston S (2007) Ten commandments for ecosystem-based fisheries scientists Proceedings of Coastal Zone 07, Portland, Oregon. Download
  26. ^ Millennium Development Report 2008: Goal 7: Ensure environmental sustainability United Nations.
  27. ^ Millennium Development Report 2008 United Nations.
  28. ^ Advice for Seafood Lovers Callum Roberts. Retrieved 20 September 2009.
  29. ^ Huxley, Thomas (1883)Inaugural Address Fisheries Exhibition, London.
  30. ^ Goode GB and Collins JW (1887) "The fresh-halibut fishery". In: The fisheries and fishery industry of the United States. Section V. History and methods of the fisheries, Vol. I, Part I. Government Printing Office, Washington, DC. p. 3–89.
  31. ^ Norse & Crowder 2005, Page xix

References

External links


 

All translations of Sustainable_fisheries


sensagent's content

  • definitions
  • synonyms
  • antonyms
  • encyclopedia

Dictionary and translator for handheld

⇨ New : sensagent is now available on your handheld

   Advertising ▼

sensagent's office

Shortkey or widget. Free.

Windows Shortkey: sensagent. Free.

Vista Widget : sensagent. Free.

Webmaster Solution

Alexandria

A windows (pop-into) of information (full-content of Sensagent) triggered by double-clicking any word on your webpage. Give contextual explanation and translation from your sites !

Try here  or   get the code

SensagentBox

With a SensagentBox, visitors to your site can access reliable information on over 5 million pages provided by Sensagent.com. Choose the design that fits your site.

Business solution

Improve your site content

Add new content to your site from Sensagent by XML.

Crawl products or adds

Get XML access to reach the best products.

Index images and define metadata

Get XML access to fix the meaning of your metadata.


Please, email us to describe your idea.

WordGame

The English word games are:
○   Anagrams
○   Wildcard, crossword
○   Lettris
○   Boggle.

Lettris

Lettris is a curious tetris-clone game where all the bricks have the same square shape but different content. Each square carries a letter. To make squares disappear and save space for other squares you have to assemble English words (left, right, up, down) from the falling squares.

boggle

Boggle gives you 3 minutes to find as many words (3 letters or more) as you can in a grid of 16 letters. You can also try the grid of 16 letters. Letters must be adjacent and longer words score better. See if you can get into the grid Hall of Fame !

English dictionary
Main references

Most English definitions are provided by WordNet .
English thesaurus is mainly derived from The Integral Dictionary (TID).
English Encyclopedia is licensed by Wikipedia (GNU).

Copyrights

The wordgames anagrams, crossword, Lettris and Boggle are provided by Memodata.
The web service Alexandria is granted from Memodata for the Ebay search.
The SensagentBox are offered by sensAgent.

Translation

Change the target language to find translations.
Tips: browse the semantic fields (see From ideas to words) in two languages to learn more.

last searches on the dictionary :

5343 online visitors

computed in 0.078s

   Advertising ▼

I would like to report:
section :
a spelling or a grammatical mistake
an offensive content(racist, pornographic, injurious, etc.)
a copyright violation
an error
a missing statement
other
please precise:

Advertize

Partnership

Company informations

My account

login

registration

   Advertising ▼