Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fewer fish discarded after individual transferable quotas offered

29.03.2005


Contradicting previous assumptions, new fisheries research shows that allocating catch among vessels reduces the amount of fish discarded at sea.



The study in Canada’s British Columbia waters compared so-called individual transferable quotas with a previously used system of trip limits where vessels are only allowed to land a certain quantity of each species every two months.

The findings come at a time when individual transferable quotas are being considered for the west coast of the United States. "Economic models have assumed all along that individual transferable quotas increase discards," says Trevor Branch, who earned his doctorate in aquatic and fishery sciences at the University of Washington and is lead author of an article published online this week by the journal Marine Policy.


But discards did not increase – they declined for most species, report Trevor and co-authors Kate Rutherford, biologist with Fisheries and Oceans Canada in British Columbia, and Ray Hilborn, UW professor of aquatic and fishery sciences.

The study, "Replacing Trip Limits with Individual Transferable Quotas: Implications for Discarding," is the first to look at 35 species instead of only a handful, or even just a single species, before and after quotas were implemented.

With individual transferable quotas, the total allowable catch is divided among a limited number of boats with each quota holder receiving a specific proportion of the total catch. Quota holders then decide how and when to fish, and whether to buy additional quotas or lease or sell their quotas.

Such a system was implemented in British Columbia waters in 1997, after a one-year transition from individual trip limits and overall caps on the fleet. After a period of adjustment, rates have remained generally similar or even less than the 15 percent of fish discarded in 1996.

Discarding occurs when, for example, unmarketable fish are caught or where trip limits are imposed and once the maximum of a certain fish is caught, all the rest of that type of fish that is caught must be discarded.

Trip limits are used in U.S. waters to protect overfished stocks and they have proved effective, Branch says. "It’s just that perhaps the mortality could have been reduced just as much under individual transferable quotas and without discarding large amounts of marketable fish, an economic loss for fishers that is hard to estimate," he says.

Under British Columbia’s individual transferable quota system, for instance, skippers have had more flexibility to choose when, where and how to fish so fewer small, unmarketable fish were caught. Then too, skippers with more than their quota of a certain kind of fish could try to arrange to lease or buy another’s quota to cover the overage.

Other differences between the two systems include full mortality accounting in the British Columbia fishery – meaning any marketable fish that was discarded at sea was deducted from the amount the vessel was allowed to bring to shore – and the presence of observers on every boat. In the U.S. West Coast fishery, there is no deduction when marketable fish are discarded and in recent seasons monitors were on board 13 to 16 percent of the vessels.

In comparing the two fisheries, the researchers found British Columbia discard rates of 14 percent and 19 percent in two recent fishing seasons, compared with 43 percent and 31 percent for those same seasons in U.S. West Coast waters – the drop to 31 percent partly because new Groundfish Conservation Areas put some fishing grounds off limits, the scientists note. Which animals live once returned to the sea depends on the organism; for instance, species of rockfish all tend to die while lingcod and sablefish are among the fish with better survival rates.

"This research is interesting because it dramatically illustrates how discarding practices are influences by the regulation system," Branch says. "In the British Columbia fishery, individual transferable quotas combined with 100 percent observer coverage reduce discard rates of marketable fish to negligible amounts, whereas trip limits imposed on U.S. West Coast fishers force them to discard fish over their limits resulting in high discard rates."

Even if the United States started using a system similar to that in British Columbia, the challenge of dealing with overfished species may mean U.S. fisheries may never have discard rates as low as those of British Columbia, the authors say.

Such a change also would involve the cost of 100 percent observer coverage, although the authors write the costs may be outweighed by the benefits. "In many ITQ [individual transferable quotas] fisheries, increased profitability enables on-board observers to be funded from cost-recovery programs, increased retention of marketable fish would usually increase the profits of fishers and there may be considerable economic value attached to more accurate and reliable stock assessments."

Branch, who earned his doctorate from the UW with funding from the South African National Research Foundation and the U.S. National Marine Fisheries Service, is currently conducting marine assessment and management research at the University of Cape Town, South Africa.

Sandra Hines | EurekAlert!
Further information:
http://www.washington.edu

More articles from Ecology, The Environment and Conservation:

nachricht How does the loss of species alter ecosystems?
18.05.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

nachricht Excess diesel emissions bring global health & environmental impacts
16.05.2017 | International Institute for Applied Systems Analysis (IIASA)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>