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dc.contributor.authorUlltang, Øyvind
dc.date.accessioned2011-09-06T13:10:16Z
dc.date.available2011-09-06T13:10:16Z
dc.date.issued1979
dc.identifier.citationThis report is not to be quoted without prior consultation with the General Secretary.en_US
dc.identifier.urihttp://hdl.handle.net/11250/103439
dc.description.abstractMesh assessments are usually carried out by calculating "short term losses" and "long term gains" expected from a change in the minimum legal mesh size, assuming no change in total fishing effort or its distribution by area and season (Gulland, 1961) • At the time these methods were developed, minimum legal meshand/ or landing sizes were the only regulatory measures applied on most demersal trawl fisheries. After the introduction of TACs one is faced with the problem of what effect a change in mesh size should have on the recommended TAC. Often this has been dealt with by simply calculating the catches corresponding to a range of fishing mortalities for the alternative mesh sizes and recommend TAC's corresponding to a certain value of the fishing mortality on the fully exploited age groups, identical for all mesh sizes. By this approach the "short term loss" is automatically transferred into the TAC, making the TAC for an increased mesh size smaller than the TAC for the present mesh size by an amount approximately equal to "short term losses". After a brief discussion of the assessment of short and long term effects of mesh size changes, this paper will mainly deal with the appropriateness or in-appropriateness of the usual methods applied for selecting TAC's and discuss alternatives.en_US
dc.language.isoengen_US
dc.publisherICESen_US
dc.relation.ispartofseriesICES CM Documents;1979/G:56
dc.titleSome comments to the problem of adjusting TACs to mesh size changes.en_US
dc.typeWorking paperen_US
dc.subject.nsiVDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Catch: 925en_US
dc.subject.nsiVDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Aquaculture: 922en_US
dc.source.pagenumber17 s.en_US


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