Report of the Study Group on Nephrops Surveys (SGNEPS)
This article was originally published by ICES on their website http://www.ices.dk/. peer-reviewed The Study Group on Nephrops Surveys (SGNEPS) met in Ancona, Italy from 6–8 March 2012. The group consisted of 12 scientists from Ireland, Scotland, England, Northern Ireland, Spain, Denmark, Portugal an...
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| Format: | Report |
| Language: | English |
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International Council for the Exploration of the Sea (ICES)
2013
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| Online Access: | http://hdl.handle.net/10793/863 http://www.ices.dk/sites/pub/Publication Reports/Expert Group Report/SSGESST/2012/SGNEPS12.pdf |
| Summary: | This article was originally published by ICES on their website http://www.ices.dk/. peer-reviewed The Study Group on Nephrops Surveys (SGNEPS) met in Ancona, Italy from 6–8 March 2012. The group consisted of 12 scientists from Ireland, Scotland, England, Northern Ireland, Spain, Denmark, Portugal and Italy under the chairmanship of Colm Lordan, Ireland. SGNEPS has an important role as the international coordina-tion group for Nephrops UWTV surveys in the North Atlantic and Mediterranean. Heretofore SGNEPS has focused on planning, protocols, quality control, design and survey development issues. At the 2012 meeting group compiled a table summarizing the station densities and precision levels of most annual Nephrops UWTV surveys. Large variations in survey station densities occur across the grounds currently sur-veyed. Station density, accuracy and precision trade-offs were investigated and dis-cussed in detail for the two main survey design types (random stratifies and grids). The main outcome of these deliberation was that a minimum precision level of <20% CV (also known as Relative Standard Error) should be attained for these types of surveys. There may be operational reasons why individual surveys should aim for higher precision than that (e.g. to ensure good coverage and accurate burrow surfac-es). In some areas station densities could be reduce to allow for improved coverage to previously unsurveyed Nephrops grounds. Progress towards integrated stock assess-ments for Nephrops which make use of all sources of fisheries dependent and inde-pendent information was reported to the group. There was consensus that the current ICES framework for assessing and providing catch options based on the UWTV sur-veys remains the most appropriate methodology for the moment. There has been significant progress since WKNEPH (ICES, 2007) in addressing many of the per-ceived uncertainties in the methodology. The remaining assumptions on burrow occupancy, burrow size, growth, discard survival can only be addressed through ... |
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