Report of the Working Group for North-east Atlantic Continental Slope Survey (WGNEACS)
The present report was prepared by the Working Group on the North-east Atlantic Continental Slope Survey (WGNEACS) in ICES, Copenhagen, from 14–16 June 2011. WGNEACS reviewed the possibilities provide the following community indices for deep-water species; i)Proportion of fish larger than the mean s...
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| Format: | Text |
| Language: | English |
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2011
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| Online Access: | https://archimer.ifremer.fr/doc/00078/18931/16520.pdf https://archimer.ifremer.fr/doc/00078/18931/ |
| Summary: | The present report was prepared by the Working Group on the North-east Atlantic Continental Slope Survey (WGNEACS) in ICES, Copenhagen, from 14–16 June 2011. WGNEACS reviewed the possibilities provide the following community indices for deep-water species; i)Proportion of fish larger than the mean size of first sexual maturation, ii) mean maximum length across all species found in research vessel surveys. iii) 95th % percentile of the fish length distribution observed in research vessel surveys. In deep-water surveys, length frequency data are widely available, however information on age and reproductive state are available for fewer species. In addressing WGNEACS thought it was useful first to identify those species for which this information is available. Also a case study regarding i-iii for roundnose grenadier was performed. Last’s years meeting identified three subgroups of existing deep-water surveys and new survey requirements (proposals) that were grouped by geographical area, a Nordic, a central and a southern subgroup. At this year’s meeting, these three subgroups received a set of specific terms of references to work with. The Nordic subgroup dealt with deep-water trawl surveys that are currently undertaken by Norway, Iceland, Faroe and Greenland. The subgroup continued the evaluation on the sampling protocols of the existing Nordic deep-water surveys with the aim to standardize them as much as possible. Similarities and differences in sampling design and protocols were highlighted. A set of recommendations were made to the Nordic national laboratories on last meeting in order to improve coordination of surveys. The state of this coordination was evaluated. To share data and initiate joint data analysis and research, a data exchange format was agreed upon at the 2010 meeting and abundance data from four target species (Greenland Halibut, Greater Silver smelt, Beaked Redfish and Roundnose Grenadier) were combined from all Nordic deep-water surveys. Standardized swept-area estimates were updated at the ... |
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