sgem08.pdf (461.73 kB)
Report of the Study Group on combining gear parameters into effort and capacity metrics (SGEM)
reportposted on 2008-01-01, 00:00 authored by ICESICES
The Study Group on combining gear parameters into effort and capacity metrics[SGEM] was poorly attended (only the Co‐Chairs were able to attend). This constrainedthe extent of the work that could be done. However, the Terms of Referencewere addressed as follows:a ) review work carried out on measuring relative/effective effort by geartype;The Co‐Chairs concluded that most previous work had treated gear type and to someextent, effort, in very general terms. Most previous work restricted consideration ofgear to a few generic categories, e.g. otter and beam trawls. SGEM considered thateffort should be based on actual effective effort i.e. swept‐area, and that this shouldconsider the characteristics of the gear and its deployment and be as detailed in timeand space as possible.b ) determine the relationship between vessel construction (tonnage, power,length etc.) and the size or quantity of fishing gear deployed;An example was presented from Scottish work. This revealed that the size of gear inthe Scottish otter trawl fleets was largely unrelated to the power of the vessel towingthe gear. Whereas this is probably not true for all fisheries or even this fishery historically,it does reveal that it must be emphasized not to make assumptions about thegear/vessel size relationship. Detailed information on gear deployed is only availablein restricted cases, these should be catalogued and analyses carried out where possible.c ) from métiers, which have been identified using formal analytical tools andexpert knowledge determine the relationship between key gear parametersand catch;The Co‐Chairs identified a number of candidate fisheries/métiers for further consideration.Four demersal otter trawl fisheries in the Northern North Sea (IVa) andCeltic Sea targeting mixed Nephrops/finfish and demersal fish; two pelagic otter trawlfisheries for mackerel in the North Sea and western waters and the gillnet fishery forhake in Western Waters (ICES Divisions VI and VII). A list of key physical and operationalparameters have been identified.d ) using the measurements/indicators developed, in conjunction with relevantAssessment Working Groups, apply these to pilot fisheries where differentgears are used to target the same species mix e.g. WGNSDS,WGNSSK, WGSSDS, WGHMM.The Co‐Chairs proposed that a number of case studies be examined. These includeotter trawl demersal and pelagic fisheries in Scotland and Ireland. Other valuablecase studies would include shrimp trawls in Iceland, as well as a beam trawl example.Other gears that would be worth investigating would be gillnets, longlines andseines. In some cases these would suitable for use as pilot studies as defined in ToRd).
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