Description
Scottish Marine and Freshwater Science Vol 8 No 17
This document reports on the outcomes of a workshop held at Marine Scotland Science, Marine Laboratory, Aberdeen in April 2016. The workshop was convened to examine Version 1 of the Groundfish Survey Monitoring and Assessment (GSMA) data product and revue the methods used to derive it. This data product was derived to support assessment of the state of fish species and communities, and the role of fish in the structure and functioning of marine food webs across the entire Northeast Atlantic region, from Norway to Gibraltar. As such, the data product was intended to meet the monitoring programme obligations of European Union Member States bordering the Northeast Atlantic region under the Marine Strategy Framework Directive. The job of the workshop was to ensure that the GSMA data product was fit for this purpose; that it could indeed meet the data needs necessary to calculate all fish species and community related indicators used in the upcoming OSPAR Interim Assessment 2017 (IA2017), as well indicators likely to be needed in future assessment cycles. The workshop concluded that the data product was indeed fit for the purpose intended. Some minor issues in methodology were identified. These have subsequently been addressed, the methodology documentation (Moriarty et al. 2017) updated to reflect these changes, and a Version 2 data product produced. The Version 2 GSMA data product also takes into account any updates made by national data providers to the database held on the DATRAS portal over the intervening period between the download from which Version 1 was derived and up to approximately the end of October 2016 when data were downloaded to derive the Version 2 data product. The main part of this document then proceeds to describe the content of the Version 2 GSMA data product. For each survey’s standard monitoring programme (excludes samples collected before survey protocols became fully established and trawl samples of extreme short and extreme long tow duration: see Moriarty et al. (2017) for further details), a series of diagnostic plots is presented that display the variation in, and relationships between, a range of key parameter values, temporal trends in sampling effort, and sampling frequency distributions for each ICES statistical rectangle covered by the survey. Charts are provided showing the locations of all trawl samples collected by each survey’s standard monitoring programme. Two criteria for the inclusion of ICES statistical rectangles as part of each surveys standard survey area are presented. These include a new criterion not used in Moriarty et al. (2017) aimed at ensuring that, not only are rectangles sampled reasonably frequently, but that they are also sampled regularly throughout the course of each survey’s time series. The consequences of applying these two criteria are explained and resulting standard survey areas for each individual survey data product are illustrated.