Assessment of indicator trends related to exploited demersal fish populations and communities in the Mediterranean
Since 1994, Mediterranean research organisations have carried out yearly standardized bottom trawl surveys along the coasts of the Mediterranean Sea from Gibraltar to the Aegean Sea (Medits surveys). A dynamic indicator-based approach to the assessment of multi-stock fisheries has been applied to the data series obtained from these surveys by an international working group involving all the scientific teams contributing to the data collection process. The application was done according to the 13 GFCM geographical sub-areas sampled by the Medits surveys. While reference points for a lot of fished populations and community indicators are seldom available, reference directions are well established for some indicators, giving guidelines for fishery management. A set of simple indicators related to fishing impact on fish populations and communities were estimated from the Medits time-series data (population abundance, average length and maturity length, community total biomass and number, average length and weight). Trends in these indicators were assessed within a hypothesis testing framework. The results of the assessments were summarized in tables scoring increasing and decreasing trends to draw attention on the changes in the fish community.
Keyword(s)
Mediterranean, Bottom trawl survey, Community, Fish population, Indicator
MEDITS (2007). Assessment of indicator trends related to exploited demersal fish populations and communities in the Mediterranean. Ref. DCR Medits Working group. Nantes (France), 15-18 March 2005 and Kavala (Greece), 2-6 April 2006.. https://archimer.ifremer.fr/doc/00000/2198/