Watch your stock! A warning about the endorsement of the " Stock concept " adopted by the STOCKMED project for the Mediterranean groundfish fisheries

The " Stock " concept represented a " Mare incognitum " in the Mediterranean groundfish fisheries science for decades until its recent implementation within an European Union (EU) project (STOCKMED; 2012). Results presented in the final report approved in 2015, indicate the presence of a low number of " Stock units " (from 3 up 7) in a large area covering a subset of the 27 Geographical sub areas (GSA) recognized for the Mediterranean Sea. The Scientific, Technical and Economic Committee for Fisheries (STECF) partially endorsed STOCKMED suggestions, using them to carry out fisheries assessments in joined GSA. Present contribution suggests great caution in following such a procedure without a preliminary investigation of the Intra-STOCKMED heterogeneity, taking into account current GSA limits. STOCKMED undoubtedly represents a milestone in the history of fishery science; however, the extended entities referred to as " Stocks " in that report rather should be considered as Populations for fisheries management purposes, i.e. a more homogeneous segments of a given species distributed in part of the species' areal in a Large Marine Ecosystem (LME), the Mediterranean Sea in the specific case. On the contrary, Stocks should be defined as operational arbitrarily and fisheries oriented Entities suitable for short - term assessment and management.