Selected papers presented at the Workshop on biological reference points



The workshop stressed that the concept of reference points (RPs) needs to be closely connected to the management objective of concerned fisheries, taking into account various parameters such as maximum sustainable yield, economic and social benchmark and environment concern. Participants stressed the need to define different RPs for each dimension of management or to identify a single RP aimed at ensuring the sustainability of the system, thereby no longer limited to biological aspects. A review of possible approaches to setting RPs and indicators for Black Sea fisheries emphad the dynamic nature of recent ecosystem changes. The traffic light approach was illustrated as a means of following dynamic changes and gaining a broad perspective on events at the ecosystem level. The workshop outlined the main RPs obtained by applying the bio-economic optimization models of effort and effort-catch as derived from the theory of population dynamics. For the Mediterranean Sea, it was recommended to adopt a multicriteria approach based on bio-economic optimization models which, by introducing a number of constraints, would allow the definition of the actual state of the system as well as specific management targets. The use of some indicators derived from bottom trawl surveys carried out in the Adriatic Sea highlighted the potential suitability of selected indicators of their estimators. In the case of large pelagic species, it was confirmed that time series of both longline catch per unit effort and recruitment indexes can be considered as RP for these species. The use of a biological RP based on exploitation rate threshold was appraised for the stocks of anchovy and sardine in the central and northern Adriatic Sea and the workshop pointed out that it could be used to prevent stock collapse along with the minimum biological acceptable level based on spawning stock biomass.