Risk assessment of the harvested pike-perch population of the Azov Sea

We consider the fishery of pike-perch (Lucioperca lucioperca L.) in the Azov Sea, Russia. There are indications that this population might be threatened by the anthropogenic deterioration of environmental conditions. Since the species has an economic importance, extinction risk minimization is complemented by the consideration of optimal harvesting. The problem is therefore multicriteria. A stochastic simulation model is developed to assess simultaneously the annual yield and the extinction risk of the exploited population resulting from different harvesting strategies (i.e. combinations of harvesting efforts on yearlings and on adults). Another problem being considered is the assessment of the economic and ecological consequences of unintentional yearling catch. The model suggests that the current fishing rates induce a high risk of population abundance drop. Avoidance of yearling harvesting always improves both ecological and economical criteria. However, the extinction risk remains high even in the absence of fishing, suggesting that additional conservation measures are necessary to improve the environmental conditions. A simulation with slightly diminished salinity (by 0.5‰) drastically improves both the population viability and the annual yield.