Snow crab (Chionoecetes opilio) in the Barents Sea. Diet, biology and management

Abstract

This thesis seeks to develop a better understanding of snow crab (Chionoecetes opilio), a nonnative species that has established in the Barents Sea. Very little is known about the species role in the ecosystem, but it can be perceived both as a pest and as a goldmine. It is expected that the population will accommodate a significant fishery. As a non-native benthic crustacean spreading throughout a continental shelf shared between Norway and Russia, snow crab is legally a challenging management object. This thesis attempts to predict probable future distribution of the Barents Sea snow crab as well as ecosystem effects, and discuss management challenges. The research subject has been approached with a combination of a literature review and a diet study. Snow crab can potentially colonize most of eastern, central and northern Barents Sea. As an omnivorous benthic feeder it will likely affect important ecosystem processes, but the severity of snow crabs impact is unknown. It might in fact strengthen the pelagic-benthic coupling in the Barents Sea. As it seems that snow crab is a sedentary species, most of the commercial stock is currently Russian, but it is likely that it will spread into Norwegian zones soon. Two potential management strategies for the Barents Sea snow crab are discussed; “the pest strategy” and “the ecosystem based fishery strategy”.