A BIOECONOMIC ANALYSIS OF THE SWEDISH FISHERY FOR NORWAY LOBSTER (NEPHROPS NORVEGICUS)

A modified version of Jones' length-based cohort analysis is linked to economic data from the Swedish trawl fishery for Norway lobster (Nephrops norvegicus). The current regulation implies a fishing practice where each landed lobster entails three killed due to discard mortality, and different cases of trawl selectivity are compared together with varying natural mortality. The bioeconomic analysis shows that a maximum economic yield equilibrium requires effort reductions of more than 50%, leading to a potential resource rent of almost US $3 million, compared to the open-access situation in 1995. Further increase of the resource rent is possible if a more selective trawl is introduced and enforced. The trawl fishery is compared with a minor in-shore creel fishery, which differs in exploitation pattern, fuel consumption, and impact on the benthic flora and fauna. A qualitative discussion on the two fisheries is carried out and a comparison of the economic performance is presented.Resource /Energy Economics and Policy,

Recorded captures of American lobster (Homarus Americanus) in Swedish waters and an observation of predation on the European lobster (Homarus Gammarus)

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Variability and connectivity of plaice populations from the Eastern North Sea to the Western Baltic Sea, and implications for assessment and management

An essential prerequisite of sustainable fisheries is the match between biologically relevant processes and management action. Various populations may however co-occur on fishing grounds, although they might not belong to the same stock, leading to poor performance of stock assessment and management. Plaice in Kattegat and Skagerrak have traditionally been considered as one stock unit. Current understanding indicates that several plaice components may exist in the transition area between the North Sea and the Baltic Sea. A comprehensive review of all available biological knowledge on plaice in this area is performed, including published and unpublished literature together with the analyses of commercial and survey data and historical tagging data. The results suggest that plaice in Skagerrak is closely associated with plaice in the North Sea, although local populations are present in the area. Plaice in Kattegat, the Belts Sea and the Sound can be considered a stock unit, as is plaice in the Baltic Sea. The analyses revealed great heterogeneity in the dynamics and productivity of the various local components, and suggested for specific action to maintain biodiversity