Efficacy of conservation measures for the American lobster: Reproductive value as a criterion

Abstract

Reproductive value takes into account both current and future value, effectively characterizing the value of an individual to the population. In this study, we use reproductive value as a criterion to evaluate the effectiveness of several conservation measures that have been undertaken or proposed for the American lobster (Homarus americanus) fishery in Newfoundland. These measures are slot fishing (i.e. no fishing below or above certain sizes), marine protected areas (MPAs), V-notching, and window fishing (i.e. no fishing within a size window). Reproductive value was estimated by using catch length data available from commercial fisheries and research surveys. We found that MPAs had the greatest effect, followed by V-notching and slot-fishing. MPAs resulted in an average increase of 64.9 in total reproductive value, V-notching an average increase of 18.3, and slot fishing an average increase of 16.8. In general, window fishing was not effective unless the size of the window was large. For instance, an average increase of 8.7 in total reproductive value would require a wide window (100-129 mm). Our results provide a scientific basis for evaluating conservation measures in a way that integrates population demographical information with information from commercial fisheries and research surveys. © 2012 International Council for the Exploration of the Sea. Published by Oxford University Press. All rights reserved.