Abstract
European lobsters have declined steadily in abundance over the past 30-50 years, and several restrictions have been made to lobster fisheries already. New regulations are suggested, such as reduced time window for pot-fisheries, moratoria on berried females, and no-take Marine Protected Areas (MPA) to facilitate lobster recoveries. Recently, new techniques in capturing and observing larval lobsters, and successful acoustic tracking of individual lobsters over long time periods have increased our information about basic lobster biology. Ongoing activities to estimate efficiency of lobster traps are also filling in new information into existing gaps. We now believe time is mature to launch modelling activities on this important resource, which may also be useful to better managing other decapods, such as the King crab, taking an approach including bottom-up mechanisms and human actions such as harvesting and management. We suggest an individual-based modelling approach as particularly suitable for organisms like lobsters, where each individual of reasonably well defined populations can be followed through their life cycle. With an IBM, we can build from individual-level processes of environment, foraging, physiology, behaviour, interactions, dispersal, recruitment and harvesting, obtain population-level output, such as density-dependence, yield and efficiency of various harvesting and management practices. We will develop an IBM, in close collaboration with field-oriented lobster biologists and larval ecologists. Then, we will apply the model to explore important management questions, such as interactions between environmental settings (larval drift and dispersal, habitat structure and topography, temperature), and regulation options (total effort, seasonal closure, MPA, size-limitations etc.). In addition, we plan to perform an evolutionary assessment of how harvesting pressure and particular regulations may lead to long term adaptive changes in lobsters.
Norway