An analysis of substrate selection by postlarval American lobsters, Homarus americanus, using a dynamic optimization model

During the fourth stage of larval development the American lobster (Homarus americanus) leaves the plankton and becomes benthic. Before final settlement lobsters sample different substrates which may be accepted or rejected. Upon rejection the lobster returns to the plankton before sampling another substrate. In this paper we present a model of the substrate selection behavior of settling lobsters using dynamic optimization techniques. The model examines the role of substrate quality and availability, postlarval testing of substrates, and mortality associated with testing substrates, upon the decision to accept or reject the substrates sampled and predicts the eventual importance of each substrate in the recruitment of lobsters to reproductive age. Finally we apply the model using recent data on long-term survival of lobsters in the field. The model predicts that the high quality substrate (cobble) accounts for most of the adult lobster population, in spite of the much greater abundance of other, more marginal, substrates.