Resident and dispersal behavior among individuals within a population of American lobster Homarus americanus

Various biases and limitations associated with mark-recapture research have resulted in conflicting interpretations of individual movement patterns, rendering unclear the selective pressures that could be responsible for structuring populations and influencing individual behavior patterns in the marine environment. To address these issues, novel modeling techniques developed for mammalian systems were applied to trajectory data from an American lobster Homarus americanus population in order to describe quantitatively seasonal movement patterns. Basing individual- and population-level analyses on a correlated random walk model, individuals were found to belong to 1 of 2 movement types: residents or dispersers. Over the course of a year, resident animals remained in the general area of their release, whereas dispersing animals moved rapidly away from release sites in autumn and slowly returned in spring. Such movement patterns can be explained as responses to seasonal limitations in hard-substrate habitat. The effect of movement on the seasonal population distribution and structure of lobsters can have significant consequences for the sustainable exploitation of the species.