Home range dynamics of the American lobster, Homarus americanus

Abstract

A fixed array ultrasonic telemetry system was used to track the fine scale movements of American lobsters, Homarus americanus, within a large enclosure (mesocosm, 3125 m2). Positions of lobsters were obtained continuously, at 5 min intervals, for an average of 4.1 days. A kernel method was used to estimate the daily home ranges (95% utilization distribution, UD), core areas of activity (50% UD) and distance traveled by each lobster. The mean home range size for all lobsters was 760.1 ± 132.0 m2 (n = 32), and the average core area was 74.0 ± 10.9 m2. Home range size was closely correlated with the daily distance traveled by lobsters (523.2 ± 78.1 m day−1; r 2 = 0.62, p = 0.0001). Within the size range of lobsters used in this study (62–93 mm carapace length), there was no correlation between the lobster sizes and the areas of their home ranges. Lobsters changed core areas and home ranges often, occupying 1.4 ± 0.1 different core areas each day. However, despite changing their core areas, the size of their home ranges remained fairly consistent from one day to the next. These data illustrate both the residential and the nomadic nature of lobster movements and demonstrate the utility of fixed array ultrasonic telemetry for quantifying the fine-scale movements of lobsters.