Temporal variation in the movement of the spiny lobster Jasus edwardsii

Abstract

Of 32 large spiny lobsters tracked with acoustic tags for 14–355 days in north-east New Zealand, 25 moved detectable distances (>0.1 km) from their tag site while being monitored. Individual lobsters moved up to 12.3 km over a 12-month period but the furthest distance from a tagging site was only 3.1 km. Maximum movement rates of 0.029 km day^–1 to 1 km day^–1 were recorded, but periods of elevated movement activity were interspersed with extended periods of little or no movement. Females were more active toward the end of the egg-bearing season around September and October. Males displayed two peaks in activity over the year, one in summer near the start of the new moult cycle, and another in winter following the mating season. The onset of elevated movement activity was often accompanied by a shift in the depth distribution of tagged lobsters, with 12 moving out to offshore sandflats and small, isolated, patch reefs. The results indicate that adult J. edwardsii have high site fidelity, spending extended periods in relatively small areas of inshore reef. However, lobsters leave their coastal reef sites during offshore movements that appear to be related to the moulting, reproductive and feeding cycles.