Characterizing snow crab (<i>Chionoecetes opilio</i>) movements in the Sydney Bight (Nova Scotia, Canada): a collaborative approach using multiscale acoustic telemetry

Abstract

Like many deeper ocean species, the fine-scale movement ecology of snow crab is not well understood. We integrated fine-scale positioning telemetry with larger-scale position estimates from autonomous mobile surveys and harvester returns to evaluate movements of male and female snow crab (Chionoecetes opilio). Effects of life stage–sex, temperature, and diel and tidal cycles on movement velocity were observed, with a tendency for increased velocities during the night, slack tide, and at increasing water temperatures. Males also moved faster than females and juveniles. The strength of these statistical relationships, however, was weak (R 2 = 7.2%). The movement direction also did not vary over the tidal cycle. The maximum distance moved for adult males was an order of magnitude higher (37.1 km) than for females (3.6 km) and juvenile males (3.9 km), but median distances were more similar across groups. Individuals, once released, tended to disperse and move toward slope habitats. Little evidence of site fidelity was apparent. The absence of strong environmental influences on movements likely reflected the behavioural plasticity of snow crab and the relative environmental stability of offshore environments.