A telemetric study of the home ranges and homing routes of copper and quillback rockfishes on shallow rocky reefs

Abstract

Ultrasonic telemetry was used to investigate the home ranges and homing routes of copper, Sebastes caurinus, and quillback, Sebastes maliger, rockfishes. Home ranges were small (most <10m2) on high relief reefs and considerably larger (within 4000m2) on low relief reefs. No off-reef movement was detected on either reef type. Daily positions of rockfishes were monitored as they proceeded back to their home sites after 500m displacements from a high relief rocky reef to a low relief rocky reef. Six of 7 displaced copper and quillback rockfishes took 8-25 days to return home. Once displaced rockfish returned to their original capture site, no subsequent movement was detected, suggesting home site recognition. Homing seemed to consist of 3 phases: 1) initial movements along a bimodal NW-SE axis that are possibly associated with directional preferences in exploratory migrations; 2) movement (westerly) towards the home reef; and 3) the final location of the home site. -from Author