Does the presence of a pop-up satellite archival tag affect movement of Tanner crab (Chionoecetes bairdi) in an exposed Alaskan bay?

Abstract

Fluctuating environmental conditions and crab population declines in the Bering Sea have elevated interest in pop-up satellite archival tags (PSATs) as a tool for investigating changes in crab spatial dynamics. However, PSATs are large relative to crab body sizes and may impact behavior which could limit their utility for informing management and conservation efforts. Accordingly, we tagged adult male Tanner crabs Chionoecetes bairdi with either a small acoustic tag (n = 20) or with both an acoustic tag and PSAT (n = 20) and monitored their movements within an acoustic receiver array in an exposed bay near Kodiak, Alaska. We evaluated several metrics intended to detect any between-group differences in movement or habitat use over the 78-day study. No group differences were observed, likely due to the small hydrodynamic forces acting on the PSAT relative to those acting on the crab. We encourage expanded use of PSATs in future crab research, but efforts should explore species-specific tag effects to help ensure accurate movement information is available for fishery management decisions.