Movements and diving of grey seal females ( Halichoerus grypus ) in the Gulf of St. Lawrence, Canada

Abstract

Five female grey seals were tracked with satellite-linked time-depth recorders during September to April 1993–1994. Seals remained in the northern Gulf of St. Lawrence (Gulf) for 1–2.5 months after capture. Four females dove primarily to depths <10 m and 20–70 m, while all dives of the fifth female, a blind animal, were <10 m. During October/November, all animals moved into the southern Gulf or onto the Scotian Shelf. This migration lasted 6–10 days, during which time animals covered 350–800 km. During that migration, all females, including the blind animal, dove up to 100 m, but the majority of dives were to depths of 40–70 m. Two seals stayed in the southern Gulf through the winter while the others left the Gulf in January. When in the southern Gulf and on the Scotian Shelf, dive depths and bathymetry information indicated that dives were to the bottom.