Diving behaviour of harbour porpoises, Phocoena phocoena

Mean dive depths and duration ranged from 14±16 to 41±32 m, and from 44±37 to 103±67 s, respectively. The maximum recorded dive depth and duration was 226 m and 321 s. This performance may not represent the maximum capacity of harbour porpoises but rather the maximum depth of the study area. Individual dives had similar rates of descent and ascent. Two porpoises with monitoring periods >2days demonstrated a diel pattern in their diving, making fewer, but deeper dives at nights. In the Bay of Fundy, porpoises made between 22 and 70% of dives to depths (range 20-130 m) where the majority of entanglements in ground fish gill nets were reported. -from Authors

Duke Scholars

Author Andrew J Read Marine Science and Conservation