—a family group within the pinnipeds that includes all of the “true” seals (i.e., the “earless” species). Generally used to refer to all recent pinnipeds that are more closely related to Phoca than to otariids or the walrus.


—one of a group of acquatic, mostly marine, carnivorous animals; includes seals, sea lions, and walruses; all their limbs are finlike and they spend at least some time on land or ice.

Permanent Threshold Shift (PTS)

—prolonged exposure to noise causing permanent hearing damage.


—an increased behavioral (or physiological) responsiveness occurring over time, as an animal learns that a repeated or ongoing stimulus has significant consequences. Cf. habitutation.


Richardson et al., 1995.

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