California’s marine mammals include 18 whale, 14 dolphin, six seal and one otter species. Each faces a myriad threats that can confound individual or population persistence. Among those threats are predation events by a variety of species. The cookie cutter shark is a small, deep water, tropical and sub-tropical pelagic shark that feeds as a micro-predator—removing small, typically sublethal bites. This species is known to feed on a variety of oceanic organisms that include squid, fishes, marine mammals, and other species. Since the cookie cutter shark is tropical and subtropical, the incidence of this species' predation attempts on California’s marine mammals would be expected to be low. However, marine mammal behaviors and an apparent change in the cookie cutter shark range has resulted in 79% of California marine mammals showing signs of predation events. These data represent a baseline understanding of the impact of this shark on California marine mammals.

Presentation will include graphic depictions of predation events.