title: Behavioral responses of California sea lions to mid-frequency (3250-3450 Hz) sonar signals.
abstract: Military sonar has the potential to negatively impact marine mammals. To investigate factors affecting behavioral disruption in California sea lions (Zalophus californianus), fifteen sea lions participated in a controlled exposure study using a simulated tactical sonar signal (1 s duration, 3250-3450 Hz) as a stimulus. Subjects were placed into groups of three and each group received a stimulus exposure of 125, 140, 155, 170, or 185 dB re: 1 μPa (rms). Each subject was trained to swim across an enclosure, touch a paddle, and return to the start location. Sound exposures occurred at the mid-point of the enclosure. Control and exposure sessions were run consecutively and each consisted of ten, 30-s trials. The occurrence and severity of behavioral responses were used to create acoustic dose-response and dose-severity functions. Age of the subject significantly affected the dose-response relationship, but not the dose-severity relationship. Repetitive exposures did not affect the dose-response relationship.
authors.affiliation: National Marine Mammal Foundation, 2240 Shelter Island Drive, Suite 200, San Diego, CA 92106, USA. Electronic address: dorian.houser@nmmfoundation.org.
authors.forename: Dorian S
authors.initials: DS
authors.lastname: Houser
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Martin
authors.forename: James J
authors.initials: JJ
authors.lastname: Finneran
mesh_terms: D000161:Acoustic Stimulation; D000367:Age Factors; D000818:Animals; D001522:Behavior, Animal; D009622:Noise; D046070:Sea Lions / Q000502:physiology*; D013016:Sound
keywords: Acoustic exposure; Behavior; Behavioral response; CCA; Dose–response; MMP; Mammals; Marine Mammal Program; Noise; SPL; SSC; Sea lion; Space and Naval Warfare Systems Center; canonical correlation analysis; rms; root-mean-squared; sound pressure level