title: Dual instrument passive acoustic monitoring of belugas in Cook Inlet, Alaska.
abstract: As part of a long-term research program, Cook Inlet beluga (Delphinapterus leucas) presence was acoustically monitored with two types of acoustic sensors utilized in tandem in moorings deployed year-round: an ecological acoustic recorder (EAR) and a cetacean and porpoise detector (C-POD). The EAR was used primarily to record the calls, whistles, and buzzes produced by belugas and killer whales (Orcinus orca). The C-POD was used to log and classify echolocation clicks from belugas, killer whales, and porpoises. This paper describes mooring packages that maximized the chances of successful long-term data collection in the particularly challenging Cook Inlet environment, and presents an analytical comparison of odontocete detections obtained by the collocated EAR and C-POD instruments from two mooring locations in the upper inlet. Results from this study illustrate a significant improvement in detecting beluga and killer whale presence when the different acoustic signals detected by EARs and C-PODs are considered together. Further, results from concurrent porpoise detections indicating prey competition and feeding interference with beluga, and porpoise displacement due to ice formation are described.
authors.affiliation: National Marine Mammal Laboratory, Alaska Fisheries Science Center, National Oceanic and Atmospheric Administration, 7600 Sand Point Way Northeast, Seattle, Washington 98115, USA.
authors.forename: Manuel
authors.initials: M
authors.lastname: Castellote
authors.affiliation: Division of Wildlife Conservation, Alaska Department of Fish and Game, 1255 West 8th Street, Juneau, Alaska 99811, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Small
authors.affiliation: Hawaii Institute of Marine Biology, University of Hawaii, 46-007 Lilipuna Road, Kaneohe, Hawaii 96744, USA.
authors.forename: Marc O
authors.initials: MO
authors.lastname: Lammers
authors.affiliation: Division of Wildlife Conservation, Alaska Department of Fish and Game, 1255 West 8th Street, Juneau, Alaska 99811, USA.
authors.forename: Justin J
authors.initials: JJ
authors.lastname: Jenniges
authors.affiliation: Division of Wildlife Conservation, Alaska Department of Fish and Game, 1255 West 8th Street, Juneau, Alaska 99811, USA.
authors.forename: Jeff
authors.initials: J
authors.lastname: Mondragon
authors.affiliation: School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, 17101 Point Lena Loop Road, Juneau, Alaska 99801, USA.
authors.forename: Shannon
authors.initials: S
authors.lastname: Atkinson
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D000413:Alaska; D000818:Animals; D050643:Beluga Whale / Q000145:classification / Q000502:physiology*; D004455:Echolocation / Q000145:classification; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D009792:Oceans and Seas; D019576:Porpoises / Q000145:classification / Q000502:physiology; D012815:Signal Processing, Computer-Assisted; D013045:Species Specificity; D013997:Time Factors; D014159:Transducers; D014828:Vocalization, Animal / Q000145:classification; D050685:Whale, Killer / Q000145:classification / Q000502:physiology