Dual instrument passive acoustic monitoring of belugas in Cook Inlet, Alaska

J Acoust Soc Am. 2016 May;139(5):2697. doi: 10.1121/1.4947427.

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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustics / instrumentation*
  • Alaska
  • Animals
  • Beluga Whale / classification
  • Beluga Whale / physiology*
  • Echolocation* / classification
  • Environmental Monitoring / instrumentation*
  • Environmental Monitoring / methods
  • Equipment Design
  • Oceans and Seas
  • Porpoises / classification
  • Porpoises / physiology
  • Signal Processing, Computer-Assisted
  • Species Specificity
  • Time Factors
  • Transducers*
  • Vocalization, Animal* / classification
  • Whale, Killer / classification
  • Whale, Killer / physiology