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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. [ABSTRACT FROM AUTHOR]

The endangered beluga whale (Delphinapterus leucas) population in Cook Inlet, AK faces threats from a variety of anthropogenic factors, including coastal development, oil and gas exploration, vessel traffic, and military activities. To address existing gaps in understanding about the occurrence of belugas in Cook Inlet, a project was developed to use passive acoustic monitoring to document the year-round distribution of belugas, as well as killer whales (Orcinus orca), which prey on belugas. Beginning in June 2009, ten moorings were deployed throughout the Inlet and refurbished every two to eight months. Despite challenging conditions consisting of strong tidal currents carrying debris and seasonal ice cover, 83% of mooring deployments were successfully recovered. Noise from water flow, vessel traffic, and/or industrial activities was present at several sites, potentially masking some signals. However, belugas were successfully detected at multiple locations. Detections were relatively common in the upper inlet and less common or absent at middle and lower inlet locations. Killer whale signals were also recorded. Some seasonal variability in the occurrence of both belugas and killer whales was evident. [ABSTRACT FROM AUTHOR]

We present the first peer-reviewed wild beluga, Delphinapterus leucas, whale ethogram, a comprehensive description and definition of behavioral states and events exhibited by the endangered stock of Cook Inlet beluga whales (CIBWs). The ethogram can be used to help quantify beluga behaviors and increase the utility of future and ongoing beluga behavioral studies, in Cook Inlet and for other populations. We tested the applicability of the ethogram by quantitatively examining spatial, temporal, and environmental effects on the probability of observing specific beluga behaviors in Eagle Bay and Eagle River (Knik Arm, Cook Inlet). Behaviors were observed and recorded from 2007 to 2011 between May and December when belugas are known to forage in the study area. We found that CIBWs are generally more likely to travel than mill in Eagle Bay, except when the tide is ebbing and above its midpoint, and that traveling occurred more frequently in Eagle River than in either the north or south sections of the bay. The results of our quantitative behavioral analysis can be compared with anecdotal observations of whale activity in the bay, and we encourage further investigation to more fully explain our results. The explicit language used to define this beluga ethogram will facilitate a more standard approach to behavioral studies of CIBWs, provide a means to quantify the response of CIBWs to anthropogenic activities, and allow comparison among multiple populations. Thus, this CIBW ethogram will potentially promote innovative approaches to help manage the endangered CIBW population. [ABSTRACT FROM AUTHOR]