How do environmental signals influence marine mammal habitat use in the Bering Sea?
This research makes synoptic measurements of cetacean habitat use, prey concentrations, physical oceanographic processes, and noise levels in the Bering Sea. Integrated data such as these will be vital in understanding the relationship between cetaceans and their environment both in the presence and absence of specific noise sources. This is crucial component for evaluating the effect of human activity in marine mammal habitats. Evaluation in areas like the Bering Sea is especially critical because global climate change can lead to rapid changes of an entire ecosystem. Progressive climate change has the potential to alter areas of the Arctic that have been previously unavailable for human use. Long-term measurements will play an important role in determining if human activities could impact the delicate Arctic ecosystem, in identifying the point at which the cumulative effects of the environment and human activities impact a population, and in identifying the kinds of exposure that pose the greatest risk.
Are passive acoustic sub-sampling techniques effective for detecting marine mammals?
Passive acoustic technology has revolutionized the study of marine mammals in their natural habitat by non-invasively providing information on a vocalizing animalís presence, species, behavior, and position, extending our ability to detect their interactions and movements while they are underwater. The power of continuous passive acoustic monitoring is the comprehensive capturing of local environmental sound over the recording systemís usable frequency range. One of the drawbacks of continuous acoustic recording is the vast amounts of data generated and the time necessary to analyze the recordings. Automated detection algorithms have reduced the time required for data analysis, but sensor power requirements and data storage space often limit the duration of continuous recordings. Passive Aquatic Listening (PAL) instruments operate according to an adaptive sampling protocol and have previously been used to quantify marine precipitation, wind intensity and ambient sound levels. The goal of sub-sampling with an adaptive sampling protocol is to overcome hardware limitations by reducing the amount of data acquired, while maintaining a high probability of detection and classification of targeted signals.
How do humpback whale and North Atlantic right whale dive patterns relate to regional prey movements?
The main question addressed by this work is whether dive profile depths correlate with regional prey distribution patterns. This is a collaborative effort with Dr. Susan Parks (ARL Penn State).