Acoustic Moorings for Integrated Cetacean-Prey Studies
Abstract
Abstract: Proposed is the procurement of two new moorings that will enable concurrent, integrated cetacean-prey studies in the Southern California Bight (SCB). The proposed moorings will each consist of (1) a passive acoustic system for the study of cetaceans, (2) active acoustic systems for estimation of prey abundance, (3) conductivity-temperature-depth recorders for links to oceanographic water masses, and (4) a redundant acoustic release system. The passive acoustic system will be the High-frequency Acoustic Recording Package (HARP), mounted near the bottom of the mooring at approximately 1,000 m depth. The HARP is capable of continuous 320 kHz recording, allowing sufficient bandwidth for detecting all cetacean sounds found in the SCB, up to 6 months. The active acoustic system will consist of two multiple-frequency echosounders (AZVP units, ASL Environmental Sciences), one at full depth, just above the HARP, and the other 300 m from the surface. Both systems will have upward-looking 38 and 200 kHz echosounders. This will allow abundance estimation of krill and other baleen whale prey in shallow water, as well monitoring for daily movements and migrations, particularly of the deep-scattering layer. At depth, the echosounder will collect data to estimate biomass of prey (e.g. squid) for deep-diving cetaceans. Finally, conductivity-temperature-depth recorders (CTD, SeaBird MicroCAT SBE37-SM) will be deployed at the same depths as the active echosounder units. These moorings will enable the collection of long-term concurrent data on marine mammal presence and behavior in relation to prey fields and environmental features, which are currently very costly to obtain. The instruments will also support research projects for Scripps Institution of Oceanography’s graduate students and will allow training of well-rounded acoustician-ecologists capable of handling a broad range of ecosystem questions and studies.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141512858
Entities
People
- Ana Sirovic
Organizations
- Office of Naval Research
- United States Navy
- University of California, San Diego