Distribution and Demographics of Marine Mammals in SOCAL Through Photo-Identification, Genetics, and Satellite Telemetry: A Summary of Surveys Conducted 15 June 2010 - 24 June 2011

摘要

In the first year of a three-year project, from June 2010 to June 2011 small boat-based surveys for cetaceans were conducted in the U. S. Navy's SOCAL training range, particularly in the Southern California Anti-Submarine Warfare Range (SOAR) and the Southern California Offshore Range (SCORE) centered on San Clemente Island in the Southern California Bight. Surveys included species verification tests, photo-identification, satellite tagging, and biopsy sampling. Because of their apparent sensitivity to Mid-Frequency Active Sonar (MFAS) throughout the world, beaked whales--Cuvier's, in particular--and fin whales were the primary target species. During 33 surveys conducted during the study period (including in January and May, times not previously surveyed by small boat in this area), 164 groups of cetaceans were encountered at or near SOAR. To address distribution and habitat use, 20 satellite tags (some with depthreporting capability) were deployed on 6 species. Depth-reporting tags on Cuvier's whales recorded multiple dives > 2000 m and > 2 hours, both deeper and longer than previously reported for this species. Preliminary results of photo-identification data (supplemented by satellite tag data) suggest that Cuvier's and fin whales both may have population sub-units with higher than expected residency in the Southern California Bight. Comparison of movement and dive behavior of tagged whales with concurrent MFAS exercises at SCORE is underway.