Measuring Acoustic Noise around Kahoolawe Island.
Final rept. Feb 80-Mar 81,
NAVAL OCEAN SYSTEMS CENTER SAN DIEGO CA
Pagination or Media Count:
Seven SSQ-57A sonobuoys were monitored for seven hours from a P-3 aircraft during a surface gunfire operation north of Kahoolawe Island, Hawaii, in February 1980. Whale locations and activity were also monitored from the aircraft and from Maui Island during the exercise. Humpback whale Megaptera novaeangliae phonations dominated the ambient noise field during the exercise. The phonations fundamental components ranged between 100 Hz and 3 kHz. The calculated gunfire source level in the water was approximately 10 dB below the whales phonation level the gunshots peak energy was near 70 Hz. We saw whales swimming, lying still, diving, surfacing and, in two isolated instances breeching and lob-tailing. No standards exist to evaluate the effects of the noise on marine mammals. However, we cannot relate the movements and activities of whales observed during the exercise to any obvious airborne, surfaces or surface causes. Author