Description
Summary:Passive acoustic monitoring is a key enabling technology in mitigating the effects of Naval activities on sound-sensitive cetaceans. The long-term goal of this research are to obtain and disseminate critical information for the design of acoustic monitoring systems. The specific objectives of this project are as follows: (1) develop and evaluate passive acoustic detection/classification methods for click and whistle sounds produced by deep-diving toothed whales; (2) examine the relationships among diving, acoustic behavior, habitat use, and group size and their implications for the acoustic detection and density estimation of toothed whales; and (3) correlate fine-scale oceanographic parameters with the foraging behavior of tagged whales to predict habitat suitability and movement patterns. The performance of an acoustic monitoring system depends not only on the system design and operating protocol, but also on the environment in which it is used and the behavior of the animals to be detected. This project furthers a pioneering integrated study that is focused on deep-diving cetacean species of particular concern to the Navy for which scant information is available regarding acoustic detectability. Tasks within the project are as follows: tagging and acoustic recording of beaked whales and pilot whales, study of their habitat choice and deep-foraging behavior, evaluation and application of acoustic detectors, and data archiving and sharing. The field work was concentrated in two areas with coastal populations of deep-diving toothed whales in the Canary Islands: Blainville's beaked whale and Cuvier's beaked whale off the island of El Hierro, and short-finned pilot whales off the island of Tenerife. In each site, we use three techniques: wide bandwidth acoustic recording buoys, visual surveys, and suction cup attached acoustic recording tags. We also are performing habitat assays in zones previously established as consistent foraging sites for beaked and pilot whales.