FY 2003

Future directions for acoustic marine mammal surveys: Stock assessment and habitat use—Report of a workshop held in La Jolla, California, 20–22 November 2002

Mellinger, D., and J. Barlow, co-convenors

NOAA OAR Special Report, NTIS: PB2003-104277, NOAA/OAR/PMEL, Seattle, WA, 38 pp (2003)

Although acoustics has been used for studying marine mammals for decades, it has seldom been employed for assessing populations. The term assessment is used here to describe the process of evaluating the status of a population relative to some management goal. Assessment involves studies of the structure of populations, estimation of abundance and trends in abundance, and the evaluation of anthropogenic impacts. The best example of the use of acoustics in assessment to date is the long-term study of the Beaufort Sea bowhead whale population, where combined visual and acoustic methods have significantly improved the population estimate. The primary goal of this workshop was to explore how acoustic methods might be more fully exploited for marine mammal assessment—that is, how might acoustic methods provide assessment data unobtainable in other ways? In what ways might acoustic methods provide roughly equivalent data at less cost? A secondary goal was to explore how acoustic methods can be used to address the questions of how marine mammals respond to noise, especially anthropogenic noise, and how effective any mitigation measures might be.