MARMAM subscribers,
We would like to bring to your attention the following recent
publication:
A New Context-Based Approach to Assess Marine Mammal
Behavioral Responses to Anthropogenic Sounds
W.T. ELLISON, B.L. SOUTHALL, C.W. CLARK, AND A.S. FRANKEL
Conservation Biology, Volume **, No. *, 1–8
2011, Society for Conservation Biology
published online: DOI: 10.1111/j.1523-1739.2011.01803.x
The link to the full article is http://onlinelibrary.wiley.com/doi/10.1111/j.1523-1739.2011.01803.x/full
The link to the abstract is http://onlinelibrary.wiley.com/doi/10.1111/j.1523-1739.2011.01803.x/abstract
and the abstract text is given below:
Abstract: Acute effects of anthropogenic sounds on marine
mammals, such as from military sonars, energy
development, and offshore construction, have received considerable
international attention from scientists,
regulators, and industry. Moreover, there has been increasing
recognition and concern about the potential
chronic effects of human activities (e.g., shipping). It has been
demonstrated that increases in human activity
and background noise can alter habitats of marine animals and
potentially mask communications for species
that rely on sound to mate, feed, avoid predators, and navigate.
Without exception, regulatory agencies
required to assess and manage the effects of noise on marine mammals
have addressed only the acute effects
of noise on hearing and behavior. Furthermore, they have relied on a
single exposure metric to assess acute
effects: the absolute sound level received by the animal. There is
compelling evidence that factors other than
received sound level, including the activity state of animals
exposed to different sounds, the nature and
novelty of a sound, and spatial relations between sound source and
receiving animals (i.e., the exposure
context) strongly affect the probability of a behavioral response. A
more comprehensive assessment method
is needed that accounts for the fact that multiple contextual
factors can affect how animals respond to both
acute and chronic noise. We propose a three-part approach. The first
includes measurement and evaluation
of context-based behavioral responses of marine mammals exposed to
various sounds. The second includes
new assessment metrics that emphasize relative sound levels (i.e.,
ratio of signal to background noise and
level above hearing threshold). The third considers the effects of
chronic and acute noise exposure. All three
aspects of sound exposure (context, relative sound level, and
chronic noise) mediate behavioral response, and
we suggest they be integrated into ecosystem-level management and
the spatial planning of human offshore
activities.
Keywords: behavioral context, noise, received level,
signal-to-noise ratio
Thanks and wishing everyone has a wonderful holidays,
William Ellison, Brandon Southall, Chris Clark, Adam Frankel
Brandon L. Southall, Ph.D.
President, Senior Scientist, SEA, Inc.
Research Associate, University of California, Santa Cruz
9099 Soquel Drive, Suite 8, Aptos, CA 95003, USA
831.332.8744 (mobile); 831.661.5177 (office); 831.661.5178 (fax)
Brandon.Southall@sea-inc.net; www.sea-inc.net