SEA Blog

"Layperson" summary of B. Southall presentation on new acoustic system initiative available

The 161st meeting of the Acoustical Society of America will take place in Seattle, WA later this month.  Dr. Brandon Southall, SEA Inc. president, will give three technical presentations at this meeting, one of them entitled: "Listening to the Ocean and Marine Life Using a Fiber-Optic Monitoring System"  The concept is the integration of acoustic monitoring systems into a state-of-the-art fiber-optic cabled system being deployed off Washington and Oregon for the next 25 years.  A "layperson" summary of the presentation was prepared for general public and media interest in the subject, which is available at:

http://www.aip.org/asa_laypapers2011/Southall.html

New paper on predator-prey interactions - beaked whales in the Bahamas

A new paper entitled "The Relationship among Oceanography, Prey Fields, and Beaked Whale Foraging Habitat in the Tongue of the Ocean" was just published in PLosOne.  This excellent work was part of our multidisciplinary collaboration to study marine mammal biology and behaivoral responses in the Bahamas in 2007-08 <see: http://www.sea-inc.net/science/#brs>

You can get the full text of the paper (Open Access) by Elliot Hazen et al at the below link; the paper abstract is copied below as well.

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0019269

Abstract
Beaked whales, specifically Blainville's (Mesoplodon densirostris) and Cuvier's (Ziphius cavirostris), are known to feed in the Tongue of the Ocean, Bahamas. These whales can be reliably detected and often localized within the Atlantic Undersea Test and Evaluation Center (AUTEC) acoustic sensor system. The AUTEC range is a regularly spaced bottom mounted hydrophone array covering .350 nm2 providing a valuable network to record anthropogenic noise and marine mammal vocalizations. Assessments of the potential risks of noise exposure to beaked whales have historically occurred in the absence of information about the physical and biological environments in which these animals are distributed. In the fall of 2008, we used a downward looking 38 kHz SIMRAD EK60 echosounder to measure prey scattering layers concurrent with fine scale turbulence measurements from an autonomous turbulence profiler. Using an 8 km, 4-leaf clover sampling pattern, we completed a total of 7.5 repeat surveys with concurrently measured physical and biological oceanographic parameters, so as to examine the spatiotemporal scales and relationships among turbulence levels, biological scattering layers, and beaked whale foraging activity. We found a strong correlation among increased prey density and ocean vertical structure relative to increased click densities. Understanding the habitats of these whales and their utilization patterns will improve future models of beaked whale habitat as well as allowing more comprehensive assessments of exposure risk to anthropogenic sound.