Southall Environmental Associates, Inc.


SOCAL-14 continues a multi-year effort (2010-2015) called the “SOCAL-BRS” (Southern California Behavioral Response Study). This project is designed to better understand the behavior of numerous protected marine mammal species that inhabit the southern California Bight. It is also providing direct, controlled, high-resolution measurements of individual reactions to sound, including military sonar systems, to better estimate risk and minimize effects of mid-frequency sonar systems.  Several successful field seasons of SOCAL-BRS have already been completed using an adaptive approach that optimizes the probability of good weather and finding and tagging different focal species.

Click here to view the SOCAL-14 Public Summary   |  Click here to view the SOCAL-14 Final Report


Tagging a blue whale (Photo: J. Calambokidis)

Over 160 tags have been deployed on individuals of nine different species and 75 complete experimental BRS sequences have been conducted on individuals from seven different federally protected marine mammal species (Cuvier’s beaked whale, Baird’s beaked whale, sperm whale, Risso’s dolphin, blue whale, fin whale, and humpback whale). The results of these experiments have been presented in scientific meetings and in the scientific literature (please see numerous papers available at A recent methodological paper summarizes the overall methods in detail: Using accelerometers to determine the calling behavior of tagged baleen whales.

SOCAL-14 will use similar configurations, protocols, focal species, equipment, and areas (based on lessons learned from previous field seasons) with an increasing reliance on smaller, adaptive vessel configurations in certain conditions. SOCAL-14 will also follow on the successful first integration of CEE methods with ongoing regular training operations to increasingly including realistic Navy sonar systems in experimental applications. SOCAL-BRS will continue to attempt to tag whales opportunistically around these activities at much greater distances than typically used in simulated sonar exposures to study the relative effects on behavior of source type, received sound level, and physical range to sound sources.



SOCAL-BRS is a study of basic behavior and responses to controlled sound exposures in a variety of marine mammal species.

Southall Environmental Associates, Inc.

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