Southall Environmental Associates, Inc.


SOCAL-12 is the third field season of a multi-year effort (2010-2015), more generally referred to as “SOCAL-BRS” (Behavioral Response Study).  This interdisciplinary research collaboration of private sector, federal agency, and academic scientists is designed to increase knowledge of marine mammal behavior and changes in behavior as a function of sound exposure, including simulated military sonar, for various species.  This project is funded by several research programs of the U.S. Navy and is integrated with related, ongoing field efforts along the U.S. west coast.   It is also part of an international collaboration to measure impacts of human activities on marine mammals using a variety of opportunistic monitoring methods and experimental controlled exposure experiments (CEEs).  The overall objective of these efforts is to understand and thereby better reduce potential negative effects of sounds, including military active sonar systems, on a broad range of marine mammal species.

SOCAL-12 follows two successful field campaigns and will have similar operational configuration, protocols, methodology, focal species, equipment, staff, and operational areas.  Analyses of SOCAL-10 and -11 data are progressing on multiple fronts and the information obtained, operational lessons learned, and consequent expectations based on the two previous field seasons were considered in detail to refine and enhance subsequent field efforts.  Resulting modifications of protocols and priorities for SOCAL-12 were developed in the course of these discussions and are presented here in the plans for the 2012 field season, which is spread over a much larger portion of the year.  Species priorities will shift to a greater emphasis on offshore species such as beaked whales, Risso’s dolphins, and fin whales, when conditions are appropriate; a more targeted approach on blue whales in other specific conditions will augment the existing large dataset on this species.

Two primary phases in July/Aug and October will use the same primary research vessel with contrasting applications of towed passive acoustic capabilities.  Several significant modifications include the use of an even lighter sound source enabling a pilot effort based off San Clemente Island using a small Navy service fast boat.  Additionally, SOCAL-12 will be a transitional year in several ways.  As SOCAL-BRS moves toward the use of real Navy sources in an experimental context in 2013, SOCAL-12 will strategically target operational areas most likely to be utilized in that regard, again within the context of adaptive selection of optimal field conditions.

SOCAL-12 Resources

SOCAL-12 Final Report (pdf)

SOCAL-12 Public Summary (pdf)


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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