Marine Mammal Studies at the Southern California Offshore Range (SCORE)

Cuvier’s beaked whales on a very calm day at SCORE.  Photo by Erin Falcone, 2007

Cascadia began working with scientists from the Naval Undersea Warfare Center (NUWC) and Scripps Institution of Oceanography (SIO) on a collaborative visual-acoustic study of marine mammals at SCORE, a naval training area off the coast of southern California, in August 2006. Since that time we have participated in two surveys each year, ranging in length from 5-10 days.

During these surveys, a team of acoustic observers at the Range Operations Center, North Island, San Diego uses the broad array of bottom-mounted hydrophones on the west side of San Clemente Island (SOAR) to detect and localize vocalizing marine mammals. They then communicate this information to the boats so that they may approach the animals to confirm their species and to collect data, photographs, tissue samples, and additional focused recordings. As we have become increasingly successful at finding animals on the range, we expanded our effort in 2008 to include satellite tag deployments on select species so that we may remotely monitor the movements of individuals for periods up to several months.

Although we are interested in all species encountered, we are particularly focused on beaked whales in this area due to their sensitivity to underwater sound sources in other parts of the world. Understanding how these animals use the west side of San Clemente Island, where naval sound sources are regularly employed during training, may greatly facilitate our understanding of the relationship between beaked whales and sound so that the navy may more successfully mitigate the effects in the future. During our October 2007 survey we observed and identified an unusually high number of Cuvier’s beaked whales on the range in a five-day period, and collected a considerable amount of data on short-term movement, dive cycles, and group composition.  An article summarizing our work with this species at SCORE through 2008 is available here.

Since that time, we have continued to have productive encounters with Cuvier’s beaked whales during periods of calm winds, including two satellite tag deployments.  We have also deployed tags on fin whales, Risso’s dolphins, and bottlenose dolphins, all of which are providing the first insights into habitat use and movements for these species in the Southern California Bight.  Plans are underway to compare the movements of animals to coincident sonar use during naval exercises.

This study is also developing the first regional photo-ID studies of Cuvier’s beaked whales and fin whales, and is contributing photos of bottlenose and Risso’s dolphins to collaborators at SIO and Southwest Fisheries Science Center for assessments of these species.

Additional links to supplementary materials…

Summary of October 2007 test

Summary of August and October 2008 tests

Summary of July 2009 test

For more information on this project write to: efalcone (at)

Updated August 2009.

Photographs on this page (c) Cascadia Research, use only with permission