Long-beaked common dolphin (Delphinus capensis)

From 4 to 17 June 1999, the U.S. Geological Survey conducted seismic surveys in the coastal waters of the Pacific Ocean, between Los Angeles and San Diego, to investigate earthquake hazards. As a part of this project, Cascadia Research was contracted by the USGS to monitor marine mammals from the survey platform and provide mitigation on impacts on marine mammals by requesting shutdown of the sound sources when marine mammals were close to the operations.

From 14 to 28 June 2002, the U.S. Geological Survey conducted seismic-reflection surveys in the Santa Barbara Channel area off of southern California. As a part of this project, Cascadia Research was contracted by the USGS to monitor marine mammals from the survey platform and provide mitigation on impacts on marine mammals by requesting shutdown of the sound sources when marine mammals were close to the operations.

Opportunistic observations of behavioral responses by delphinids to incidental mid-frequency active (MFA) sonar were recorded in the Southern California Bight from 2004 through 2008 using visual focal follows, static hydrophones, and autonomous recorders. Sound pressure levels were calculated between 2 and 8 kHz. Surface behavioral responses were observed in 26 groups from at least three species of 46 groups out of five species encountered during MFA sonar incidents.

Blue whales occur widely in the world’s ocean and became a target of commercial whalers in what is termed the modern era of whaling. Largest populations occurred in the southern Hemisphere and the Antarctic blue whale was the most heavily hit by commercial whaling with close to 300,000 killed primarily in the first half of the 20th century. From a world-wide abundance of over 300,0000 their numbers are estimated at close to 10,000 now, more than 40 years after the supposed end of commercial whaling in 1966.