Passive Acoustic Monitoring for Marine Mammals in the SOCAL Range Complex June 2015 – April 2016

About

Passive acoustic monitoring was conducted in the Navy’s Southern California Range Complex from June 2015 to April 2016 to detect marine mammal and anthropogenic sounds. High-frequency Acoustic Recording Packages (HARPs) recorded sounds between 10 Hz and 100 kHz at three locations: west of San Clemente Island (1,000 m depth, site H), southwest of San Clemente Island (1200 m depth, site N), and west of La Jolla, California (500 m depth, site P). Data analysis was performed using automated computer algorithms. Calls of two baleen whale species were detected: blue whale B calls and fin whale 20 Hz calls. Both species were present at all sites, but at site H blue whale B calls were most common and the fin whale acoustic index representative of 20 Hz calls was highest. Blue whale B calls were least common at site P while the fin whale acoustic index was lowest at site N. Blue whale B call detections peaked from August to November 2015 and very few