Opportunities for tracking and observing marine mammals were coordinated with Navy training operations during the fourth year of this research project. This enabled the first-ever use of full-scale operational Navy midfrequency active (MFA) sonar systems in the context of a controlled experimental context while taking careful precautions to avoid harming marine mammals. Four distinct operational phases were conducted this year during which 14 specials of marine mammals were observed, photographed and tracked. 41 animals from 5 different species were tagged, including Cuvier’s beaked whales, fin whales, Risso’s dolphins, and a North Pacific minke whale. Download the full report, Biological and Behavioral Response Studies of Marine Mammals in Southern California, 2013 (“SOCAL‐13”) – Final Project Report (20 April 2014) or the SOCAL 13 project overview and objectives.