From clicks to counts: Using passive acoustic monitoring to estimate the density and abundance of Cuvier’s beaked whales in the Gulf of Alaska

About

A visual and acoustic line-transect survey of marine mammals was conducted in the central Gulf of Alaska (GoA) during the summer of 2013. The survey area was divided into four sub-strata to reflect four distinct habitats; ‘inshore’, ‘slope’, ‘offshore’ and ‘seamount’. Passive acoustic monitoring was conducted using a towed-hydrophone array system. One of the main objectives of the acoustic survey was to obtain an acoustic-based density estimate for beaked whales. Three species of beaked whales were identified; Cuvier’s (Ziphius cavirostris), Baird’s (Berardius bairdii) and Steijneger’s (Mesoplodon stejnegeri).