Passive acoustic monitoring of beaked whale densities in the Gulf of Mexico

TitlePassive acoustic monitoring of beaked whale densities in the Gulf of Mexico
Publication TypeJournal Article
Year of Publication2015
AuthorsHildebrand, John A., Baumann-Pickering Simone, Frasier Kaitlin E., Trickey Jennifer S., Merkens Karlina P., Wiggins Sean M., McDonald Mark A., Garrison Lance P., Harris Danielle, Marques Tiago A., and Thomas Len
JournalScientific Reports
EndNote Rec Number10940

Beaked whales are deep diving elusive animals, difficult to census with conventional visual surveys. Methods are presented for the density estimation of beaked whales, using passive acoustic monitoring data collected at sites in the Gulf of Mexico (GOM) from the period during and following the Deepwater Horizon oil spill (2010–2013). Beaked whale species detected include: Gervais’ (Mesoplodon europaeus), Cuvier’s (Ziphius cavirostris), Blainville’s (Mesoplodon densirostris) and an unknown species of Mesoplodon sp. (designated as Beaked Whale Gulf — BWG). For Gervais’ and Cuvier’s beaked whales, we estimated weekly animal density using two methods, one based on the number of echolocation clicks, and another based on the detection of animal groups during 5 min time-bins. Density estimates derived from these two methods were in good general agreement. At two sites in the western GOM, Gervais’ beaked whales were present throughout the monitoring period, but Cuvier’s beaked whales were present only seasonally, with periods of low density during the summer and higher density in the winter. At an eastern GOM site, both Gervais’ and Cuvier’s beaked whales had a high density throughout the monitoring period.