Since 2008 we have been recording the ambient noise environment during the gray whale breeding season at San Ignacio Lagoon, in collaboration with the Laguna San Ignacio Ecosystem Project (LSIESP) and UABCS. We also have done acoustic tagging research during some years.
The geography of the lagoon allows precise visual counts of the number of animals, making it an excellent location to study whether passive acoustic monitoring can “census” the number of baleen whales in a region (buzzword: “density estimation”). The following paper found that the number of gray whale sounds detected (the ‘S1’ call) increased as the square of the number of animals present:
D. Ponce, A.M. Thode, M. Guerra, J. Urban, S. Swartz, “Relationship between visual counts and call detection rates of gray whales (Eschrichtius robustus) in Laguna San Ignacio, Mexico”, J. Acoust. Soc. Am. 131(4), 2700-2713 (2012).