Marine mammals of the Pacific with particular reference to the production of underwater sound

Abstract

The present report is concerned with one of the oceanic biology subjects designated by the Navy for investigation. In compliance with the assignment the objective has been (1) to assemble, analyze and where possible correlate with environmental factors, available information from Pacific waters, and (2) upon completion of this work to prepare recommendations for further field research designed to fulfill Navy requirements. A proposed program will be presented in a separate report.

Considerable interference encountered by underwater acoustic gear is now known to be of biological origin. In coastal areas, especially along coral and rocky shores, much background noise can be attributed to fish (Fish, 1948) and invertebrates (Johnson et al., 1947). But beyond the influence of land there are certain characteristic sounds which have repeatedly been associated with marine mammals. Numerous visual observations of whales and porpoises coincident with the reception of such sounds have been made, and the charting of Submarine Patrol records (Charts VII to X, pages 56 to 59) reveals that all similar unidentified contacts have occurred within the known seasonal and geographical range of common marine mammals.