False killer whale (Pseudorca crassidens)

The United States Navy’s marine species monitoring program addresses four general topics surrounding the impact of mid-frequency active sonar (MFAS) on protected species: occurrence, exposure, response, and consequences.

The false killer whale (Pseudorca crassidens) is regarded as Data Deficient globally and in Australia. In most parts of its range, there is little information on its social behaviour, dispersal or ecology. The present study is the first assessment of its movement patterns in Australian waters, on the basis of satellite tracking of four individuals, in the Arafura and Timor Seas from late March to early July 2014. When initially tagged, the four individuals occurred in a single group; they then showed generally similar movement patterns and regularly re-associated.

In May 2002, the U.S. Geological Survey and Geological Survey of Canada conducted seismic surveys in the coastal waters of northern Washington and southern British Columbia. As a part of this project, Cascadia Research was contracted by the USGS and GSC to monitor marine mammals from the survey platform J. P. Tully, and provide mitigation on impacts on marine mammals by requesting shutdown of the sound sources when marine mammals were close to the operations.

The current best estimate of population size for false killer whales within Hawaiian waters is only 268 individuals (Barlow 2003), though the estimate is not very precise (CV = 1.08). False killer whales are considered a “strategic” stock by the National Marine Fisheries Service, as “takes” in the Hawai‘i-based swordfish and tuna long-line fishery exceed the “Potential Biological Removal” (PBR) level.