PYGMY KILLER WHALE (Feresa attenuata): Western North Atlantic Stock

• Main Authors: Stock Definition, Geographic Range
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2007
• Subjects: Killer Whale; North Atlantic; Killer whale
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.174.5058; http://www.nefsc.noaa.gov/publications/tm/tm205/pdfs/64PygmyKillerW.pdf

The pygmy killer whale is distributed worldwide in tropical to sub-tropical waters (Jefferson et al. 1994). Pygmy killer whales are assumed to be part of the cetacean fauna of the tropical western North Atlantic. The paucity of sightings is probably due to a naturally low number of groups compared to other cetacean species. Sightings in the more extensively surveyed northern Gulf of Mexico occur in oceanic waters (Mullin et al. 1994; Mullin and Fulling 2004). Sightings of pygmy killer whales were documented in all seasons during aerial surveys of the northern Gulf of Mexico between 1992 and 1998 (Hansen et al. 1996; Mullin and Hoggard 2000). The western North Atlantic population is provisionally being considered one stock for management purposes. Additional morphological, genetic and/or behavioral data are needed to provide further information on stock delineation. POPULATION SIZE The numbers of pygmy killer whales off the U.S. or Canadian Atlantic coast are unknown, and seasonal abundance estimates are not available for this stock, since it was rarely seen in any surveys. A group of 6 pygmy killer whales was sighted during a 1992 vessel survey of the western North Atlantic off of Cape Hatteras, North Carolina, in waters>1500 m deep (Hansen et al. 1994), but this species was not sighted during subsequent surveys (NMFS 1999; NMFS 2002; Mullin and Fulling 2003). Abundance was not estimated for pygmy killer whales from the 1992 vessel survey because the sighting was not made during line-transect sampling effort; therefore, the