Cephalopods in the potential prey field of sperm whales (Physeter macrocephalus) (Cetacea: Physeteridae) in the northern Gulf of Mexico

Abstract

Cephalopods of the northern Gulf of Mexico are widely distributed and provide an important food source for a variety of marine animals. Sperm whales are year-round residents in the northern Gulf of Mexico. Prey availability has been proposed as an explanation for this non-migratory whale population. To examine this explanation, a short pilot cruise was conducted during the summer of 2009 to test equipment and to obtain preliminary observations. Then the 3-month Sperm Whale Acoustic Prey Study (SWAPS) was conducted during the winter/spring of 2010 to sample the mid-water pelagic community for possible prey of sperm whales. It also compared sperm whale distribution and prey composition across habitats of the northern Gulf of Mexico. This paper focuses on the cephalopod diversity within the mid-water pelagic community and assesses potential prey of the endangered sperm whales.

Keywords:

• cephalopod
• Gulf of Mexico
• sperm whale
• diversity
• predator/prey

Acknowledgements

The authors would like to acknowledge the NOAA ship Pisces crew and surveying team for their time during both the 2009 and the 2010 cruises. The authors also acknowledge the support staff at the Museum Support Center for their assistance while species verification was being completed. Lastly, the authors would like to acknowledge Tobias Jedlund for his assistance in preparation of figures for publication.