Fish vertical distribution and marine mammal co-occurrence off Cape Hatteras, NC

• Main Authors: Aber, Rachael, Horne, John K.
• Format: Text
• Language: unknown
• Published: Pilot Scholars 2018
• Subjects: Environmental Studies; Marine Biology; toothed whale
• Online Access: https://pilotscholars.up.edu/env_studpubs/3; https://pilotscholars.up.edu/cgi/viewcontent.cgi?article=1002&context=env_studpubs

Mesopelagic (mid-water) fish are important components of toothed whale (Odontocete) diets. Few studies have simultaneous measurements of predator occurrence and potential prey density distributions over long durations. Echoshounder and hydrophone measurements were used to characterize vertical distributions of potential prey and relative abundance of 7 marine mammal groups in the water column off Cape Hatteras, NC. Co-occurrence of the two groups was used as an index of predator-prey interaction. There were fewer than expected (2/7 daily resolution; 1/7 6-hourly resolution) significant correlations between the number of marine mammal occurrences and the potential prey field density. There were no significant distributional correlations when there were significant density correlations. At both resolutions, Cuvier’s and Gervais’ beaked whales and Sperm whales were correlated with salinity and/or water temperature. Further research is necessary to determine whether metrics of prey field density influence the occurrence and potential foraging of Odontocete marine mammals.