CHARACTERIZATION OF WESTERN NORTH ATLANTIC RIGHT WHALE SPRING FEEDING HABITAT

• Main Authors: R Haebler, R Kenney, R Comeleo
• Format: Text
• Language: unknown
• Published: 2005
• Subjects: North Atlantic; North Atlantic right whale
• Online Access: http://oaspub.epa.gov/eims/eimsapi.dispdetail?deid=80269

The Great South Channel region of the southwestern Gulf of Maine, between George's Bank and Cape Cod, is the primary spring feeding ground for the western North Atlantic population of the I northern right whale, E. glacialis .Since this whale is so endangered, it is critical to improve our understanding of what characteristics of this area allow for the production of this food resource. The primary objective of this study was to characterize suitable feeding habitat for right whales in the Great South Channel region by describing the spatial relationships between whale sighting locations, prominent bathymetric features, and sea surface thermal structure, using easily-obtained, remotely-sensed data. The second goal of the project was to apply the habitat suitability "template" developed for the Great South Channel region to other areas of the western North Atlantic ocean to identify potential right whale feeding habitats. Right whale feeding habitat in the Great South Channel region was characterized in terms of five different physical habitat factors. Three factors are related to sea-floor topography: (1) water depth, (2) sea-floor slope, and (3) sea-floor aspect and two are related to sea surface thermal structure: (4) surface temperature and (5) surface temperature gradient. A GIS (ARC/INFO) was used to overlay sighting locations of right whales in the Great South Channel on digital, grided maps of each of the five habitat factors. A simple, GIS-based, spatial model was developed which allows users to locate suitable feeding habitat by identifying areas of spatial coincidence (overlay) of the five different habitat factors. Habitat was classified as "highly suitable" where all five habitat factors were in the optimum range and as "moderately suitable" where all five habitat factors were in the acceptable range. The final habitat suitability maps identify areas where suitable sea-floor topography and sea surface thermal structure overlay to create physical conditions required for high-density patches of zooplankton. As the sea surface warms through the late spring and early summer, suitable habitat areas shift to the northeast, tracking a band of suitable sea surface temperature.