Abstract:
Humpback whales (Megaptera novaeangliae) are showing strong recovery from commercial whaling in the western South Atlantic. In this region, humpback whales migrate annually from their winter breeding grounds off the coast of Brazil to their summer feeding grounds near to the Polar Front, an area that includes the waters of South Georgia and the South Sandwich Islands (SGSSI). This latter region includes a Marine Protected Area (MPA), which has been developed to ensure sustainable management of fisheries, and protection of foraging predators. To date, management measures within the MPA have primarily been concerned with foraging predators that rely upon Antarctic krill, including for a number of previously over-exploited species. With humpback whales increasing in the western South Atlantic, understandingnderstanding their spatiotemporal distribution within the MPA is important as it will help inform management particularly in respect of interactions between humpback whales and the regional fishery for Antarctic krill. Here we develop habitat models from the distribution and movement patterns of 16 individuals at their high-latitude feeding grounds, south of 50°S. We show that whale habitat use varies throughout the foraging period. Upon reaching their feeding ground, whales use the area to the east of the South Sandwich Islands, moving westward into the centre of the Scotia Arc and towards South Georgia during the high summer, and then expanding back towards the east in the winter. Based on these findings, we discuss the implications for the future, including necessary research required for underpinning management.
