Functional responses of penguins: building towards better monitoring indices for adaptive management of the Antarctic krill fishery

A key aim in managing the harvest of Antarctic krill is to ensure the long-term sustainability of the fishery and the marine ecosystem, including krill-dependent predators such as seals, penguins and whales. If predators are to be used as indicators in the management of marine ecosystems (e.g., CCAMLR Ecosystem Monitoring Program; CEMP), the functional responses between predators and prey (i.e., the relationships between predators foraging rate and prey abundance) is a critical. Current CEMP predator response variables, however, show variable relationships with estimates of krill abundance and those associated with monitoring foraging behaviour makes poor use of modern telemetry technology. Our primary objective is to develop monitoring indices that can quantify and characterize functional responses of penguins to changes in their prey field, as a precursor to developing additional CEMP monitoring parameters that will improve ecosystem-based Feedback Management (FBM). Here we present exploratory analyses of chinstrap penguins Pygoscelis antarctica foraging behaviour at two sites in the Bransfield Strait (Deception Island, Kopaitic Island) as a first step towards developing alternate monitoring indices of the functional relationships between predator foraging behaviour and prey abundance.