Foraging habitats of top predators, and Areas of Ecological Significance, on the Kerguelen Plateau

• Main Authors: Hindell, MA, Lea, MA, Bost, CA, Charrassin, JB, Gales, N, Goldsworthy, S, Page, B, Robertson, G, Wienecke, B, O'Toole, M, Guinet, C
• Format: Book Part
• Language: English
• Published: Societe Francaise d'Ichtyologie 2011
• Subjects: Biological Sciences; Ecology; Marine and Estuarine Ecology (incl. Marine Ichthyology); Antarctic; Heard Island; Kerguelen; Kerguelen Islands; Antarc*; Antarctic Fur Seals; Elephant Seals; King Penguins; Southern Elephant Seals
• Online Access: http://cths.fr/an/societe.php?id=1431; http://ecite.utas.edu.au/76856

AbstrAct. - Avian and mammalian predators play a key role in the Kerguelen Plateau ecosystem, both with respect tostructuring the marine community and its response to anthropogenic influences, such as climate change and commercialfisheries. A powerful way to determine regions of particular ecological importance is to identify Areas of EcologicalSignificance (AES): regions that are utilized by multiple predator species. Such concentrations of foraging activity areindicative of enhanced primary and/or secondary productivity. These are regions that require specialised managementefforts, and which are of considerable importance in the development of ecological models and climate monitoring systems.This study integrates tracking and diving data from a suite of predator species collected as part of both the French andAustralian Antarctic programs at Kerguelen Islands and Heard Island respectively. Tracking and/or dive data for Macaroniand King penguins, southern Elephant seals, Antarctic fur seals and Black-browed albatross were analysed. The estimatedpath for each animal was derived using state-space models, which also allocated each location to either transit or searchbehavioural modes. For diving species, dive depth data were temporally allocated along the path, providing information onthree-dimensional habitat use. Areas of Ecological Significance for each species and for the combined suite of predatorswere identified using Kernel Density analysis. The role of bathymetry, ocean circulation and other environmental factorsunderlying the AES were established using deterministic models, which can be used to predict predator foraging habitatsacross the entire plateau.