Cross-seasonal foraging site fidelity of subantarctic fur seals: implications for marine conservation areas

Marine top-predators show fidelity to foraging areas with predictable high-quality food patches. of predictable prey yield are of conservation importance and telemetry data aid in such areas. This study examined colony specific and intra-individual foraging site of lactating Subantarctic fur seals (Arctocephalus tropicalis) from Marion Island (46°54‟S, 37°45‟E) during summer and winter, comparing commitment to foraging areas across . Thirty-one females were tracked in 2009-2013 resulting in 111 foraging trips for . Inter-annually, preferred foraging areas in summer were consistently ≈200 km due east Marion Island towards the Gallieni Rise. Summer individuals' core utilization areas by an estimated 32.84% (CI: 24.53% - 41.94%). Seals responded to a decrease in productivity in winter by foraging in more distant alternative areas. In winter, changed their travelling direction to north-east of Marion Island and foraged further , around the Del Caño Rise and along the South-west Indian Ridge. Despite preferring foraging areas in winter, there was a low amount of overlap 6.03% (CI 4.02% - 9.16%) of core utilization areas. The foraging grounds identified in this study have not been in prior conservation assessments and are important in conserving for this globally significant, and currently declining, population of Subantarctic fur seals and perhaps other toppredators at Marion Island as well. Differences between winter and summer preferred areas highlight the importance of sampling during different seasons when using data for the identification of potential pelagic conservation areas.