Migratory Connectivity of the Chatham Albatross: Assessing Vulnerability to Longline Fishing Throughout Their Migratory Cycle

Abstract

Unremitting population declines of migratory species have led to demands for connectivity knowledge to be more effectively incorporated into management. The Migratory Connectivity in the Oceans system (MiCO) provides an evidence-base of actionable and synthesized knowledge on migratory connectivity to policy arenas. This study contributes to MiCO by providing connectivity knowledge on the Chatham Albatross, Thalassarche eremita, by identifying use areas for the species unique behavior nodes and migratory corridors in the South Pacific Ocean. The Chatham Albatross has a history of longline fishery interaction and has been recorded as bycatch in Peru, Chile, and New Zealand, but few data exist in the high seas. This study assesses Chatham Albatross vulnerability to longline fishing throughout its annual cycle, with a particular interest in the high seas, by performing a spatio-temporal overlap analysis between Chatham Albatross use areas and longline fishing effort. Results reveal that the Chatham Albatross has strong spatial connectivity throughout its post-breeding migratory corridor and strong temporal connectivity throughout its pre-breeding corridor. The greatest potential for seabird-fishery interactions is in August during pre-breeding migration within a core area in the high seas. The identification of this interaction site with longline fisheries provides new information in revisiting Ecologically or Biologically Significant Areas (EBSAs), through describing new areas, and can help strengthen the existing Salas y Gomez and Nazca EBSA.