Monster Seminar JAM - Satellite tracking of Black-footed Albatross (Phoebastria nigripes): Oceanographic and Conservation Implications
Dr. K. David Hyrenbach, Duke University
Satellite tracking has opened a window into the poorly understood habits and habitats of oceanic seabirds, both during the breeding season and the post-breeding dispersal period. The Black-footed Albatross (Phoebastria nigripes), an endangered species according to IUCN criteria, is susceptible to bycatch in pelagic and demersal longline fisheries across the North Pacific Ocean. Although large population declines have been projected using fishing effort and bycatch estimates, little is known about the movements and threats faced by individual albatross at-sea, especially during their post-breeding dispersal. This presentation summarizes the results of past tagging studies (in collaboration with colleagues from the Claremont Colleges, Oikonos - Ecosystem Research, Moss Landing Marine Labs, NOAA, USGS, and Wake Forest University), presents currently ongoing efforts, and discusses future research venues.
In 1998, we used ARGOS satellite-linked transmitters to investigate the foraging ranges, habitat-use, and overlap of breeding albatross (January - June) nesting in Tern Island (NW Hawaiian Islands). Analyses of telemetry data in conjunction with satellite-derived sea surface temperature (AVHRR) and chlorophyll a concentration (SeaWiFS) suggest that breeding albatross habitat selection is scale-dependent. Over macro-mega scales (1000's km) albatross dispersion is influenced by water mass distributions and constrained by breeding duties at the colony. During the brooding period (< 19 days after chicks hatched), black-footed albatross restricted their movements to tropical waters (> 20 deg C). The foraging ranges expanded during the rearing period (19 - 140 days post-hatching), when the birds commuted to the California Current, and visited U.S. National Marine Sanctuaries off central California. Within these large-scale water masses, albatross focused their foraging activities within smaller coarse-meso scale (10's - 100's km) features. Foraging birds engaged in area-restricted searching behavior along continental shelf / slope regions (California British Columbia, Aleutians). Conversely, the satellite-tracked albatross commuted rapidly over tropical and subtropical waters between highly-productive foraging areas and their colony.
In 2004, we started tagging post-breeding birds captured at sea within the Cordell Bank National Marine Sanctuary. These deployments have revealed far-ranging summer / fall movements (July - October), spanning the fishing grounds of U.S. and foreign pelagic longline fleets. All the birds tagged thus far have ventured outside of the U.S. EEZ, with one reaching Hokkaido (Japan), >7,300 km from the tagging site. Quantifying the movements and habitats of endangered albatross is essential to identify those fisheries and countries with responsibility for their conservation, and to determine whether zoning strategies can help protect these far-ranging seabirds. This research highlights the critical importance of incorporating an understanding of the natural history and the oceanographic habitats of protected species into management strategies.
Date and Time:
March 2, 2006,
11:00 am - 12:30 pm