Use of marine sanctuaries by far-ranging predators: commuting flights to the California Current System by breeding Hawaiian albatrosses




Quantifying the dispersion and habitats of far-ranging seabirds, turtles, and cetaceans is essential to assess whether zoning strategies can help protect upper-trophic marine predators. In this paper, we focus on Black-footed Albatross (Phoebastria nigripes) use of three US national marine sanctuaries off central California: Cordell Bank, Gulf of the Farallones, and Monterey Bay. We assessed the significance of these protected areas to albatrosses by: (i) documenting commuting flights between Hawaiian breeding sites and the California Current System (CCS); (ii) quantifying albatross dispersion patterns on the central California continental shelf and slope, and (iii) characterizing albatross habitats within sanctuary waters using concurrent satellite-tracking data and vessel-based sightings. Chick-rearing albatrosses commuted from their colony on Tern Island, Hawaii (23.878°N, 166.288°W), to the CCS (34–48°N) and two of the eight satellite-tracked birds entered the marine sanctuaries. Among the telemetry locations within sanctuary waters, two-thirds (24 of 36) straddled the shelf break and slope (201–2000-m depth), a pattern underscored by a concurrent vessel-based survey in which 144 Black-footed Albatrosses were sighted. This study illustrates the value of coordinated satellite telemetry and vessel-based surveys to assess the distributions of protected species within existing marine protected areas. More specifically, our results underscore the importance of three central California marine sanctuaries to Hawaiian albatrosses breeding in subtropical waters, approximately 4500 km away.