title: Modeling Nonresident Seabird Foraging Distributions to Inform Ocean Zoning in Central California.
abstract: Seabird aggregations at sea have been shown to be associated with concentrations of prey. Previous research identified Central California as a highly used foraging area for seabirds, with locally breeding seabirds foraging close to their colonies on Southeast Farallon Island. Herein, we focus on nonresident (i.e. non-locally breeding) seabird species off of Central California. We hypothesized that high-use foraging areas for nonresident seabirds would be influenced by oceanographic and bathymetric factors and that spatial and temporal distributions would be similar within planktivorous and generalist foraging guilds but would differ between them. With data collected by the Applied California Current Ecosystem Studies (ACCESS) partnership during cruises between April and October from 2004-2013, we developed generalized linear models to identify high-use foraging areas for each of six nonresident seabird species. The four generalist species are Phoebastria nigripes (black-footed albatross), Ardenna griseus (sooty shearwater), Ardenna creatopus (pink-footed shearwater), and Fulmarus glacialis (northern fulmar). The two planktivorous species are Phalaropus lobatus (red-necked phalarope) and Phalaropus fulicarius (red phalarope). Sea surface temperature was significant for generalist species and sea surface salinity was important for planktivorous species. The distance to the 200-m isobath was significant in five of six models, Pacific Decadal Oscillation with a 3-month lag in four models, and sea surface fluorescence, the distance to Cordell Bank, and depth in three models. We did not find statistically significant differences between distributions of individual seabird species within a foraging guild or between guilds, with the exception of the sooty shearwater. Model results for a multi-use seabird foraging area highlighted the continental shelf break, particularly within the vicinity of Cordell Bank, as the highest use areas as did Marxan prioritization. Our research methods can be implemented elsewhere to identify critical habitat that needs protection as human development pressures continue to expand to the ocean.
authors.affiliation: Romberg Tiburon Center for Environmental Studies, San Francisco State University, Tiburon, CA, United States of America.|Department of Geography and Environment, San Francisco State University, San Francisco, CA, United States of America.|Point Blue Conservation Science, Petaluma, CA, United States of America.
authors.forename: Anna J
authors.identifier: http://orcid.org/0000-0002-8450-6855
authors.initials: AJ
authors.lastname: Studwell
authors.affiliation: Romberg Tiburon Center for Environmental Studies, San Francisco State University, Tiburon, CA, United States of America.|Department of Geography and Environment, San Francisco State University, San Francisco, CA, United States of America.
authors.forename: Ellen
authors.initials: E
authors.lastname: Hines
authors.affiliation: Point Blue Conservation Science, Petaluma, CA, United States of America.
authors.forename: Meredith L
authors.initials: ML
authors.lastname: Elliott
authors.affiliation: Point Blue Conservation Science, Petaluma, CA, United States of America.
authors.forename: Julie
authors.initials: J
authors.lastname: Howar
authors.affiliation: Department of Geography and Environment, San Francisco State University, San Francisco, CA, United States of America.
authors.forename: Barbara
authors.initials: B
authors.lastname: Holzman
authors.affiliation: Point Blue Conservation Science, Petaluma, CA, United States of America.
authors.forename: Nadav
authors.initials: N
authors.lastname: Nur
authors.affiliation: Point Blue Conservation Science, Petaluma, CA, United States of America.
authors.forename: Jaime
authors.initials: J
authors.lastname: Jahncke
mesh_terms: D000818:Animals; D001070:Appetitive Behavior / Q000502:physiology*; D001717:Birds; D002140:California; D003247:Conservation of Natural Resources / Q000379:methods*; D017753:Ecosystem; D005247:Feeding Behavior / Q000502:physiology*; D008962:Models, Theoretical; D009792:Oceans and Seas