title: Active dispersal in loggerhead sea turtles (Caretta caretta) during the 'lost years'.
abstract: Highly migratory marine species can travel long distances and across entire ocean basins to reach foraging and breeding grounds, yet gaps persist in our knowledge of oceanic dispersal and habitat use. This is especially true for sea turtles, whose complex life history and lengthy pelagic stage present unique conservation challenges. Few studies have explored how these young at-sea turtles navigate their environment, but advancements in satellite technology and numerical models have shown that active and passive movements are used in relation to open ocean features. Here, we provide the first study, to the best of our knowledge, to simultaneously combine a high-resolution physical forcing ocean circulation model with long-term multi-year tracking data of young, trans-oceanic North Pacific loggerhead sea turtles during their 'lost years' at sea. From 2010 to 2014, we compare simulated trajectories of passive transport with empirical data of 1-3 year old turtles released off Japan (29.7-37.5 straight carapace length cm). After several years, the at-sea distribution of simulated current-driven trajectories significantly differed from that of the observed turtle tracks. These results underscore current theories on active dispersal by young oceanic-stage sea turtles and give further weight to hypotheses of juvenile foraging strategies for this species. Such information can also provide critical geographical information for spatially explicit conservation approaches to this endangered population.
authors.affiliation: Biology, Stanford University, Hopkins Marine Station, 120 Oceanview Boulevard, Pacific Grove, CA 93950, USA dbriscoe@stanford.edu.
authors.forename: D K
authors.initials: DK
authors.lastname: Briscoe
authors.affiliation: Joint Institute for Marine and Atmospheric Research, National Oceanic and Atmospheric Administration, 2032 Southeast Oregon State University Drive, Newport, OR 97365, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Parker
authors.affiliation: Pacific Islands Fisheries Science Center, National Oceanic and Atmospheric Administration Inouye Regional Center, National Marine Fisheries Service, 1845 WASP Boulevard Building 176, Honolulu, HI 96818, USA.
authors.forename: G H
authors.initials: GH
authors.lastname: Balazs
authors.affiliation: Port of Nagoya Public Aquarium, Minato-ku, Nagoya 455-0033, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kurita
authors.affiliation: Usa Marine Biological Institute, Kochi University, Usa Tosa, Kochi 781-1164, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Saito
authors.affiliation: Port of Nagoya Public Aquarium, Minato-ku, Nagoya 455-0033, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Okamoto
authors.affiliation: Hawaii Preparatory Academy, 65-1692 Kohala Mountain Road, Kamuela, HI 96743, USA.
authors.forename: M
authors.initials: M
authors.lastname: Rice
authors.affiliation: Port of Nagoya Public Aquarium, Minato-ku, Nagoya 455-0033, Japan.
authors.forename: J J
authors.initials: JJ
authors.lastname: Polovina
authors.affiliation: Biology, Stanford University, Hopkins Marine Station, 120 Oceanview Boulevard, Pacific Grove, CA 93950, USA Center for Ocean Solutions, Stanford University, 99 Pacific Street, Suite 555E, Monterey, CA 93949, USA.
authors.forename: L B
authors.initials: LB
authors.lastname: Crowder
mesh_terms: D063147:Animal Distribution; D060105:Animal Shells; D000818:Animals; D004463:Ecology / Q000379:methods; D017753:Ecosystem; D007564:Japan; D009792:Oceans and Seas; D014426:Turtles / Q000502:physiology*
keywords: distribution; foraging; loggerhead sea turtle; migration; ocean circulation model