title: Hawksbill turtle terra incognita: conservation genetics of eastern Pacific rookeries.
abstract: Prior to 2008 and the discovery of several important hawksbill turtle (Eretmochelys imbricata) nesting colonies in the EP (Eastern Pacific), the species was considered virtually absent from the region. Research since that time has yielded new insights into EP hawksbills, salient among them being the use of mangrove estuaries for nesting. These recent revelations have raised interest in the genetic characterization of hawksbills in the EP, studies of which have remained lacking to date. Between 2008 and 2014, we collected tissue samples from 269 nesting hawksbills at nine rookeries across the EP and used mitochondrial DNA sequences (766 bp) to generate the first genetic characterization of rookeries in the region. Our results inform genetic diversity, population differentiation, and phylogeography of the species. Hawksbills in the EP demonstrate low genetic diversity: We identified a total of only seven haplotypes across the region, including five new and two previously identified nesting haplotypes (pooled frequencies of 58.4% and 41.6%, respectively), the former only evident in Central American rookeries. Despite low genetic diversity, we found strong stock structure between the four principal rookeries, suggesting the existence of multiple populations and warranting their recognition as distinct management units. Furthermore, haplotypes EiIP106 and EiIP108 are unique to hawksbills that nest in mangrove estuaries, a behavior found only in hawksbills along Pacific Central America. The detected genetic differentiation supports the existence of a novel mangrove estuary "reproductive ecotype" that may warrant additional conservation attention. From a phylogeographic perspective, our research indicates hawksbills colonized the EP via the Indo-Pacific, and do not represent relict populations isolated from the Atlantic by the rising of the Panama Isthmus. Low overall genetic diversity in the EP is likely the combined result of few rookeries, extremely small reproductive populations and evolutionarily recent colonization events. Additional research with larger sample sizes and variable markers will help further genetic understanding of hawksbill turtles in the EP.
authors.affiliation: San Diego State University San Diego California; University of California Davis Davis California; Ocean Associates Incunder contract to the Southwest Fisheries Science Center National Marine Fisheries Service National Oceanic and Atmospheric Administration La Jolla California; Eastern Pacific Hawksbill Initiative San Diego California.
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Gaos
authors.affiliation: San Diego State University San Diego California.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Lewison
authors.affiliation: Texas A&M University College Station Texas; Eastern Pacific Hawksbill Initiative San Diego California.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Liles
authors.affiliation: Fauna & Flora International Managua Nicaragua; Eastern Pacific Hawksbill Initiative San Diego California.
authors.forename: Velkiss
authors.initials: V
authors.lastname: Gadea
authors.affiliation: Fauna & Flora International Managua Nicaragua; Eastern Pacific Hawksbill Initiative San Diego California.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Altamirano
authors.affiliation: Eastern Pacific Hawksbill Initiative San Diego California.
authors.forename: Ana V
authors.initials: AV
authors.lastname: Henríquez
authors.affiliation: Fauna & Flora International Managua Nicaragua; Eastern Pacific Hawksbill Initiative San Diego California.
authors.forename: Perla
authors.initials: P
authors.lastname: Torres
authors.affiliation: Fauna & Flora International Managua Nicaragua; Stanford University Palo Alto California; Eastern Pacific Hawksbill Initiative San Diego California.
authors.forename: José
authors.initials: J
authors.lastname: Urteaga
authors.affiliation: Fundación Equilibrio Azul Quito Ecuador; Eastern Pacific Hawksbill Initiative San Diego California.
authors.forename: Felipe
authors.initials: F
authors.lastname: Vallejo
authors.affiliation: Fundación Equilibrio Azul Quito Ecuador; Eastern Pacific Hawksbill Initiative San Diego California.
authors.forename: Andres
authors.initials: A
authors.lastname: Baquero
authors.affiliation: Fundación Equilibrio Azul Quito Ecuador; Eastern Pacific Hawksbill Initiative San Diego California.
authors.forename: Carolina
authors.initials: C
authors.lastname: LeMarie
authors.affiliation: Fundación Equilibrio Azul Quito Ecuador; Universidad San Francisco de Quito-Galapagos Science Center Isla San Cristobal Ecuador; Eastern Pacific Hawksbill Initiative San Diego California.
authors.forename: Juan Pablo
authors.initials: JP
authors.lastname: Muñoz
authors.affiliation: Universidad San Francisco de Quito-Galapagos Science Center Isla San Cristobal Ecuador.
authors.forename: Jaime A
authors.initials: JA
authors.lastname: Chaves
authors.affiliation: Red Tortuguera, A.C. Guayabitos Nayarit Mexico; Grupo Tortuguero de las Californias, A.C.La Paz Baja California Sur Mexico; Marine Turtle Research Group Cornwall Campus Center for Ecology and Conservation School of Biosciences University of Exeter Cornwall Campus Penryn Cornwall U.K; Eastern Pacific Hawksbill Initiative San Diego California.
authors.forename: Catherine E
authors.initials: CE
authors.lastname: Hart
authors.affiliation: Centro de Protección y Conservación de Tortugas Marinas Playa Teopa Jalisco Mexico; Eastern Pacific Hawksbill Initiative San Diego California.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Peña de Niz
authors.affiliation: Latin American Sea Turtles Tibas San Jose Costa Rica; Eastern Pacific Hawksbill Initiative San Diego California.
authors.forename: Didiher
authors.initials: D
authors.lastname: Chácon
authors.affiliation: Latin American Sea Turtles Tibas San Jose Costa Rica; Eastern Pacific Hawksbill Initiative San Diego California.
authors.forename: Luis
authors.initials: L
authors.lastname: Fonseca
authors.affiliation: Paso Pacifico Managua Nicaragua; Eastern Pacific Hawksbill Initiative San Diego California.
authors.forename: Sarah
authors.initials: S
authors.lastname: Otterstrom
authors.affiliation: Eastern Pacific Hawksbill Initiative San Diego California.
authors.forename: Ingrid L
authors.initials: IL
authors.lastname: Yañez
authors.affiliation: Southwest Fisheries Science Center National Marine Fisheries Service National Oceanic and Atmospheric Administration La Jolla California.
authors.forename: Erin L
authors.initials: EL
authors.lastname: LaCasella
authors.affiliation: Southwest Fisheries Science Center National Marine Fisheries Service National Oceanic and Atmospheric Administration La Jolla California.
authors.forename: Amy
authors.initials: A
authors.lastname: Frey
authors.affiliation: Ocean Associates Inc under contract to the Southwest Fisheries Science Center National Marine Fisheries Service National Oceanic and Atmospheric Administration La Jolla California.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Jensen
authors.affiliation: Southwest Fisheries Science Center National Marine Fisheries Service National Oceanic and Atmospheric Administration La Jolla California.
authors.forename: Peter H
authors.initials: PH
authors.lastname: Dutton
keywords: Critically endangered; Eretmochelys imbricata; management units; mangroves; phylogeography; reproductive ecotype