Eastern Pacific Hawksbill Initiative

San Salvador, El Salvador

Eastern Pacific Hawksbill Initiative

San Salvador, El Salvador
Time filter
Source Type

Gaos A.R.,San Diego State University | Gaos A.R.,University of California at Davis | Gaos A.R.,National Oceanic and Atmospheric Administration | Lewison R.L.,San Diego State University | And 24 more authors.
Ecology and Evolution | Year: 2016

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. © 2016 Published by John Wiley & Sons Ltd.

Gaos A.R.,San Diego State University | Gaos A.R.,University of California at Davis | Lewison R.R.,San Diego State University | Wallace B.P.,Eastern Pacific Hawksbill Initiative | And 9 more authors.
Journal of Experimental Marine Biology and Ecology | Year: 2012

Understanding the movement and dive behaviour of marine turtles directly informs spatial management strategies. Hawksbill turtles (Eretmochelys imbricata, Linnaeus 1766) are a globally endangered marine turtle species, with populations in the eastern Pacific Ocean identified as particularly threatened. To date, very little research on the dive behaviour of hawksbills has been conducted. Most studies have focused on juveniles in the Wider Caribbean region, and no dive behaviour has been described for hawksbills in the eastern Pacific. Using satellite-relayed dive loggers attached to five adult hawksbills, we analyzed dive trends and differences among individuals, movement phases and diel time periods, and compared our findings with those from hawksbills in other regions of the world. Our research indicates that adult hawksbills in the eastern Pacific predominantly use shallow waters (i.e. ≤ 10 m), with dives rarely occurring to depths > 20. m. Additionally, in contrast to previous research, we found similar dive behaviour across diel time periods, suggesting nocturnal activity may be more prevalent than previously believed. Despite some similarities in dive behaviour across individuals, individual variability was also evident. More research on adult hawksbills is urgently needed to increase our understanding of basic hawksbill ecology and behaviour, and improve management of this critically endangered species in the eastern Pacific Ocean. © 2012 Elsevier B.V.

Gaos A.R.,Eastern Pacific Hawksbill Initiative | Gaos A.R.,San Diego State University | Gaos A.R.,University of California at Davis | Lewison R.L.,San Diego State University | And 16 more authors.
Marine Ecology Progress Series | Year: 2012

Elucidating spatio-temporal movements of animals is an integral component of wildlife conservation and protected species management. Between 2008 and 2010 we satellite tracked 15 adult female hawksbill turtles Eretmochelys imbricata in the eastern Pacific Ocean to evaluate their movement behavior and to guide management and conservation efforts of this highly endangered population. Movements and habitat use were highly neritic, and post-nesting migration distances (maximum = 283.11 km) were short relative to migrations of other sea turtle species. In foraging areas, the majority of hawksbills established restricted, inshore home ranges within mangrove estuaries. A large proportion (>65%) of turtle location points fell within protected areas, although many of these sites lack enforcement and monitoring. The consistent use of estuar-ine and mangrove habitat for nesting and foraging may explain why hawksbills went virtually undetected in the eastern Pacific for decades. The spatially restricted and neritic life cycles of adult hawksbills in the eastern Pacific highlight threats (e.g. overlap with coastal fisheries, increased susceptibility to habitat degradation and/or catastrophic events) and opportunities for conservation (e.g. acute conservation target areas, less variant jurisdictional boundaries/regulations) for this species. Our results underscore the importance of strengthening protected area management, mangrove estuary protection and hawksbill research and conservation in the eastern Pacific. © Inter-Research 2012.

Liles M.J.,Texas A&M University | Peterson M.J.,Texas A&M University | Seminoff J.A.,National Oceanic and Atmospheric Administration | Altamirano E.,Fauna and Flora International | And 10 more authors.
Biological Conservation | Year: 2015

Conservation biologists frequently use data from the same or related species collected in diverse geographic locations to guide interventions in situations where its applicability is uncertain. There are dangers inherent to this approach. The nesting habitats of critically endangered hawksbill sea turtles (Eretmochelys imbricata) cover a broad geographic global range. Based on data collected in the Caribbean and Indo-Pacific, conservationists assume hawksbills prefer open-coast beaches near coral reefs for nesting, and that individual hawksbills are highly consistent in nest placement, suggesting genetic factors partially account for variation in nest-site choice. We characterized nest-site preferences of hawksbills in El Salvador and Nicaragua, where >80% of nesting activity occurs for this species in the eastern Pacific, and ~90% of hawksbill clutches are relocated to hatcheries for protection. We found hawksbills preferred nest sites with abundant vegetation on dynamic beaches within mangrove estuaries. Nests in El Salvador were located closer to the ocean and to the woody vegetation border than nests in Nicaragua, suggesting female hawksbills exhibit local adaptations to differences in nesting habitat. Individual hawksbills consistently placed nests under high percentages of overstory vegetation, but were not consistent in nest placement related to woody vegetation borders. We suggest conservation biologists use caution when generalizing about endangered species that invest in specific life-history strategies (e.g., nesting) over broad ranges based on data collected in distant locations when addressing conservation issues. © 2015 Elsevier Ltd.

Gaos A.R.,San Diego State University | Lewison R.L.,San Diego State University | Yanez I.L.,Eastern Pacific Hawksbill Initiative | Wallace B.P.,Wildlife Conservation Society | And 10 more authors.
Biology Letters | Year: 2012

Adult hawksbill turtles (Eretmochelys imbricata) are typically described as open-coast, coral reef and hard substrate dwellers. Here, we report new satellite tracking data on female hawksbills from several countries in the eastern Pacific that revealed previously undocumented behaviour for adults of the species. In contrast to patterns of habitat use exhibited by their Caribbean and Indo-Pacific counterparts, eastern Pacific hawksbills generally occupied inshore estuaries, wherein they had strong associations with mangrove saltwater forests. The use of inshore habitats and affinities with mangrove saltwater forests presents a previously unknown life-history paradigm for adult hawksbill turtles and suggests a potentially unique evolutionary trajectory for the species. Our findings highlight the variability in life-history strategies that marine turtles and other wide-ranging marine wildlife may exhibit among ocean regions, and the importance of understanding such disparities from an ecological and management perspective. © 2011 The Royal Society.

Liles M.J.,Texas A&M University | Peterson M.J.,Texas A&M University | Lincoln Y.S.,Texas A&M University | Seminoff J.A.,National Oceanic and Atmospheric Administration | And 3 more authors.
Local Environment | Year: 2015

Hawksbill turtles (Eretmochelys imbricata) are highly endangered in the eastern Pacific Ocean, yet their eggs continue to be an important subsistence resource for impoverished coastal residents in El Salvador. In this study, we use naturalistic inquiry to explain the realities experienced by coastal residents who share habitat with hawksbills in El Salvador, and then suggest implications of the disparities between these realities and international priorities for hawksbill conservation and community development in El Salvador and other low-income regions. To provide a context for understanding hawksbill conservation and its implications for similar challenges related to conservation and wellbeing, we first summarise the conservation context, including the emergence of sea turtle conservation in El Salvador. We then describe our naturalistic approach, including the ethnographic methodology for this study. Finally, we detail the analysis of interviews conducted with tortugueros (i.e. local sea turtle egg collectors), to help explain how hawksbills fit into local realities. Our results demonstrate that, from the perspective of tortugueros, (1) the primary importance of hawksbills is the economic value attached to egg sales, but there exists a deeper connection to local culture; (2) egg purchase by hatcheries is a socially just conservation strategy that benefits both hawksbill and human wellbeing; and (3) opportunities for local residents to participate in decision-making regarding sea turtle conservation are limited, and should be increased. We argue that harmonising international conservation priorities with local community development realities is one path towards simultaneously contributing to long-term sea turtle recovery and human wellbeing in low-income regions. © 2014 Taylor & Francis.

Wetterer J.K.,Florida Atlantic University | Liles M.J.,Eastern Pacific Hawksbill Initiative | Liles M.J.,Texas A&M University | Sermeno J.M.,University of El Salvador | And 9 more authors.
Florida Entomologist | Year: 2016

As in many other parts of the world, in El Salvador, few sea turtle (Testudines: Cheloniidae) eggs develop and hatch in situ on nesting beaches. Instead, conservationists relocate most sea turtle eggs to hatcheries for protection. Hatchery managers incubate the eggs in artificial nests within protected enclosures and then release the hatchling sea turtles into the ocean. We surveyed ants (Hymenoptera: Formicidae) on 2 sea turtle nesting beaches and at 14 sea turtle hatchery sites in El Salvador to evaluate the potential threat of predaceous ant species to sea turtle eggs and hatchlings. Of the ant species we found, only the tropical fire ant, Solenopsis geminata (F.) (Hymenoptera: Formicidae), is a known threat to sea turtle hatchlings. We found S. geminata at 5 of 7 (71%) and 7 of 30 (23%) baits along sea turtle nesting beaches at Las Bocanitas and Las Isletas, respectively, and within the nest enclosures at 7 of 14 (50%) hatchery sites. Given the widespread use of hatcheries for protecting sea turtle eggs worldwide, we believe it is important for hatchery managers to recognize the potential threat that predaceous ants pose to hatchling sea turtles. Hatchery managers may be unknowingly releasing apparently healthy but stung hatchlings to the ocean, only to have the hatchlings soon die from sting-related impairment. Fortunately, because of the small size of the incubation enclosures, controlling ants at hatcheries by using chemicals that have low toxicity to vertebrates and that degrade quickly (e.g., hydramethylnon) should be safe, simple, and relatively inexpensive.

Loading Eastern Pacific Hawksbill Initiative collaborators
Loading Eastern Pacific Hawksbill Initiative collaborators