Large-Scale Patterns of Green Turtle Trophic Ecology in the Eastern Pacific Oceans

Trophic position and niche width are fundamental components of a species\u27 ecology, reflecting resource use, and influencing key demographic parameters such as somatic growth, maturation, and survival. Concepts about a species\u27 trophic niche space have important implications for local management and habitat protection, and can shed light about resilience to changing climate for species occurring over broad spatial scales. For elusive marine animals such as sea turtles, trophic niche is challenging to study, and researchers often rely on other metrics, such as isotopic niche, as a proxy. Here, stable isotope analysis (delta C-13 and delta N-15 values) was conducted on bulk skin tissue of 718 green turtles (Chelonia mydas) distributed among 16 foraging areas in the eastern Pacific from the USA to Chile, a range spanning similar to 10,000 km. Compound-specific nitrogen isotope analysis of amino acids (CSIA-AA) was applied to 21 turtles among seven sites. Isotopic niche space was determined via Bayesian ellipse area (BEA) and convex hull area (CHA) analyses of bulk isotope values, which were also used along with amino acid delta N-15 values to determine trophic position (TP). Substantial variability in bulk tissue delta C-13 and delta N-15 values was found within and among sites, and amino acid delta N-15 values confirmed this was largely due to spatial differences in baseline nitrogen isotopic compositions, but also to a lesser extent from TP differences among the green turtle foraging populations. Isotope niche space varied among sites, influenced by the diversity of prey types and relative input of terrestrial- vs. marine-derived nutrients; BEAs were the most suitable measurement of isotopic niche space due to the larger influence of outlying values with the CHA approach. Amino acid isotope-derived TP estimates that accounted for local habitat conditions (e.g., mixed seagrass/macroalgae diet) performed the best among several approaches; TP ranged from 2.3 to 3.6, which indicates an omnivorous diet for most populations. In addition to providing additional spatial resolution for delta C-13 and delta N-15 isoscapes in the eastern Pacific, especially in coastal habitats, this study further establishes CSIA-AA as an effective tool to study the trophic ecology of sea turtles across a variety of food webs and habitats

Genetic connectivity of an endangered shark across nursery areas from the Eastern Tropical Pacific

Defining demographically independent units and understanding gene flow between them is essential for managing and conserving exploited populations. The scalloped hammerhead shark, Sphyrna lewini , is a coastal semi-oceanic species found worldwide in tropical and subtropical waters. Pregnant females give birth in shallow coastal estuarine habitats that serve as nursery grounds for neonates and small juveniles, and adults move offshore and become highly migratory. We evaluated the population structure and connectivity of S. lewini in coastal areas across the Eastern Tropical Pacific (ETP) using both sequences of the mitochondrial DNA control region (mtCR) and nuclear-encoded microsatellite loci. The mtCR defined two genetically discrete geographic groups: the Mexican Pacific and the central-southern Eastern Tropical Pacific (Guatemala, Costa Rica, Panamá, and Colombia). Overall, the mtCR data showed low levels of haplotype diversity ranged from 0.000 to 0.608, while nucleotide diversity ranged from 0.000 to 0.0015. A more fine-grade population structure analysis was detected using microsatellite loci where Guatemala, Costa Rica, and Panamá differed significantly. Genetic diversity analysis with nuclear markers revealed an observed heterozygosity ranging from 0.68 to 0.71 and an allelic richness from 5.89 to 7.00. Relatedness analysis revealed that individuals within nursery areas were more closely related than expected by chance, suggesting that S. lewini may exhibit reproductive philopatric behaviour within the ETP. Findings of at least two different management units, and evidence of philopatric behaviour call for intensive conservation actions for this critically endangered species in the ETP.Universidad de Costa Rica/[801-B6-214]/UCR/Costa RicaNational Secretary of Science and Technology/[FID-156]/SENACYT/EcuadorThe Phoenix Zoo/[no.33297]//Estados UnidosPADI Foundation/[no.32809]//Estados UnidosRufford Foundation/[no.22366-1]//Reino UnidosWaitt Foundation/[no.33297]//Estados UnidosFundación Reserva Ojochal/[]//Costa RicaThe Whitley Fund for Nature/[]/WFN/Reino UnidoSandler Family Foundation/[]//Estados UnidosOsa Conservation/[]//Costa RicaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de BiologíaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Ciencias del Mar y Limnología (CIMAR

Global Spatial Risk Assessment of Sharks Under the Footprint of Fisheries

Effective ocean management and conservation of highly migratory species depends on resolving overlap between animal movements and distributions and fishing effort. Yet, this information is lacking at a global scale. Here we show, using a big-data approach combining satellite-tracked movements of pelagic sharks and global fishing fleets, that 24% of the mean monthly space used by sharks falls under the footprint of pelagic longline fisheries. Space use hotspots of commercially valuable sharks and of internationally protected species had the highest overlap with longlines (up to 76% and 64%, respectively) and were also associated with significant increases in fishing effort. We conclude that pelagic sharks have limited spatial refuge from current levels of high-seas fishing effort. Results demonstrate an urgent need for conservation and management measures at high-seas shark hotspots and highlight the potential of simultaneous satellite surveillance of megafauna and fishers as a tool for near-real time, dynamic management

Opportunities for Development Sustainable in the Coastal Communities of Nandayure (Southern Nicoya, Guanacaste)

En 1998 da inicio el proyecto Playas de Anidación Nicoya Sur, o Plans. Este proyecto coordina acciones con las organizaciones de base, público en general y entidades gubernamentales, para promover la protección, conservación, investigación y manejo de los recursos marino-costeros del cantón Nandayure (Guanacaste). Hasta ahora, en el marco del proyecto Plans se ha logrado consolidar la protección efectiva de cinco playas de anidación de tortugas marinas (Caletas, Costa de Oro, San Miguel, Bejuco y Corozalito), en proyectos conjuntos con las comunidades costeras y el Área Conservación Tempisque (ACT) del Sistema Nacional de Áreas de Conservación (Sinac). Además, en procesos participativos con estos mismos actores se ha logrado la creación de dos Áreas Marinas Protegidas (AMP): una para el Refugio Nacional de Vida Silvestre (RNVS) Caletas-Ario en el 2006 y otra para el RNVS Camaronal en el 2009. En ambos casos se trata de áreas de uso múltiple, donde se prohíben las actividades de pesca destructivas. Actualmente se trabaja en la creación de una nueva AMP que conecte las dos AMP existentes, un área conocida como el “triángulo”, cuyo fin sería fomentar una pesquería sostenible de pargo manchado con enfoque ecosistémico. El proyecto Plans provee beneficios y oportunidades de desarrollo económico a los miembros de las asociaciones de desarrollo comunal y a los pescadores artesanales, y brinda protección efectiva a diversas especies marinas en peligro de extinción y a los diversos hábitats esenciales de los cuales dependen.The Southern Nicoya Nesting Beach project, or PLANS, began in 1998.  The project coordinates actions among development associations, artisanal fishing associations, and community members to promote the conservation, research, protection, and management of the area’s coastal-marine resources of Nandayure. To date, the project Plans has consolidated effective protection of five turtle nesting beaches (Caletas, Costa de Oro, San Miguel, Liana, and Corozalito), in joint projects with coastal communities and Area of conservation Tempisque (ACT) of the National System of Conservation Areas (SINAC). In addition, a participatory process with the same organizations has led to the creation of two Marine Protected Areas (MPAs): one for the National Wildlife Refuge (RNVS) Caletas-Ario in 2006 and one for the RNVS Camaronal in 2009. Both areas carry a multi use designation and prohibit the operation of destructive fisheries. PLANS is currently working on creating a new MPA to connect the two existing MPAs, an area known as the "triangle," which would aim to promote sustainable fisheries for spotted snapper whilst using an ecosystem approach. The PLANS project creates benefits and opportunities to artisanal fishermen and community development associations, as well as protecting a diverse array of endangered marine species and the critical habitats on which they depend

Conservación y actividad reproductiva de tortuga lora (Lepidochelys olivacea) en la playa de anidación solitaria Punta Banco, Pacifico Sur de Costa Rica. Recomendaciones de manejo a través de dieciséis años de monitoreo

Sea turtle nesting activity was monitored in Punta Banco, South Pacific Costa Rica uninterruptedly for sixteen years, accompanied by conservation activities such as nest relocation in hatcheries. Hatching success evaluations were held for “in situ” and relocated nests. We hereby evaluate the reproductive biology of the olive ridley sea turtle (Lepidochelys olivacea), by far the most common turtle sea turtle nesting in Punta Banco (98% of observed turtles). Daily monitoring of nesting activities was held every year from July to December, from 1996 to 2011. We tagged a total of 1 239 turtles and recorded 4 130 nesting events. The number of recorded nesting events per nesting season ranged from 239 in 1996 to 402 in 1999, whereas the number of observed females ranged from 18 in 1996 to 146 in 1999. Nesting females had an average curved carapace length of 66.8cm and an average curve carapace width of 70.7cm. The average clutch size was 96.7, with an observed frequency of 1.07 nests/female and an nesting interval of 19.95 days. Hatching success of “in situ” nests was 61.38%, whereas hatching success for nests relocated into hatcheries was 77.9%.  The L. olivacea population in Punta Banco beach displays a a positive trend. Se realizó un monitoreo de la actividad de anidación de tortugas marinas en Punta Banco, Pacífico Sur de Costa Rica, de forma ininterrumpida por diez y seis años, acompañado por actividades de conservación como la relocalización de los nidos en viveros. Se realizaron análisis de éxito de eclosión para nidos “in situ” y en vivero. Evaluamos por este medio la biología reproductiva de la tortuga lora (Lepidochelys olivacea), por mucho la tortuga más común que anida en Punta Banco (98% de las tortugas observadas). Entre 1996 y 2011, se llevó a cabo el monitoreo diario de las actividades de anidación de julio a diciembre. Marcamos un total de 1 239 tortugas L. olivacea y registramos 4 130 eventos de anidación. El total de anidaciones para L. olivacea varió de 239 en el año 1996 a 402 en 1999, mientras que el número de hembras avistadas varió de 18 en 1996 a 146 en 1999. Las hembras presentaron un largo curvo del caparazón promedio de 66.8cm y ancho curvo de caparazón promedio de 70.7cm. La media para el tamaño de las nidadas fue de 96.7 huevos, con una frecuencia de puesta observada de 1.07 nidos/hembra y un intervalo de puesta observado de 19.95 días. El éxito de eclosión de nidos “in situ” fue de 61.38%, mientras que el éxito de nidos relocalizados en viveros fue de 77.9%. La población de L. olivacea en Punta Banca muestra una tendencia positiva.

New foraging grounds for hawksbill (Eretmochelys imbricata) and green turtles (Chelonia mydas) along the northern Pacific coast of Costa Rica, Central America

Existe poca información disponible sobre los sitios de forrajeo de las poblaciones de tortugas marinas del Pacífico Oriental, lo cual dificulta el diseño de estrategias de conservación tanto en el ámbito nacional como internacional.  Realizamos observaciones en cinco sitios a lo largo del Pacífico Norte de Costa Rica (Cabo Blanco, Punta Coyote, Punta Pargos, Punta Argentina y Bahía Matapalito) entre el 2010-2013, utilizando redes de enmalle tortugueras con luz de malla de 45 cm, con el objetivo de explorar y documentar nuevos sitios de forrajeo.  Estandarizamos la Captura Por Unidad de Esfuerzo (CPUE) como tortugas capturada por 100m de relinga superior por hora de inmersión, el cual varió de 0.06 en Punta Pargos hasta 0.58 en Bahía Matapalito para tortugas carey (Eretmochelys imbricata), y de 0.01 en Punta Coyota hasta 0.10 en Cabo Blanco para tortugas verde del Pacífico (Chelonia mydas).  Encontramos rangos de tamaño específicos por sitio para E.imbricata en Bahía Matapalito y Cabo Blanco, con promedio ± Desviación Estándar (SD) del Largo Curvo de Caparazón (CCL) de 42.46 ± 17.66cm y 61.25±13.08cm respectivamente.  Tan solo se encontró un individuo en los demás sitios con CCL de 49.6cm hasta 60.5 cm.  Se capturaron tortugas verde en tres de los sitios observados, con CCL de 67.67±19.44cm en Cabo Blanco, 69.40±9.40cm en Punta Coyote. y un único individuo en Bahía Matapalito con un CCL de 56.2cm. La ausencia de clases de tamaño de adultos para E.imbricata, así como de clases de tamaño de juveniles para la tortuga verde del Pacífico, enfatiza la complejidad de la distribución específica por especies durante las distintas fases de vida de las tortugas marinas en el Pacífico Oriental, y la necesidad emergente de implementar monitoreos a largo plazo en diferentes sitios a lo largo del Pacífico Norte del país para comprender la conectividad entre hábitats. El presente estudio revela la existencia de sitios de forrajeo frágiles desprotegidos para la tortuga carey y verde en el Pacífico norte de Costa Rica, y sirve de guía para futuras iniciativas de investigación para fortalecer estrategias de conservación en el ámbito nacional e internacional.Scarce information is available on the foraging grounds of Eastern Pacific sea turtle populations, which hinders the design of efficient national and regional conservation strategies. We surveyed five locations along Costa Rica’s North Pacific between 2010-2013 using 45cm mesh turtle tangle nets, with the aim to explore and document new foraging sites (Cabo Blanco, Punta Coyote, Punta Pargos, Punta Argentina, and Bahía Matapalito). We standardized Catch Per Unit Effort (CPUE) as turtles caught per 100m of headrope length per one-hour soak time, which ranged from 0.06 at Punta Pargos to 0.58 in Bahía Matapalito for hawksbill turtles (Eretmochelys imbricata), and from 0.01 in Punta Coyote to 0.10 in Cabo Blanco for Eastern Pacific green turtles (Chelonia mydas). We found site-specific size ranges for E. imbricata with mean ± Standard Deviation (SD) Curve Carapace Lengths (CCL) of 42.46±17.55cm in Bahía Matapalito and 61.25±13.08cm in Cabo Blanco. Only one individual was found at each of the other sites with CCLs from 49.6cm to 60.5cm. Green turtles were found at three of the surveyed locations with mean CCLs of 67.67±19.44cm at Cabo Blanco and 69.40±9.40cm at Punta Coyote and only one individual at Bahía Matapalito with a CCL of 56.2cm. The absence of adult size classes for E. imbricata and of small juvenile size classes for C. mydas at most of these sites stresses the complexity of species-specific distribution during different life stages in the Eastern Pacific and the urgent need to implement long-term monitoring at different coastal sites along the North Pacific to understand habitat connectivity. This study reveals the existence of fragile, non-protected foraging grounds for hawksbill and green turtles in Costa Rica’s North Pacific, and serves as a guide for future research initiatives to strengthen national and regional conservation strategies. Rev. Biol. Trop. 62 (Suppl. 4): 109-118. Epub 2014 Diciembre 01

Diving behavior and delayed mortality of olive ridley seat turtles Lepidochelys olivacea after their release from longline fishing gear

We deployed pop-off satellite archival tags (PSATs) on 14 olive ridley turtles Lepidochelys olivacea and 1 green turtle Chelonia mydas in the eastern tropical Pacific Ocean between November 2001 and June 2003 to determine dive behavior and post-release mortality following interactions with longline fishing gear. Nine olive ridleys and 1 green turtle were captured by longline fishing gear, and 5 free swimming olive ridleys were hand-captured at the surface to serve as controls. Hooks were removed from all longline-caught turtles, with the exception of 1 olive ridley turtle. PSATs remained on control- and longline-caught olive ridleys for an average of 61 and 54 d, respectively (range: 26 to 115) and on the green turtle for 26 d. Olive ridleys spent nearly all of their recorded time within the top 60 m, with very few dives exceeding 100 m. Over 95% of the time was spent between water temperatures of 22 and 28 degrees C and turtles\u27 dive behaviors appeared to be correlated with oceanographic variables (e.g. sea surface temperature and chlorophyll concentration). There were no clear differences evident either in horizontal movements, depth distributions, or associations with specific water temperatures between longline-caught and control turtles. Our data showed only one mortality event, that of a control turtle that died and sank 66 d after being tagged. We conclude that olive ridley turtles that are lightly hooked and handled properly survive and generally behave normally following interactions with shallow-set longline gear