Didiher Chacon1, David Rojas2, Adi Barash2and Claudio Quesada3

1 WIDECAST Latin American Program Coordinator 2 WIDECAST Osa Program

3 WIDECAST Costa Rica Caribbean Projects

During the second half of 2010, we conducted 30 in-water surveys in the Dulce Gulf in the Osa region of Costa Rica (8º 38.4351 N, 083º 22.1342 W) in order to provide information about the use of foraging ecosystem and abundance of the specie in the area. We deployed 250 m long sea turtle entanglement nets at different locations inside of the Gulf. All captured turtles captured tagged and their biometrics were recorded, also we collected tissue samples for DNA studies. A total of 102 green turtles were collected during 322 hours of effort, resulting in a CPUE of 0.3167 turtles/hour. The mean size of captured turtles 78.71 cm CCL (range = 53.5-91.8 cm). There were only seven recaptures during the project period. Only adult females and subadults were observed. The highest rate of capture was associated with tidal period, likely associated with movements into or away from the foraging ground; we found no evidence of seasonal changes in abundance, but the CPUE show a drop during November and December. A satellite tag was deployed on adult female, to monitor her foraging movements inside the Dulce Gulf. An evaluation of the foraging areas revealed large aggregations of Gracilaria sp. on rock button in combination with sand, mud, and sponge areas, particularly along mangrove coastline (Rhizophora mangle) and river mouths. The most important threats observed were sedimentation from rivers, plastic litter, incidental interactions with fishing gear, and presumably pesticides due to runoff from agriculture activities as oil palm plantations, cattle raising and rice plantations.Key words: Costa Rica, Pacific green, foraging, Osa.

IntroductionCosta Rica (Fig. 1) has 1,164 km of Pacific coastline with a great diversity of ecosystems, including rocky, sandy and muddy beaches, cliffs, mangroves, estuaries, is-lands, gulfs and bays. The southern area is especially unique because of high biodiversity and endemism and relative low coastal development.

The Osa Region (Fig. 2) includes 3 counties – Osa, Corredores, Golfito – in the Puntarenas Province with an area of 4304.8 km2. Thirty-four percent of this area is protected by 17 designated reserves: 3 National Parks, 1 Biological Re-serve, 10 Wildlife Refuges, 1 Forestry Reserve, and 2 wetlands (Obando & García 2000, Kappelle et al. 2002 and Quesada & Cortés, 2006).

The Dulce Gulf (Fig. 2) has 50 km of length with 10-15 km of with, including an area of 680 km2 with an effective sill of about 60 m. Inner basin waters are just over 200 m in depth (Svendsen et al. 2006), although the gulf’s deepest waters are reported by local fishermen and guides to surpass 300-400 m in the cratered center of Rincon Bay at the most northwesterly point of the Gulf. The coastline include cliffs cover by Tropical Rain Forest, some moody and sandy beaches, small areas of mangroves and some patches of marine grass (Hebbeln et al 1996). The maximum deep of this Gulf is 260 m and the morphology doesn’t permit the good circulation of waters producing in some areas

anoxia in the bottom of the Gulf. The circulation of the marine water in the Gulf is stimulated by the contribution of fresh water from the rivers with mouths to the Gulf.

Golfo Dulce is a curved tropical fiord-like embayment located along the south Pacific coast of Costa Rica. It is held against the mainland by the Osa Peninsula and four main rivers supply fresh water into the embayment: Rincon, Esquinas, Tigre and Coto Colorado. Davis (1997) found low rates of pesticides in the water of the Gulf and Quesada & Cortes (2006) report high rates of bacteries and organic trash from agricultural activities.

Considering the wealth of biodiversity in the Osa region, the scarcity of information about the status of depleted sea turtle populations, and a history of marine conservation areas, we have identified a strong opportunity to support the protection and conservation of these reptiles and their critical habitats, particularly with regards to the “black sea turtle” and the Pacific Hawksbill sea turtle declared by the IUCN RedList to be endangered and critical endangered species, respectively.The green turtle (Chelonia mydas agassizi) (Fig. 3), is listed as globally endangered on the IUCN Global Red List (IUCN 2004). In the eastern Pacific it is commonly called black turtle, due to morphological and color variations and will be referred to as such in this study. The black turtle is found in the Costa Rica Pacific during all life history stages and the coastal waters of Osa Gulf of Costa Rica provide important feeding and developmental habitat, similar locations are in Gulf of California, México and Poza del Nance in Guatemala. Apparently, the most important nesting beaches of this specie are in Nicoya Peninsula and North of Guanacaste (Nancite, Santa Rosa, Cabuyal, Nombre de Jesús and Punta Pargo), other regional nesting

population occur in Pacific coast of Nicaragua, Michoacán, Revillagigedos and Tres Marias Islands in México and Galapagos Islands, Ecuador (Koch et al. 2007).

The East Pacific green turtles may spend up to 20 years or more in these near-shore habitats before reaching maturity (Seminoff et al., 2002; Seminoff, 2004; Koch et al., 2007) and the removal of only a small number of individual turtles from this environment could substantially limit or impede population recovery (Crouse et al., 1987; Crowder et al., 1994; Crouse, 1999).

Many fishermen with several years experience in Dulce Gulf commented on the decline in numbers of sea turtles seen these days, saying the drop is at least 30%. (Bessesen 2010).

Therefore, understanding green turtle spatial use in these areas is a priority for conservation efforts. Nevertheless, the movements and habitat use of sea turtles that inhabit coastal foraging environments is poorly understood in contrast to migrating adult females (Seminoff et al., 2002; Seminoff and Jones, 2006; Schofield et al., 2007; Godley et al., 2008; Hazel, 2009).

Tracking the movements of free living animals, such as sea turtles, is fundamental to understanding their feeding ecology, migratory behavior, habitat use, general life

history parameters, and conservation needs (Cooke et al., 2004; Cooke, 2008; Costa et al., 2010).

Our general objective was Improve the conservation status of the Pacific green at foraging locations along the Golfo Dulce coast of Costa Rica.

Material and MethodsTurtles were captured using cotton entanglement nets (150 m long, 50 cm stretched mesh, Fig 4) specifically designed to catch sea turtles and made in Bocas del Toro, Panamá. Captured turtles were able to surface and breathe because the nets have very little weight on the lead line. The nets soaked for seven hours and were monitored at regular intervals (1 h) for entangled turtles. The nets were set during low tide at various sites in front of Caballero, Colibrí and Escondido Port Area with most capture effort conducted at day. After capture, turtles were up board and standard measurements (curved carapace length and width, length and with of plastron, total and partial tail length, and general body condition) were conducted, also tissue, blood and mucus from eyes, cloaca and nose samples were collected. No turtles were kept on board for longer than one hour, all were keep humid and under shade. All measurements were recorded on standardized sea turtle data sheets. After measurements were completed, turtles were tagged using metal Inconel tags (National Band and Tag Company, Newport, KY), applied proximal and adjacent to the second large scale on each front flipper, following Beggs and Eckert (2007). We defined sexual maturity as 77.3 cm SCL according Seminoff et al. (2003) and Senko et al. (2010). A satellite tracker donated by National Aquarium in Baltimore was installed on a mature female (Fig. 5) during September 2010.

ResultsWe capture in the foraging grounds at Golfo Dulce (Fig. 6 and 7), 102 green turtles all of the presumably females, in several study stations inside. Each turtle was measured and examined and samples of blood, tissue, mucus on eyes, cloaca and nose were collected for studies in partnership with National University Research team. According, Seminoff et al. (2003) and Senko et al. (2010) the sexual maturity of the green turtle is around 77.3 cm SCL. Also, Fonseca, L. (pers. Comm.) established for the green turtle nesting rookery in Santa Rosa National Park, north of Costa Rica, that the minimum SCL for their nesters was 78 cm.

Fig. 8: Distribution of total curve length for the green turtles sampled.

Based on this information we can conclude that the green turtle captured in water during our activities at least 50% of them were mature specimens. This situation show the importance of the conservation of this Dulce Gulf population because represent a critical reproductive cohort of the Eastern Pacific population. During the sampling of March 2011, the WIDECAST team capture a female carrying tags from Galapagos shown a link between the south Pacific areas of Costa Rica and Galapagos Islands. This turtle was tagged in Quinta Playa at Isabela Island during the nesting season in April 2010 (Parra, comm. Pers). The straight distance between these two points is at least 1,300 km (Fig. 9).

Fig 9. Galapagos Islands

The Capture per Unit Effort (CPUE) reported for the internal area of the Dulce Gulf is one green turtle each 3 hour of deployed net time, 8 re-captures was reported. In general terms, not external evidence of fibropapiloma was found and only marine leeches were collected from some individuals. The CPUE for greens is one of the most important issues because show the high density of this specie in the zone and the critical habitat that represent the Dulce Gulf for the Eastern Pacific Green population. Hancock (2007) reported a CPUE of 0,0252 for Cahuita National Park in Costa Rica.We found a second morphotype for Green Turtle (Fig. 10) reported in Hawaiian Islands, Australia and South America, but not reported nesting in Costa Rica. The importance of the genetic studies in the Sea Turtle populations of Osa region need to be determine, particularly their specific contribution for the regional population status.One green turtle was tagged with satellite tag and during 61 days show their movements inside the Dulce Gulf presumably in foraging activities (Fig. 11). More support for

this activity is needed to understand the use of critical habitats and the patterns of use around the year in Dulce Gulf.

Recommendations• Foraging movements need be studied.• Genetic stock studies need to be developed.• Activities to reduce the sediments over sea grass need to be developed.• Information about this study needs to be shared with the responsible

authorities of the Non-take fishing zone at Dulce Gulf.

References:Bessesen B. L. 2010. Project Report and Summary of Multi-Species Marine Sighting Survey in Golfo Dulce, Costa Rica. FOO. Osa, Costa Rica.

Cooke, S.J., 2008. Biotelemetry and biologging in endangered species research and animal conservation: relevance to regional, national, and IUCN Red List threat assessments. Endang. Spec. Res. 4, 165–185.

Cooke, S.J., Hinch, S.G., Wikelski, M., Andrews, R.D., Kuchel, L.J., Wolcott, T.G., Butler, P.J., 2004. Biotelemetry: a mechanistic approach to ecology. Trends Ecol. Evol. 19, 334–343.

Costa, D.P., Robinson, P.W., Arnould, J.P.Y., Harrison, A.L., Simmons, S.E., Hassrick, J.L., Hoskins, A.J., Kirkman, S.P., Oosthuuizen, H., Villegas-Amtmann, S., Crocker, D.E., 2010. Accuracy of ARGOS locations of pinnipeds at-sea estimated

using fastloc GPS.

Crouse, D.T., 1999. The consequences of delayed maturity in a human dominated world. Life in the slow lane: ecology and conservation of long-lived marine animals. Proceedings from The American Fisheries Society Symposium. Bethesda, MD, USA.

Crouse, D.T., Crowder, L.B., Caswell, H., 1987. A stage-based population model for loggerhead sea turtles and implications for conservation. Ecology 68, 1412–1423.

Crowder, L.B., Crouse, D.T., Heppell, S.S., Martin, T.H., 1994. Predicting the impact of turtle excluder devices on loggerhead sea turtle populations. Ecol. Appl. 4, 437–445.

Davis, P. 1997. A geological investigation of the Golfo Dulce sediments, Costa Rica. M.Sc. Thesis, Univ. Toledo, Toledo, Ohio. 128 p.

Eckert, Karen L. y Jennifer Beggs. 2006. Marcado de Tortugas Marinas. Un Manual de Métodos Recomendados. Red de Conservación de Tortugas Marinas del Gran Caribe (WIDECAST). Informe Técnico No. 2. Edición Revisada. Beaufort, North Carolina USA. 40 pp.

Godley, B.J., Blumenthal, J.M., Broderick, A.C., Coyne, M.S., Godfrey, M.H., Hawkes, L.A., Witt, M.J., 2008. Satellite tracking of sea turtles: where have we been and where do we go next? Endang. Spec. Res. 4, 3–22.Hancock, J. 2007. Informe de actividades proyecto In-water. Parque Nacional Cahuita. Asociación

WIDECAST.Hazel, J., Lawler, I.R., Hamann, M., 2009. Diving at the shallow end: green turtle behavior in near-shore foraging habitat. J. Exp. Mar. Biol. Ecol. 371, 84–92.

Hebbeln, D., D. Beese & J. Cortés.1996. Morphology and sediment structures in Golfo Dulce, Costa Rica. Rev. Biol. Trop. 44 (Supl. 3): 1-10.

Kappelle, M., M. Castro, H. Acevedo, L. González & H. Monge. 2002. Ecosistemas del Área de Conservación Osa (ACOSA). INBio, Santo Domingo, Heredia. 496 p.

Koch, V., Brooks, L., Nichols, W.J., 2007. Population ecology of the green/black turtle (Chelonia mydas) in Bahia Magdalena, Mexico. Mar. Biol. 153, 35–46.

Obando, V.; García, R. 2000. Estrategia de conservación y uso sostenible de la biodiversidad. Area de Conservación Osa. MINAE-SINAC-INBio. GEF-PNUD-NORAD. San José, Costa Rica. 36p.

Quesada, M. A. & J. Cortés. 2006. Capítulo XII, Golfo Dulce, Pp. 167-176. In V. Nielsen-Muñoz & M. A. Quesada-Alpízar (eds.), Ambientes Marino Costeros de Costa Rica. Comisión Interdisciplinaria Marino Costera de la Zona Económica Exclusiva de Costa Rica, Informe Técnico. CIMAR, CI, TNC, San José, Costa Rica.

Schofield, G., Bishop, C.M., Katselidis, K.A., Dimopoulos, P., Pantis, J.D., Hays, G.C., 2009. Microhabitat selection by sea turtles in a dynamic thermal marine environment. J. Anim. Ecol. 78, 14–21.

Seminoff J, Jones TT, Resendiz A, Nichols WJ, Chaloupka MY. 2003. Monitoring green turtles (Chelonia mydas) at a coastal foraging area in Baja California, Mexico: multiple

indices describe population status. J Mar Biolog Assoc UK 83:1355– 1362

Seminoff JA, Resendiz A, Nichols WJ. 2002. Diet of the east Pacific green turtle, Chelonia mydas, in the central Gulf of California, Mexico. J Herpetol 36:447–453

Seminoff, J.A., 2004. Red List Global Status Assessment: Green Turtle (Chelonia mydas). IUCN/SSC World Conservation Union/Species Survival Commission, Marine Turtle Specialist Group, Gland, Switzerland.

Seminoff, J.A., Jones, T.T., 2006. Diel movements and activity ranges of green turtles (Chelonia mydas) at a temperate foraging area in the Gulf of California, Mexico. Herpetol. Cons. Biol. 1, 81–86.

Senko, J., Lopez-Castro, M., Koch, V., Nichols, W.J., 2010. Immature East Pacific green turtles (Chelonia mydas) use multiple foraging areas off the Pacific Coast of Baja California Sur, Mexico: first evidence from mark-recapture data. Pac. Sci. 64, 125–130.

Svendsen, H., R. Rosseland, S. Myking, J.A. Vargas, O.G. Lizano & E.J. Alfaro. 2001. A physical oceanographical study of Golfo Dulce. Preliminary Report. Geophysical Institute, Univ. Bergen and CIMAR, Univ. de Costa Rica.

Acknowledgements:We want to thank the People Trust for Endangered Species (PTES), Crocodile Bay Lodge, Humane Society International for the support received to this research. We also thank to International Sea Turtle Society, Western Pacific Regional Fishery Management Council, U.S. Fish and Wildlife Service, U.S. National Marine Fisheries Service, Disney Worldwide Conservation Fund fro the support to attend this symposium.

NEW PACIFIC GREEN TURTLE FORAGING GROUND AT DULCE GULF, SOUTH PACIFIC COAST OF COSTA RICA

Fig. 11: Map of the green turtle movements in the Dulce Gulf.

Fig. 2: Osa region.

Fig. 1: Map of the country.

Fig. 3: Eastern Pacific Green Turtle.

Fig. 4: Turtle captured in the net.

Fig. 5: WIDECAST team releasing a Green Turtle with Satellite Tracker.

Fig. 6: Underwater view of the sea grass beds in Osa region.

Fig. 7: Low tide view of the seagrass beds in Osa region.

Fig. 10: Second morphotype found in Osa region.Fig. 3: Eastern Pacific Green Turtle.

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Didiher Chacon1, David Rojas2, Adi Barash2 and Claudio Que-sada3

1 WIDECAST Latin American Program Coordinator 2 WIDECAST Osa Program

3 WIDECAST Costa Rica Caribbean Projects

This research was developed during the second semester of 2010 in the Osa region (9º 09.2289 N, 083º 45.1420 W hasta 8º 22.3996 N, 083º 08.0714 W), southeastern Pacific coast of Costa Rica in order to evaluate the status of the Pacific Hawksbill nesting and conservation of this specie, in general. A survey apply to local coastal communities was developed to guide researchers to nesting hot spots and to raise information about uses and threats of the specie. At the same time, team of researchers ran beach nesting observation and monitoring from Uvita location to Punta Banco, including coastline inside of Dulce Gulf, after confirm the nesting, the nest was marked and weekly visits where developed until hatch date when exhumation was developed. From each nest success rate were estimated and tissue sample were collected. When females were found biometric were collected and recorded, also tissue samples for DNA studies were collected. The results show that the nesting in Osa region is around 50 nests in Isla Violín, Río Claro, Danta, San Jocesito, Corcovado, Llorona, Pejeperro, Sombrero, Platanares and Punta Banco, in average we reported 5 nests/beach (1-15 nests) with a maximum in Corcovado-Llorona section. An average of 148 eggs/nest and 91.1% success rate in n=29 for in situ nests. The incidental fishing by nets and hand lines, trade of carapace to produce cock fights spurs and damage to critical habitats were the main threats for the Osa Hawksbills.

Sea turtles throughout the Eastern Pacific are heavily depleted from levels of historical abundance (e.g., Pacific leatherbacks have sustained declines of >95% in the last 15 yrs), mainly due to over-exploitation, bycatch, and habitat destruction. All six species of sea turtle found in the Eastern Pacific are classified on the IUCN Red List of Threatened Species throughout their global ranges as “Endangered” (green turtle, Chelonia mydas; loggerhead turtle, Caretta caretta; olive ridley, Lepidochelys olivacea) or “Critically Endangered” (hawksbill turtle, Eretmochelys imbricata; leatherback turtle, Dermochelys coriacea). Threats have accumulated over long periods of time throughout a population’s range; thus, declines result from a combination of factors, both domestic and foreign.

The hawksbill sea turtle (E. imbricata) is distributed circum-tropically and unique to this species of sea turtle, and one of the principal reasons for its decline, is the collection of its elaborately coloured keratinous shell (tortoiseshell, or carey) for fabrication of items such as bracelets and rings (Carr, 1952; Parsons, 1972; King, 1982; Chacon & Arauz, 2002; Mortimer & Donnelly, 2008). Entire individuals (dissected) are also commonly collected and sold as stuffed curios or souvenirs (King, 1982).

Hawksbill turtles (Fig. 1) are particularly threatened in the Pacific Ocean where they are approaching regional extirpation (NMFS & USFWS, 1998; Mortimer & Donnelly, 2008). This is especially the case in the eastern Pacific, where the species was once considered common from Mexico to Ecuador (Cliffton et al., 1982) but is now the rare sea turtle in the Eastern Pacific (EP) (Cornelius, 1982). As in other parts of the world, the historical reduction in numbers in EP is closely tied to the tortoiseshell trade, as well as to egg harvest and fisheries bycatch (Mortimer & Donnelly, 2008).

Costa Rica (Fig. 2) has 1,164 km of Pacific coastline with a great diversity of ecosystems, including rocky, sandy and muddy beaches, cliffs, mangroves, estuaries, is-lands, gulfs and bays. The southern area is especially unique because of high biodiversity and endemism and relative low coastal development. The Osa Region (Fig. 2) includes 3 counties – Osa, Corredores, Golfito – in the Puntarenas Province with an area of 4304.8 km2. Thirty-four percent of this area is protected by 17 designated reserves: 3 National Parks, 1 Biological Re-serve, 10 Wildlife Refuges, 1 Forestry Reserve, and 2 wetlands.

Considering the wealth of biodiversity in the Osa region, the scarcity of information about the status of depleted sea turtle populations, and a history of marine conservation areas, we have identified a strong opportunity to support the protection and conservation of these reptiles and their critical habitats, particularly with regards to the Pacific Hawksbill sea turtle.

The Dulce Gulf (Fig. 3) has 50 km of length with 10-15 km of with, including an area of 680 km2 with an effective sill of about 60 m. Inner basin waters are just over 200 m in depth (Svendsen et al. 2006), although the gulf’s deepest waters are reported by local fishermen and guides to surpass 300-400 m in the cratered center of Rincon Bay at the most northwesterly point of the Gulf. The coastline includes cliffs cover by Tropical Rain Forest, some moody and sandy beaches, small areas of mangroves and some patches of marine grass (Hebbeln et al. 1996). The maximum deep of this Gulf is 260 m and the morphology doesn’t permit the good circulation of waters producing in some areas anoxia in the bottom of the Gulf. The circulation of the marine water in the Gulf is stimulated by the contribution of fresh water from the rivers with mouths to the Gulf.

Golfo Dulce is a curved tropical fiord-like embayment located along the south Pacific coast of Costa Rica. It is held against the mainland by the Osa Peninsula and four main rivers supply fresh water into the embayment:

Rincon, Esquinas, Tigre and Coto Colorado. Davis (1997) found low rates of pesticides in the water of the Gulf and Quesada & Cortes (2006) report high rates of bacteries and organic trash from agricultural activities.

The studies of plankton in the Osa area show a mixture between neritic and oceanic groups (Guzman & Obando 1988), Guzman et al. (1990) inform about impacts of red tide over coral reefs located in El Cano Island.

Osa region have the bigger area of mangroves of the country with 16700 ha (42,8% of the total area for Costa Rica), mainly cover by Rhizophora racemosa and Pelliciera rhizophorae (Jiménez & Soto 1985, Lizano et al. 2001, Kappelle et al. 2002). The most common species of coral are Porites lobata, Pocillopora damicornis, Pocillopora elegan and Psammocora stellata (Cortés 1990 & 1997).

Material and MethodsThis project was developed since April 2010 to March 2011.

During the first two months a survey was performed (n=150), especially in the coastal area between Punta Uvita (North of Osa) and Punta Burica (South of Osa), to better understand local perception of the Hawksbill turtle, its nesting, situation, and challenges.

Simultaneously, a sampling of all the sections of sandy beaches and semi-rocky shores between Punta Uvita and

Burica was performed, both by boat and on foot. We were accompanied by a member of the sea turtle conservation group COJIPOZA from Nicaragua. We focused on nesting sites similar to the ones in Nicaragua, such as sandy beaches close to mangrove swamps. Nesting maps of the Hawksbill turtle in Osa were created (Fig. 4).

Once we determined the most important beaches, at least during this season and during the sampling time, local group partners of WIDECAST as well as WIDECAST staff were deployed on site to patrol the beach and protect the nests.

Each female sea turtle was identified, and each nest was marked and later exhumed to determine its hatching success rate. A photographic archive of most of these activities was created.

Most of the nests were protected in a natural way or relocated (e.g. Corcovado), but some nests such as the ones in San Josecito and Río Claro were protected through use of a hatchery, managed by partners as Osa Foundation (Fig. 5). The average success rate for natural nests were 91.1%, the number of eggs per nest in average for Osa region was 148 eggs/nest.

Natural and human depredations were documented, and the percentage of nests lost to these causes was calculated. A network of local, regional, and national organizations was created as an effective conservation tool. This network worked together to increase their knowledge, to improve their conservation impact, and to improve their ability to respond in case of stranding or arrival of wounded sea turtles.

ResultsThe project is running and until now we completed all objectives successfully. We developed and conducted a field survey from Ballena Marine Park to the Burica Peninsula (approx. 310 km of sandy beaches, rocky shore, estuaries and mangroves) in order to document nesting by Hawksbill sea turtles. The survey took place between May and September 2010 and was led by a local sea turtle expert from COJIZOPA in the Estero Padre Ramos community, one of the most important sites for Hawksbill nesting in the region. The survey involved both terrestrial and at-sea activities in order to successfully investigate more than 50 beaches. Each beach was visited by foot and sea turtle crawls, “body pits”, and other nesting signs were recorded on standardized data forms. Nesting was confirmed (by direct monitoring and protection of nests) at Violin Island (10), San Josecito (4), Río Claro (3), Corcovado (18), Sombrero (7) and Platanares (10), (Fig. 4). But we report by interviews with locals other list of places that occasionally have nesting as Punta

Banco, Lapa Roja, Ganado, Cusinga Beach.

Information collected from each nest included location,

hatch success rate, and tissue sample (skin and muscle sample for mtDNA studies). We made every attempt to protect each nest from erosion and depredation. As a result, only 10% (n=5) of the nests were lost to natural predation and 5% (n=2) to (human) poaching at least in the places that we confirm some kind of nesting.

An interview survey was developed and conducted with 150 local interviewees, and one of the outcomes of this activity was to compile a list of potential nesting beaches in the region including areas that occasionally have nesting and we don’t find any activity during this season. Also, to have better idea about the conservation status of the specie (Figs. 6-7), including the current trade of carapace to Panamá to make cock fight spurs from Los Mogos area in Golfito zone (CR) to Puerto Armuelles (PA), (Fig. 8).

We have concluded that Hawksbill sea turtle nesting occurs annually between Ballena Marine Park and the Burica Peninsula, but that it occurs at very low densities (approximately 50 nests/year, Fig. 9) and infrequent in some places. We did not document any take of Hawksbill nesting turtles by humans (only the theft of eggs, see above) or by the interviews. No Hawksbills were tag because the nesting is disperse, low number of nesting females and few personnel in charge, but we have two satellite trackers waiting to be installed in future to document postnesting migrations particularly in San Josecito Beach because is small, stable nesting and very good marked nesting season.

In the same way, our team cooperated with a National University (Costa Rica) research team by providing expertise on studies of fibropapillomatosis and blood-sampling of the stranded turtles. Also, currently WIDECAST scientist is the official technical adviser for La Tortuga Beach Project to management of their hatchery, also receive the request to be the same adviser for Fundacion Osa in San Josecito

beach during 2011 season.

The unanticipated results come from the information obtained from the survey as it succeeds in not only locating nesting sites, but also in identifying ways to trade, possible capture sites, as well as feeding areas of the species.

Conclusions

Nesting of Hawksbill in the region is dispersed and in similar quantities to the ones in the Costa Rican Caribbean.

Because the Hawksbill nesting area is large, the most effective protection mechanism is through a network of partners.

The social survey was a very effective and specific support tool to direct the conservation actions.

Shell trade has yet to disappear and in order to eliminate it is necessary to both report it to authorities and to confiscate the shells. It constitutes a binational trade (Costa Rica-Panama).

Sediments, solid garbage and the lost of critical habitats by coastal development are the main threats in the Dulce Gulf.

Diet preferences and food selection of sea turtles have been poorly studied in spite of the relevance of these kind of studies for understanding ecological requirements and management strategies, especially for endangered species because the better understanding of their habitat might be part of the successful conservation strategies.

Nonetheless, data generated from these studies will be vital for future sea turtle conservation efforts. Hawksbill sea turtles inhabit neritic foraging areas in tropical and subtropical regions throughout the world’s oceans. Due to overexploitation of eggs, shell and meat as a food resource and, to a lesser extent, incidental mortality relating to marine fisheries and degradation of marine and nesting habitats, hawksbill turtle populations have declined throughout the world (Groombridge & Luxmoore, 1989). Red Data Book (Hilton-Taylor, 2000) and are included in Appendix 1 of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).

Recommendations• Continue with the location of critical nesting areas of Hawksbill in the area.

• Develop activities against the poaching of eggs.

• Develop activities in relationship with Responsible Fishing Zone (RZF) declared by IN-COPESCA to the sea turtles will be consider a key element in the management of the RZF.

• Develop activities to reduce the threats from main land.

• Create and propose to local communities alternative livelihoods to reduce their im-pacts over sea turtles and critical habitats.

ReferencesBessesen B. L. 2010. Project Report and Summary of Multi-Species Marine Sighting Survey in Golfo Dulce, Costa Rica. FOO. Osa, Costa Rica.

CARR, A.F. 1952. Handbook of Turtles: The Turtles of the United States, Canada, and Baja California. Comstock Publishers, Ithaca, USA.

CHACON, D.& ARAUZ, R. 2002. Diagnostico sobre el comercio de las tortugas marinas y sus derivados en el istmo centroamericano.

Red Regional para la Conservacion de las Tortugas Marinas en Centroamerica. San Jose, Costa Rica.

CL IFFTON, K., CORNEJO, D.O. & FELGER, R.S. 1982. Sea turtles of the Pacific coast of Mexico. In Biology and Conservation of Sea Turtles (ed. K.A. Bjorndal), pp. 199–209. Smithsonian Institution Press, Washington, DC, USA.

Cornelius SE. 1982. Status of sea turtles along the Pacific coast of Middle America. In: Bjorndal KA (ed) Biology and conservation of sea turtles. Smithsonian Institution Press,

Washington, DC, p 211–219

Cortés, J. 1990a. Coral reef decline in Golfo Dulce, Costa Rica, eastern Pacific: anthropogenic and natural disturbances. Tesis Doctoral, Univ. Miami, Miami, Florida. 147 p.

Cortés, J. 1990b. The coral reefs of Golfo Dulce, Costa Rica: distribution and community structure. Atoll Res. Bull. 344: 1-37.

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Nesting of Pacific Hawksbill Turtle in Osa region, southeastern Pacific coast of Costa Rica.

Figure 1: Osa nesting females trapped in tide pools.

Figure 2: Costa Rica Map

Figure 3: Osa region location

Figure 4: Nesting locations at Osa region.

Figure 5: Hatchery in San Jocesito Beach during exhumation of Hawksbill nest.

Figure 9: Hawksbill hatchlings in Platanares

beach, Osa region.

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Fig. 6: Abundance of each Sea Turtle Species based on local perceptions.

Figure 7: Value associated to the specie, based on local perceptions.

Figure 8: Cock fight spurs made by turtle shell.

Acknowledgements:We want to thank the People Trust for Endangered Species (PTES), Crocodile Bay Lodge, Humane Society International for the support received to this research. We also thank to International Sea Turtle Society, Western Pacific Regional Fishery Management Council, U.S. Fish and Wildlife Service, U.S. National Marine Fisheries Service, Disney Worldwide Conservation Fund fro the support to attend this symposium.