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Divergent opinions exist as to which species occur and nest on the Pacific beaches of El Salvador. Despite the fact that morphometric data have been gathered from nesting turtles by a variety of Salvadoran institutions, these have not been analyzed, processed and integrated to produce a descriptive document on the species which occur. In this note we attempt to collate the current information and to summarize the facts known about sea turtles in El Salvador.

Morphometric data from nesting turtles gathered in 1984 by the National Parks and Wildlife Service of El Salvador (PANAVIS) were analyzed. In addition, we examined technical reports, including morphometric and morphologic data collected by the Environmentalist Association AMAR since 1989, and data from field observations made by the authors between 1989 and 1995 from nesting and stranded turtles. Data were then compared to the diagnostic features of sea turtles, established by Pritchard et al. (1983), to define the species present.

Four species of sea turtles were documented as occurring: olive ridley turtle (Lepidochelys olivacea), leatherback turtle (Dermochelys coriacea), black turtle (Chelonia mydas agassizi) and the hawksbill turtle (Eretmochelys imbricata).

Olive ridley turtle: We analyzed data gathered from 100 olive ridley hatchlings from ten nests incubated in 1989 by AMAR at Barra de Santiago beach. The average number of vertebral scutes was 6.1 (range= 5-7, sd=0.76); costal scutes: 7.2 (range=5-9, sd=1.36); marginal scutes: 13 (range=13-14, sd=0.41); and all had 4 prefrontal scales. Additionally, between 1989 and 1992, 117 nesting females were measured by AMAR demonstrating a mean curved carapace length (CCL) of 68.9 cm (range=60-85, sd=4.52), and mean curved carapace width (CCW) of 69.6 cm (range=52-89, sd=4.96). These turtles averaged 96.5 eggs (range=24-143, sd=19.15) per clutch. Pores on the inframarginal scutes as a diagnostic feature in Lepidochelys (Pritchard et al. 1983), were examined on 10 nesting turtles and their presence confirmed on all. In 1984 at Playa Hermosa, Isla San Sebastián, PANAVIS reported a total of 42 nesting olive ridley turtle with mean CCL 67 cm (range=50-74, sd=3.89), CCW 66 cm (range=54-80, sd=3.81) and mean clutch size of 93.7 eggs (range=50-130, sd=17.23).

The olive ridley turtle is the most common species in El Salvador and nests year round. However, nesting activity is concentrated during the rainy season between May and October, peaking in August and September (Hasbún & Vasquez 1991). Preserved hatchling specimens are held by AMAR and in the Natural History Museum of El Salvador.

Leatherback turtle: Field data collected by AMAR from the 1992 nesting season at Barra de Santiago, provide a description of the three turtles of this species that nested in that season with an average CCL of 158 cm (Hasbún & Vasquez 1993). Leatherback turtles nest sporadically in El Salvador in the dry months between November and February. Preserved hatchling specimens are held by AMAR and in the Natural History Museum of El Salvador.

Black turtle: The only written descriptive reports of this species are from field observations by PANAVIS at Isla San Sebastian during the 1984 nesting season. For 14 nesting females mean CCL was 68 cm (range=62-71, sd=2.48) and mean CCW was 73 cm (range=63-79, sd=4.09). However, the identification of these individuals is not clear as diagnostic features such as the number of costal scutes and prefrontal scales were not recorded. In addition, these measurements are more characteristic of the smaller olive ridley turtle (CCL between 68-69 cm) than the black turtle (CCL between 82-87 cm, Pritchard et al. 1983). Therefore, it is not possible, in this case, to firmly ascertain that these individuals were black turtles.

AMAR has monitored the nesting population in Barra de Santiago since 1989 where no black turtles have been recorded. Field personnel from PANAVIS working with AMAR at Barra de Santiago report that the black turtle nested at this beach decades ago, but in low numbers compared to olive ridley turtles.

The only complete descriptions of black turtles have been made by the authors of three individuals. The first was documented in 1991 stranded on Barra de Santiago (CCL 87 cm, CCW 79 cm), the second individual was found in 1992 stranded on Isla Conchaguita, Golfo de Fonseca (CCL 67 cm, CCW 55 cm) and the third specimen was documented in 1993 when incidentally captured by a shrimp trawl off the coast of La Herradura (CCL 76 cm, CCW 72 cm). All three specimens possessed two prefrontal scales and four pairs of costal scutes. Their carapaces sharply narrowed at the posterior end and were covered by smooth, non-imbricated scutes. Skulls and carapaces are held in Barra de Santiago's Center for the Interpretation of Nature.

After 10 years of monitoring the nesting population of sea turtles in Honduras close to the Salvadoran border, Cruz et al. (1987) documented a single nesting black turtle and considered its presence as an extremely rare event. It is probable that the same situation applies to El Salvador.

Hawksbill turtle: To date there are no complete records of nesting hawksbill turtles in El Salvador. One field form completed by PANAVIS in 1984 in Isla San Sebastián, reports the nesting of what was considered to be a hawksbill turtle. The following measurements were taken: CCL 63 cm, CCW 65 cm and a track width of 60 cm. In this case, these measurements alone are not sufficient to confirm the species of the nesting turtle, considering that important diagnostic features such as scale and scute counts were not recorded, nor was a clear photographic record provided.

The only hawksbill specimens that have been adequately described as to ascertain their species, have been four individuals: one which was incidentally captured by a shrimp trawler off La Herradura beach in 1991 (CCL 82 cm; CCW 64.5 cm), another which was caught in 1998 by artisanal fishermen inside the Barra de Santiago mangrove estuary (CCL 45 cm; CCW 40 cm) and two which were encountered stranded on Barra de Santiago's beach in 1979 and 1993 (CCL 50 cm, CCW 44 cm and CCL 39 cm, CCW 35.5 cm). These turtles possessed 4 imbricated costal scutes and 4 prefrontal scales. Specimens are held in the Natural History Museum of El Salvador and at Barra de Santiago's Center for the Interpretation of Nature.

Adult hawksbill turtles are generally larger than the olive ridley turtles (Pritchard et al. 1983). However, Salvadoran fishermen describe the hawksbill turtle as being much smaller than the olive ridley. This may be attributed to the reporting of only immature specimens incidentally captured or found stranded. Due to the fact that olive ridley turtles are comparatively small and that this species exhibits variation in numbers of costal scutes and in colouration, it is highly probable that most reported hawksbill turtles are actually olive ridley turtles. In addition, it has been observed in Barra de Santiago that individuals of the freshwater turtle, Trachemys scripta grayii, are sometimes washed out from the estuary after heavy rainfalls and end up on the sandy beach where olive ridley turtles nest. These may also be misidentified and reported as hawksbill turtles.

According to field personnel from PANAVIS, hawksbill turtles nested in Barra de Santiago three decades ago. It is possible that the nesting population of this species has drastically declined due to harvest for their shells. Currently they may only occur in El Salvador sporadically.

Benitez (1985) reports the occurrence and nesting of the loggerhead turtle (Caretta caretta) in El Salvador. However, data or evidence to support this contention was not provided. Marquez (1990) agrees that this identification was not clear and most likely corresponded to olive ridley turtles. In addition, both the loggerhead and olive ridley turtles have been historically misidentified in the East Pacific, especially in Mexico and Chile (Frazier 1985).

In conclusion, nesting of olive ridley and leatherback turtles in El Salvador is confirmed. Whilst the black and hawksbill turtle may nest occasionally in this region, their presence has not been conclusively documented. Their stranding however on this coast can be taken as an indication of their presence in the waters of El Salvador.

Acknowledgements: Appreciation is extended to the US Fish and Wildlife Service and to Jack Woody, Richard Byles, Paddy Tatum, Emilio León, Angela Formia, Pearl Seidman, Carlos Thomas, Penny Altman and Roman Ruiz for their support throughout this research.

BENITEZ, M. 1985. Informe Nacional de El Salvador. Primer simposio sobre tortugas marinas del Pacifico Americano. Universidad de Costa Rica. San Jose, Costa Rica. 7pp.

CRUZ, G.A., M. ESPINAL & O. MELENDEZ. 1987. Primer registro de anidamiento de la tortuga marina Chelonia agassizi en Punta Raton, Honduras. Revista Biologia Tropical 35(2):341-343.

FRAZIER, J. 1985. Misidentifications of sea turtles in the
East Pacific: Caretta caretta and Lepidochelys olivacea. Journal of Herpetology. 19 (1):1-11.

HASBÚN, C. R. & M. VÁSQUEZ. 1991. Proyecto de conservación de la tortuga marina en Barra de Santiago, El Salvador, Agosto-Diciembre 1990. Presentado a US Fish and Wildlife Service y World Wildlife Fund. AMAR, El Salvador. 45pp.

HASBÚN, C. R. & M. VÁSQUEZ. 1993. Proyecto de conservación de la tortuga marina en Barra de Santiago, El Salvador, Agosto-Diciembre 1992. Presentado a US Fish and Wildlife Service y World Wildlife Fund. AMAR, El Salvador. 56pp.

MARQUEZ, R. 1990. Sea turtles of the world. FAO Fisheries Synopsis. No. 125. Vol. 11. Rome, FAO, 81pp.

PRITCHARD, P., P. BACON, F. BERRY, A. CARR, J. FLETMEYER, R. GALLAGHER, S. HOPKINS, R. LANKFORD, R. MARQUEZ, L. OGREN, W. PRINGLE, H. REICHART & R. WITHAM. 1983. Manual sobre técnicas de investigación y conservación de las tortugas marinas. Segunda Edición. K. A. Bjorndal & G. H. Balazs, Editors. Center for Environmental Education, Washington, D.C. 134pp.