World Status, Exploitation and Trade - WIDECAST

MEXICOMEXICO:CARIBBEAN and GULF OF MEXICOPOPULATION:Chelonia mydasNesting sites C. mydas nests in low numbers at scattered sites on themainland in all the coastal states, and on a number of offshore islands,principally off the Yucatan Peninsula. Available data, mostly from M&rquez(1984b and c) are summarised in Table 141.Nesting numbers The most recent available figures are summarised inTable 141. In 1983 Marquez estimated the 1981 nesting population at beachesinvestigated in the Gulf of Mexico (Tamaulipas to Yucatan/Quintana Roo inTable 141) as perhaps around 256 females (Mirquez, 1984c) and in theCaribbean (Quintana Roo in Table 141) as around 237 (Marquez, 1984b and c),although figures for the offshore cays of Yucatan do not appear to have beenincluded. In 1986 ( in litt ) he gave figures of 210-370 nests in threeareas in the Gulf of Mexico (Rancho Nuevo, Isla Aguada, Rio Lagartos).Parsons (1962) stated that the population nesting on the islands off thenorth-east of the Yucatan peninsula was second in importance only toTortuguero in Costa Rica in the whole of the western Caribbean; the mostimportant sites were Isla Contoy, Isla Blanca, Isla Cancun and theuninhabited eastern side of Isla Cozumel. Green turtles were also said tonest at that time in considerable numbers on Cayo Lobos (Banco Chinchorro)off southern Quintana Roo.Trends in nesting numbers Numbers have evidently decreased, althoughthere is very little historical information. It is thought that the Gulf ofMexico coastline was the nesting area of the Green Turtles that supplied theextensive 19th century Texas turtle fishery which had virtually disappearedby 1900 (Hildebrand, 1981; Carr et al . 1982). The area considered mostlikely to have been important is the extensive length of coastline betweenBoca Jesus Maria in Tamaulipas and Tuxpan in Veracruz; this length of coastnow holds few nesting Green Turtles (Hildebrand, 1981). Before World WarII, Green Turtles are stated to have bred regularly on Playa Washingtonc. 19 km south of the Rio Grande in Tamaulipas but no longer do so(Hildebrand, 1981). In Veracruz, as well as nesting in some abundance northof Tuxpan, especially around Cabo Rojo, Green Turtles are also said to havenested commonly on the coast between Montepio and Cerro San Martin, but arenow rare (Carr et al. . 1981).Nesting season Appears to be roughly June-October (Mirquez, 1976b,1984a, b and c)Foraging sites The most important foraging sites for Green Turtles in thearea appear to be off the west and north of the Yucatan Peninsula, north ofLaguna del Termino and extending over the Campeche Bank. The areas aroundthe offshore cays and reefs (Cayo Arcas-Triangulos, CayoArenas-Snake-Madagascar, Arrecife Alacran) and the Campeche Bank itself arecited as of particular importance (Carr et al . 1982; MArquez, 1984c). Thearea west of this appears to be of minor importance. Carr et al (1982)state that the offshore regions of Tamaulipas do not serve as regularfeeding habitat for any species of sea turtle, and that C. mydas is veryrare in coastal waters off Veracruz, although Caretta and Eretmochelys arereportedly more abundant there. Juvenile and mature C. mydas are reportedlytaken off the Tabasco coast, but only in very small numbers. Mirquez(1984c) cites the areas off Nautla-Cabo Rojo and around the Arrecife Cabezo(both off Veracruz) as turtle foraging sites and includes C. mydas in the348