An Assessment of Marine Turtle Nesting Rookeries in the Southern Atlantic Coastline of Cameroon: Implications for Management and Conservation

Abstract

Abstract In the present study, we evaluate for the first time marine turtle nesting activity on the coastal beaches of Ebodje, South Region of Cameroon. Regular surveys were carried out over 27 km of coastline in 2013 and over a lesser zone of the studied area with less survey effort from 2014 to 2017. Three marine turtle species were detected nesting in these beaches: the olive ridley (Lepidochelys olivacea), the leatherback turtle (Dermochelys coriacea), and more rarely the green turtle (Chelonia mydas). According to interviews with local inhabitants, the coastal waters of this area are also important for juvenile green turtles and hawksbills (Eretmochelys imbricate) on feeding grounds. Nesting activity concentrates between October and March, with very rare nesting activity detected out of this period. In four nesting seasons, we detected a total of 310 nesting activities, from which 179 clutches were successful; olive ridley was by far the most abundant species (164 clutches), followed by leatherback (11 clutches) and green turtle (4 clutches). The estimated number of olive ridleys in the first nesting season ranged from 30 to 46 turtles. We included information on turtle biometrics and clutch parameters for comparison with closer nesting roockeries and contextualized them with information on human-related threats. Detected threats facing the species were bycatch in artisanal fisheries, beach erosion, light pollution in some beaches, and illegal harvesting of eggs and nesting females at beaches. To mitigate some of these threats, a hatchery was developed on the beach with the highest density of nesting activity. Although there is scarce information about southern Cameroon marine turtle nesting stocks, the levels of nesting and the information on anthropogenic threats reported here indicate that this breeding aggregation is a serious threat and that conservation initiatives are mandated here.