Protected areas host important remnants of marine turtle nesting stocks in the Dominican Republic

Abstract

Nesting by marine turtles in the Caribbean has declined considerably, mainly because of human exploitation, but there has previously been no monitoring in the Dominican Republic. We present the first detailed assessment of the status of marine turtle nesting in the country, based on surveys during 2006-2010. Nesting populations of hawksbill Eretmochelys imbricata and leatherback turtle Dermochelys coriacea are of regional importance and the green turtle Chelonia mydas is still present, although nesting in low numbers. The two main nesting sites are within protected areas: the Jaragua National Park in the south-west, important for leatherback turtles (mean of 126 nests per season), and Del Este National Park on Saona Island in the south-east, principally for hawksbill turtles (mean of 100 nests per season). Comparison with historical data suggests all rookeries are profoundly reduced in size. Although the main nesting beaches are within protected areas, illegal egg-take and meat consumption continues there, and also elsewhere in the country.

Core habitat use of an apex predator in a complex marine landscape

“…Focusing research in these areas that can be considered as temporary, site specific or seasonal ranges is crucial to conservation management strategies (Hearn et al 2010, Heupel et al 2010, Revuelta et al 2012, Da Silva et al 2013. By using movement data, home range estimates (first described by Burt 1943 andMcNab 1963) have been used to define boundary lines for protected areas, reveal hotspots and areas of concern and inform policy makers on the effectiveness of management initiatives (Meyer & Holland 2005, Hearn et al 2010).…”

Contextualising the Last Survivors: Population Structure of Marine Turtles in the Dominican Republic

“…During the 2007 and 2008 nesting seasons (from March to October), samples from three nesting marine turtle species were collected within an extensive monitoring project to assess nesting marine turtle abundance and distribution in the Dominican Republic [22] (Figure 1, Table 1). Samples from green turtles (n = 2; DRS), hawksbill turtles (n = 48; DRS n = 33, DRJ n = 15) and leatherback turtles (n = 42; DRJ) were collected from the Jaragua National Park (DRJ/DR) and Saona Island (DRS), with the permission and support of the office of Protected Areas of the Ministry of Environment and Natural Resources of the Dominican Republic Government.…”

“…All mixed stock analysis included population size as a weighting factor as several studies have proved that the inclusion of this factor improved the accuracy of results [41], [81]. Source population sizes (as mean number of nesting females) were taken from the literature [22], [67], [82] (Tables S1 and S3). …”

“…In addition to these threats, turtles are also incidentally captured at sea [19]–[20]. Although marine turtles have been legally protected by law since 1966 in the Dominican Republic [21]–[22] it was estimated that there was an annual capture of between 1000 and 2000 green ( Chelonia mydas ), loggerhead ( Caretta caretta ) and leatherback ( Dermochelys coriacea ) turtles during the 1980s [19]. In addition, a total of 4366 kg of hawksbill ( Eretmochelys imbricata ) shell was exported to Japan between 1970 and 1986 [23].…”

“…The consequences of the accumulation of these threats to the Dominican Republic nesting populations were not properly addressed until a recent study [22], which suggested that the Dominican Republic is an important nesting area for the hawksbill and leatherback turtle and includes some sporadic nesting by green turtles. However, the persistence of threats appears to have led to population reduction and a significant contraction of nesting habitats, with nesting largely restricted to protected areas [14]–[15].…”