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

Abstract

Nesting by three species of marine turtles persists in the Dominican Republic, despite historic threats and long-term population decline. We conducted a genetic survey of marine turtles in the Dominican Republic in order to link them with other rookeries around the Caribbean. We sequenced a 740bp fragment of the control region of the mitochondrial DNA of 92 samples from three marine turtle species [hawksbill (n = 48), green (n = 2) and leatherback (n = 42)], and incorporated published data from other nesting populations and foraging grounds. The leatherback turtle (Dermochelys coriacea) in the Dominican Republic appeared to be isolated from Awala-Yalimapo, Cayenne, Trinidad and St. Croix but connected with other Caribbean populations. Two distinct nesting populations of hawksbill turtles (Eremochelys imbricata) were detected in the Dominican Republic and exhibited interesting patterns of connectivity with other nesting sites and juvenile and adult male foraging aggregations. The green sea turtle (Chelonia mydas) has almost been extirpated from the Dominican Republic and limited inference could be made from our samples. Finally, results were compared with Lagrangian drifting buoys and published Lagrangian virtual particles that travelled through the Dominican Republic and Caribbean waters. Conservation implications of sink-source effects or genetic isolation derived from these complex inter-connections are discussed for each species and population.

A New Approach to Mixed Stock Analysis that Informs on the Management and Conservation of Hawksbill in the Wider Caribbean: the Case of the Legal Fishery in Jardines del Rey, Cuba

“…Other factors that may contribute towards uncertainty are the moderate and sometimes limited sample sizes in some rookeries and aggregations; the quality and sampling frequency in both entities ; the genetic similarity of some rookeries, given that they are isolated reproductively-speaking Carreras et al, 2013); and the limited number of aggregations. This last one is present when adult aggregations are analyzed in our study whose number is a small fraction of the real number of adult aggregations in the WC.…”

“…Sequences of 384 or 740 bp were aligned using Clustal X (Thompson et al, 1997) and matched against published WC hawksbill mtDNA haplotypes Bass, 1999;Dí az-Ferná ndez et al, 1999;Velez-Zuazo et al, 2008;Carreras et al, 2013). The haplotype (h) and nucleotide (π) diversity indices were calculated using the software Arlequin version 3.11 (Excoffier et al, 2005).…”

Revisiting the genetic diversity and population structure of the critically endangered leatherback turtles in the South-west Atlantic Ocean: insights for species conservation

“…Leatherback turtles exhibit complex behaviour, with long migrations between nesting and feeding areas. Most of the worldwide genetic studies of this species have focused on nesting areas (Dutton et al, 1999(Dutton et al, , 2007(Dutton et al, , 2013Carreras et al, 2013;Molfetti et al, 2013). These studies analysed data collected from females when laying eggs in the sand, which poses fewer methodological challenges and is less expensive than sampling in oceanic areas.…”

Juvenile green turtles on the northern edge of their range: mtDNA evidence of long-distance westward dispersals in the northern Pacific Ocean

“…Understanding the dispersal pathway and connectivity in an endangered species plays an essential role in the development of strategies for its effective conservation and management (Boyle et al 2009, Carreras et al 2013. Recently, investigations into mtDNA haplotype frequencies caused by genetic isolation among nesting populations have established the relationship between feeding aggregations and their rookery of origin as well as fa cilitated MSA estimations of the contributions of genetically differentiated nesting populations to foraging assemblages (Pella & Masuda 2001, Bolker et al 2003.…”

“…Successful dispersal is especially critical for endangered species, in which threats may be highly localized and yet have a potentially profound effect over distant areas. Therefore, understanding the dispersal pathway and connectivity of an endangered species will assist in the development of strategies for the effective conservation and management of specific marine organisms (Boyle et al 2009, Carreras et al 2013.…”