72 The main objective of this study is therefore to provide a first-time assessment of the connectivity pattern between the RP and the GLS nesting areas at different temporal scales, using concurrently three different techniques: (i) Telemetric surveys were used to evaluate the spatial dispersion of adult loggerhead females within the breeding season and to test their fidelity to their nesting grounds at an intra-seasonal scale. They derived from a collaborative program, designed to identify migratory corridors and foraging grounds of females nesting in New Caledonia (Oremus 2023). (ii) Capture-Mark-Recapture (CMR) data allowed us to test females’ fidelity to their nesting grounds on a multi-seasonal scale. These data are essentially based on the long-term flipper tag recovery survey conducted at the RP beach since 2006-07 (Barbier et al. 2023). Additional data were collected at the GLS area since the 2016-17 nesting season. (iii) Molecular analyses have contributed to clarify inter-generational connectivity by testing the existence of a gene flow between the reproductive population segments. A tendency for males to show less fidelity to their native breeding grounds than females has been reported in marine turtles (Casale et al. 2013; Beal et al. 2022). Since males rarely come ashore (Fitzsimmons et al. 1997b), direct monitoring of their movements through telemetry and CMR is extremely challenging. In this study, we have therefore included both mitochondrial (mtDNA) and nuclear microsatellite (µsat) markers to assess maternal and bi-parental gene flow between both nesting areas (Fitzsimmons and Limpus 2014). Considering that the RP and the GLS areas are both under the management authority of the Southern Province of New Caledonia, the application of this study is to provide local policymakers with a coherent and prioritized conservation strategy in the context of proximate yet geographically discontinued nesting areas facing heterogeneous threats. 3. Materials and methods 3.1 Study area The ‘Roche Percée’ nesting area (RP) The coastal RP site is a sandy beach located in the bay of Bourail (S°21.61229, E°165.46461), on the west coast of the mainland (Figure 18-C). The breeding ground is composed of thin and dark arenite-type sand, dragged through the Nera River mouth (Allenbach 1998; Limpus et al. 2005b), and vegetation at the rear of the coastline is scarce. The beach of the ‘Roche Percée’ is oriented south-west and is 2.2 km long. At its north end, a second smaller adjacent beach, named ‘Baie des Tortues’ (i.e. Turtle Bay’), is 0.3 km long and is presumably used by the same
RkJQdWJsaXNoZXIy MjE1NDI=