Closing the gap: mixed stock analysis of three foraging populations of green turtles (Chelonia mydas) on the Great Barrier Reef

PeerJ

Johanna Leonhardt¹  Mark Hamann²  Lynne van Herwerden²  Julia Hazel³  Graham Burgess⁴  Ellen Ariel⁴  Karina Jones⁴  Ian Bell⁵  Michael Jensen⁶ 

[1] ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia;Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville, Queensland, Australia;Centre for Tropical Water and Aquatic Ecosystem Research, James Cook University, Townsville, Queensland, Australia;College of Public Health, Medical and Veterinary Sciences, James Cook University of North Queensland,Townsville, Australia;Department of Environment and Science, Queensland Government, Townsville, Queensland, Australia;Marine Mammal and Turtle Division, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, CA, USA;

关键词: Mixed stock analysis;    Marine turtle;    Spatial ecology;    Genetics;    Chelonia mydas;    Mitochondrial DNA;   

DOI  :  10.7717/peerj.5651

来源: DOAJ

【 摘 要 】

A solid understanding of the spatial ecology of green turtles (Chelonia mydas) is fundamental to their effective conservation. Yet this species, like many marine migratory species, is challenging to monitor and manage because they utilise a variety of habitats that span wide spatio-temporal scales. To further elucidate the connectivity between green turtle rookeries and foraging populations, we sequenced the mtDNA control region of 278 turtles across three foraging sites from the northern Great Barrier Reef (GBR) spanning more than 330 km: Cockle Bay, Green Island and Low Isles. This was performed with a newly developed assay, which targets a longer fragment of mtDNA than previous studies. We used a mixed stock analysis (MSA), which utilises genetic data to estimate the relative proportion of genetically distinct breeding populations found at a given foraging ground. Haplotype and nucleotide diversity was also assessed. A total of 35 haplotypes were identified across all sites, 13 of which had not been found previously in any rookery. The MSA showed that the northern GBR (nGBR), Coral Sea (CS), southern GBR (sGBR) and New Caledonia (NC) stocks supplied the bulk of the turtles at all three sites, with small contributions from other rookeries in the region. Stock contribution shifted gradually from north to south, although sGBR/CS stock dominated at all three sites. The major change in composition occured between Cockle Bay and Low Isles. Our findings, together with other recent studies in this field, show that stock composition shifts with latitude as a natural progression along a coastal gradient. This phenomenon is likely to be the result of ocean currents influencing both post-hatchling dispersal and subsequent juvenile recruitment to diverse coastal foraging sites.

【 授权许可】

Unknown