Anthropogenic factors such as climate change and overexploitation of fisheries present challenges for coral reefs and the biodiversity they support. This environmental degradation is particularly concerning to communities in Fiji, which rely heavily on reef ecosystems for sustenance. To combat the ecological stressors reef ecosystems face, governments establish Marine Protected Areas (MPAs) that prohibit practices such as fishing and coral harvesting.
A new MPA has been recommended in the waters of Fiji based, in part, on patterns of genetic diversity and connectivity of the three-spotted wrasse (Halichoeres trimaculatus), a commercially-fished species. This recommendation was based on specimens collected in 2014. However, there is a common wrasse larval pool that serves as an annual source for all the populations around Fiji. It is assumed that the annual dispersal of wrasse larvae is randomized throughout Fijian waters, and individual locations exhibit similar levels of genetic diversity across time. If this is not the case, then the MPA placement in Fiji must be reconsidered.
This project explores the temporal pattern of genetic diversity and connectivity of the three-spotted wrasse by looking at the mitochondrial control region in 78 specimens collected across five summer field seasons, from 2011 to 2016.
This study provides insight into the temporal distribution of genetic diversity, and therefore informs sampling design for molecular ecology studies. Preliminary results indicate that the mitochondrial control region haplotypes present across the five sampling years are found in 2014. This indicates that the annual dispersal of the wrasse larvae is randomized, and that a single year’s data can be reliably used to make generalizations about population genetic diversity and connectivity.