Data from: Connectivity in grey reef sharks (Carcharhinus amblyrhynchos) determined using empirical and simulated genetic data

Grey reef sharks (Carcharhinus amblyrhynchos) can be one of the
numerically dominant high order predators on pristine coral reefs, yet
their numbers have declined even in the highly regulated Australian Great
Barrier Reef (GBR) Marine Park. Knowledge of both large scale and fine
scale genetic connectivity of grey reef sharks is essential for their
effective management, but no genetic data are yet available. We
investigated grey reef shark genetic structure in the GBR across a 1200 km
latitudinal gradient, comparing empirical data with models simulating
different levels of migration. The empirical data did not reveal any
genetic structuring along the entire latitudinal gradient sampled,
suggesting regular widespread dispersal and gene flow of the species
throughout most of the GBR. Our simulated datasets indicate that even with
substantial migrations (up to 25% of individuals migrating between
neighboring reefs) both large scale genetic structure and genotypic
spatial autocorrelation at the reef scale were maintained. We suggest that
present migration rates therefore exceed this level. These findings have
important implications regarding the effectiveness of networks of
spatially discontinuous Marine Protected Areas to protect reef sharks.