This project uses genetic parentage analysis, biophysical modelling and information on coral trout larval behaviour to determine patterns of recruitment of coral trout larvae within and among inshore and offshore reefs in the southern Great Barrier Reef. The overall goal of this project will be to assess larval dispersal patterns, demographic connectivity and levels of recruitment subsidies from green zones at a regional scale. Tasks include: 1. Collect tissue samples from adult and juvenile coral trout, develop a new set of hyper-variable microsatellite markers, conduct DNA genotyping analyses of all samples, carry out genetic parentage analysis to examine parent-offspring relationships. 2. Refine the existing biophysical model and assess likely origins of larvae at key recruitment hot spots in the region. 3. Undertake demographic metapopulation analyses using dispersal distances and trajectories derived from this study and available demographic data (growth, natural mortality, fishing mortality) to evaluate long-term persistence of green zone and blue zone populations under different levels of fishing pressure and habitat condition.

This project is providing a direct assessment of the ecological effects of multiple-use zoning on inshore reefs of the GBRMP. Underwater visual census (UVC) monitoring of fish and benthic communities is being carried out at 50 no-take marine reserve (green zone) sites and at 50 sites that have remained open to fishing within the Palm, Magnetic, Whitsunday and Keppel Island groups. Long-term monitoring surveys are providing information on: 1. The effects of no-take marine reserves on populations of both species that are fished and other non-fished species. 2. Variations in structure of fish communities due to the reserves and natural disturbances. 3. Structure and dynamics of marine species on the sea bed. 4. Coral health, bleaching, incidence and severity of coral disease and coral predators. 5. Temporal monitoring of the relative number of fishing lines recorded at each site will be used to assess the distribution of fishing effort and provide information on the levels of non-compliance with zoning regulations.