Growth, mortality, movements and nursery habitats of red-legged banana prawns (Penaeus indicus) in the Joseph Bonaparte Gulf. Final Report to FRDC for project 1997/105

This project has contributed to the ecologically sustainable management of the Northern Prawn Fishery (NPF) by providing information on the status of red-legged banana prawn stocks and the nursery habitats that support this fishery. It has achieved these outcomes by firstly completing detailed tagging studies to obtain robust estimates of growth and mortality for red-legged banana prawns. These estimates enabled per-recruit models for red-legged prawns to be revised and for the sustainability of the current fishing patterns to be assessed. The levels of estimated recruitment to the fishery are much lower than previously estimated and therefore the stocks may be more vulnerable to over-fishing than past assessments suggested. Secondly, broad-scale surveys across the inshore areas of the Joseph Bonaparte Gulf established that juvenile red-legged banana prawns are found in small, mangrove-lined creeks in the estuaries located 100 to 200 km south-east of the fishery (Fitzmaurice/Victoria Rivers to Cambridge Gulf). This means that changes in land-use that affect coastal habitats or water flow (e.g. the Ord River Stage II development) may affect the juvenile stages and the emigration of juveniles into the fishery