Barramundi origins : Determining the contribution of stocking to the barramundi catch on Queensland’s east coast

Abstract

Researchers from Queensland’s Department of Agriculture and Fisheries, James Cook University, and the University of Western Australia tested a range of otolith-based and genetic methods to identify hatchery-born from wild-born Barramundi. The project took place in the Dry Tropics region, where extensive historical and ongoing impoundment stocking (release of hatchery-born Barramundi into freshwater bodies) may be contributing to the downstream wild-capture marine and estuarine fishery. Fish samples were collected from the commercial and recreational wild-capture marine and estuarine fishery in 2019 and 2020, following the major Townsville floods in February 2019. The team identified a cost-effective means of using trace elements in fish otoliths to reliably distinguish hatchery-origin from wild-origin fish, measure the contribution of stocked fish to the wild population, and assess the sustainability of the wild-capture fishery.