Black jewfish research to identify knowledge gaps
A collaborative study between the Department of Primary Industry and Resources (DPIR), Charles Darwin University and the Australian Institute of Marine Science is investigating black jewfish populations and environmental factors to ensure future sustainability in the Northern Territory (NT).
Regarded as one of the NT’s most popular reef fish, black jewfish (Protonibea diacanthus) is commonly found in cloudy coastal waters, tidal rivers and estuaries. Black jewfish grow extremely fast, reaching almost 60 cm in their first year and 90 cm in their second, with a lifespan of up to 13 years.
“Black jewfish are highly sought by commercial and recreational fishers and have been heavily over fished in recent years in the Darwin area due their aggregating nature and susceptibility to barotrauma” said Thor Saunders, DPIR Principal Research Scientist.
Although over fishing black jewfish has been on the radar for a few years, this study will include environmental data to support a more dynamic strategy based on productivity, population and size structures.
“The study aims to establish the quantity and size of the current black jewfish population but also to investigate the biology of the fish and how they respond to changes in the environment, for example how they adapt during the rainy season,” Saunders said.
The research team is specifically evaluating their age, size, sex, weight and health to get a better idea on how the environment impacts their behaviour and diet.
The study joins forces with fishers, both commercial and recreational, at four sites along the NT’s coastlines, including the Tiwi Islands.
Filling the knowledge gaps will ensure sustainable black jewfish fishing practices in the NT while protecting and rebuilding the population.
The project is led by Charles Darwin University post-doctoral research fellow, Dr Jo Randall, and is