YOU could say Dr Bennan Chen is out of his depth as he feeds a school of hungry mangrove jack, having previously worked with some of the ocean's fastest swimming fish - the yellowtail kingfish.
But he is more than capable of the role in finding ways to improve the survival rates of larval fish.
Dr Chen took up a position with Southern Cross University's National Marine Science Centre in late 2016 to add to his 25 years of marine biology research experience.
Before that he worked with Clean Seas Tuna Ltd and helped reduce deformities in tank-raised fish.
"We solved the yellowtail kingfish jaw deformity and swim bladder inflation issues, improved the larval rearing survival rate and produced good-quality fingerlings for growing each season," he said.
Dr Chen is now working as part of a team on a new project raising captive bred mangrove jack for Clarrie Hall Dam in the Tweed Shire.
"We are running a mangrove jack larval rearing trial at the moment, where we have hatched the eggs and are very busy every day feeding and looking after the fish larvae," he said.
The project is funded by Recreational Fishing Trusts and the NSW Department of Primary Industries.