Stock Assessment of Queensland East Coast black jewfish (Protonibea diacanthus), Australia, with data to December 2021

Abstract

Black jewfish (Protonibea diacanthus) are caught on the east coast of Queensland by commercial, recreational, charter and Indigenous fishers. The fishery is focused around Central Queensland, and has recently experienced a large shift in commercial effort and gear types. The species was historically considered a byproduct species within the inshore net fishery, but has now become a targeted line caught species.
In Australia, black jewfish are found from Exmouth Gulf in Western Australia, north and east across Northern Australia, to the east coast of Queensland. Research suggests that stocks cover hundreds of kilometres.
This is the first stock assessment of the Queensland East Coast stock. The stock assessment was conducted on calendar years and included input data through to December 2021.
Eight model scenarios were run, covering different combinations of recreational dead catch and population steepness (productivity parameter). Base case (preferred) scenario results suggested that biomass declined gradually from the 1940s to the 1980s and has increased slightly since then. The spawning stock level at the beginning of 2022 for base-case scenarios was estimated to be between 56% and 99% with a median estimate of 79%. The estimates from other scenarios ranged from 80% to 92%. Despite high uncertainty around the exact level of biomass, the model outputs indicate that the biomass is probably at or above the target reference point of 60% unfished biomass.