Stock Assessment of stout whiting (Sillago robusta) in eastern Australia

Abstract

This assessment describes the commercial stout whiting (Sillago robusta) fishery operation along Australia’s east coast between Sandy Cape (24.7 0S) in Queensland and 32 0S in New South Wales. The stock assessment builds on previous assessments and uses an age-structured population model with a yearly time step and length-based selectivity. The annual data inputs included total harvest, standardised catch rates, length structures and age structures. The model used data from 1945 to 2020.

The assessment suggested the stock in 2020 was at around 42 per cent unfished spawning biomass. The recommended biological catch was estimated at 2018 t for all fishing sectors and waters (this included bycatch from the Queensland prawn trawl fishery). This initial catch estimate aims to allow the stock to rebuild to the target 60 per cent spawning biomass by 2040. Smaller harvests are estimated at first to be taken in early years, which increase through time as the fish population builds higher.