The Western Bass Strait Trawl Fishery Assessment Program was the first extensive study of the demersal trawl fishery in western Bass Strait. The study provided biological and fishery information on 11 commercially important species. All data presented here have been used extensively in the assessment of South East Fishery, primarily as reports to the Demersal and Pelagic Fisheries Research Group and Orange Roughy Workshops. This study has also provided the baseline data for subsequent assessment of the fishery through the South East Fishery Assessment Group (SEF AG).

The trawl fishery in western Bass Strait expanded rapidly during the 1980s mostly in response to the discovery of substantial orange roughy aggregations in 1986/87. Landings in main ports reached 10,000 tonnes by the late 1980s with over 3000 tonnes taken from the study area. Apart from orange roughy, blue grenadier was the major species. The catch of blue grenadier increased from about 400 tonnes (partial weight) in the mid 1980s to over 700 tonnes (partial weight) by the early 1990s. Blue and spotted warehou, were the other major species in terms of weight. The annual catches of king dory and ling increased between 1986 and 1993, whereas those of gemfish and jackass morwong declined. The catch of ocean perch, and silver and mirror dory was low, less than 20 tonnes in all years.

The study combined a stratified random trawl survey in depths from 100 to 1200 m with extensive sampling of commercial landings. The trawl survey of western Bass Strait was conducted between 1987 and 1989 was undertaken on generally smooth trawlable ground. Orange roughy, blue grenadier and warty oreo were consistently the dominant species. Biomass estimates for ling, ocean perch and gemfish were low in all surveys. Spotted warehou abundance was distinctly seasonal being relatively high only during winter. Survey catches of blue warehou were particularly low and the biomass estimates for this species were unreliable. Biomass estimates for king dory and spiky oreo varied between surveys but they were moderately abundant. The study species contributed substantially to the total demersal fish biomass in western Bass Strait.