There is an urgent need for fishery independent data to improve and calibrate abundance measures of tropical demersal finfish species derived from commercial catch data that underpins quota setting processes. More specifically, species specific catchability measures are required for the main target species in the NDSF and other similar fisheries, to determine how the landed catch of each species relates to the overall biomass of the stock in the fishery region. At present the limited understanding of the catchability relationship is leading to the management need to set conservative risk-averse effort quota levels which are allegedly constraining the development of this fishery. This project will use ‘baited remote underwater video’ (BRUVs) and research vessel trawl surveys to directly assess the size composition and abundance of relevant fish species in trap and line fishing areas to generate the necessary data on catchability for each fishing method. The trawl survey derived size composition data for target species will also be used to meet the need for unbiased population samples in the stock assessment models, and will be designed to be replicated in the future (at an appropriate temporal scale). The successful completion of this project will meet the requirement for more precision in the stock size estimates and therefore meet industry’s requirement for an optimal and possibly less constraining approach to effort quota setting in the NDSF and similar fisheries.