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.

The potential for reef line fishing to significantly affect the productivity of targeted species or impact on other reef species is poorly understood. Understanding the distribution, intensity, and effects of reef line fishing will be essential for successful management of both fishing and other recreational and commercial activities in the GBR region, as well as for conservation of the GBR ecosystem. Further, there is an immediate need for careful investigation of potential management strategies and their impacts on economic, social and biological and conservation values of the GBR and its use.

Since 1993, the commercial Reef Line Fishery has been undergoing some change as a result of the development of lucrative export markets for live reef fish for consumption. The value added to the commercial catch as a result of high market values for live fish (landing prices for live coral trout peaked in August 1996 at $45/kg) has the potential to increase incentives for previously inactive endorsements (of which there are approximately 1300-1400) to be activated in the line fishery, with a resultant increase in effective commercial fishing effort. An indirect indicator that this may be happening already is a 2-3 fold increase in the market value of reef line endorsements over the past 12-18 months, the acquisition of second and third vessels by some operators, and purchases of large, purpose built or re-fitted vessels for the live fish sector of the fishery. There is also considerable potential for increased recreational fishing pressure simply as a result of population growth and increased tourism. These factors, combined with the dearth of historical information about the fishery or its main target species present great problems for planning appropriate management strategies of the fishery and the Great Barrier reef Marine Park.

In "Research Needs and Priorities" (1996), the QFMA flagged key topics for research related to the Reef Line Fishery which included: Appraise management measures for the sustainable use of reef fish; Determine an effective mix of measure for reef fish management planning, including fishery dependent and independent monitoring; Determination of the size of stocks of common coral trout; Determination of the proportion of blue-spot trout in the reef line catch; and Assess regional catch rates of red-throat sweetlip. The ELF Project will produce results of direct relevance to these and other needs, and in so doing will contribute greatly to management-relevant information in a relatively short period (3-5 years).