Tools and criteria for ensuring estuarine stock enhancement programs maximise benefits and minimise impacts

Abstract

New South Wales (NSW) is the first jurisdiction in Australia to approve and implement an ongoing marine stock enhancement program. As part of the development and consent process an Environmental Impact Statement (EIS) was prepared, and a management strategy developed to govern the activity in estuaries and control for risks outlined in the EIS. Initially, the EIS developed and used novel tools and criteria to determine which of 158 NSW estuaries were most appropriate to achieve the program’s goals for the seven recreationally-targeted species (4 fish, 2 crab and 1 prawn species). Estuaries within three release regions were selected and ranked using a multi-criteria analysis of 20 factors considered important to the success of stock enhancement. Estimation of the trophic impact of released species and estimates of the productivity of the selected estuaries were used to determine release rates at various sizes for the target species. Criteria were established to: (1) ensure best practice broodstock management and genetic quality of released recruits; (2) minimise disease risk through stock enhancement; and, (3) maximise social and economic benefits from stock enhancement. These tools and criteria fed into the risk assessment in the EIS and guided further controls outlined in the management arrangements for the program. In this paper, we outline this novel approach to development and assessment of stock enhancement activities. We discuss the potential application of this framework to marine stock enhancement activities in other jurisdictions.