Research progress and prospects on benefit assessment of marine ranching

Marine ranching is a key strategy for the transformation and upgrading of China's marine fisheries, aiming at promoting the proliferation of marine fisheries resources and ecological environment restoration through artificial intervention. Artificial reefs and stock enhancement are important ways for the construction of marine ranching. Artificial reefs enhance marine habitats, thereby providing niches conducive to the habitation of fish species, while stock enhancement initiatives serve to directly supplement populations of specific marine species. This paper reviews the developmental trajectory, current construction status and benefit evaluation methodologies of marine ranching. It provides an analysis of the underwater physical conditions, hydrodynamic effects, scale effects, and fisheries propagation effects associated with artificial reefs, emphasizing on the importance of their scientific deployment. The paper also summarizes methods for assessing the efficacy of stock enhancement, encompassing mark-recapture techniques, statistical analyses and model-based assessments. Although China has made significant progress in these areas, challenges persist, such as the unclear relationship between the scale of artificial reef construction and ecological benefits, the necessity for enhanced precision in evaluating the outcomes of stock enhancement, and the absence of sophisticated quantitative assessment models. Thus, the paper proposes future research directions and recommendations, including the enhancement of evaluative indicator systems, the intensification of technological innovation, the development of robust quantitative assessment models, and the strengthening of policy and managerial guidance, so as to promote the progression of marine ranching research and practice, thereby realize the sustainable utilization of marine fishery resources and the achievement of marine ecological balance.