Ecosystem stability of marine ranching and its response to disturbance: research status, issues, and suggestions

Marine ranching is a fishing model based on the principle of ecosystem. It constructs or repairs habitats for marine organisms to reproduce, grow, feed or keep safe in specific sea areas through constructing artificial reefs and stock enhancement, proliferates and maintains fishery resources, improves the marine ecological environment, and achieves sustainable utilization of fishery resources. In recent years, while the marine ranching is developing rapidly, it is also facing many challenges, which greatly restricts its healthy development. In the process of constructing marine ranching, construction of habitat like artificial reefs, as well as stock enhancement, has played important roles in resource conservation and aquatic product output. They are also considered key to improve the marine ecological environment and achieve sustainable utilization of biological resources. However, the placement of artificial reefs and stock enhancement in marine ranching can bring a series of physical, chemical, and biological disturbances to the ecosystem. The effects and manifestations of these artificial disturbances are diverse, and will they become the expected gain interference? Will inappropriate habitat construction or excessive stock enhancement reduce ecological carrying capacity, cause habitat degradation, and alter the composition of communities and carbon cycling patterns? The current basic theories on habitat construction and stock enhancement are weak, and the stability and anti-interference ability of ecosystems are unclear. Especially, little is known about the structure and functional implementation process of small-scale marine ranching ecosystems, as well as their ecological carrying capacity. Therefore, it is urgent to carry out theoretical verification and quantitative research on the environmental effects of artificial reefs and other habitats, as well as the resource replenishment effects of stock enhancement, in order to fully understand the duality of these artificial disturbances. This article digs into over 90 relevant papers and briefly reviews the domestic and international advances on the effects of constructing artificial reef habitats in aspects of hydrodynamic characteristics, migration of biogenic elements, mechanism of community assembly, and ecosystem stability assessment. Emphasis was placed on the complexity and dynamics of the small-scale marine ranching ecosystem structure, with focus on how the layout of artificial reefs affects the evolution of the hydrodynamic environment, sediment, and biogenic elements in the ranching areas, as well as the mechanisms of species coexistence under artificial disturbances such as stock enhancement. Focusing on key issues such as the stability and anti-interference ability of marine ranching ecosystems, this article explores the shortcomings and development directions of current researches from four aspects: hydrodynamic driving conditions, biogenic elements characterization, community assembly, and ecosystem health assessment. This provides a reference basis for the construction of artificial reefs, seaweed beds, and other ecological habitats in marine ranching, as well as the optimization of resource restoration models.