Contrasting trajectories of crustacean stocks in coastal China: impacts of fishing intensification vs. enhancement initiatives
摘要
The explosive growth of marine fishing capacity over recent decades has positioned China as the world’s largest marine fisheries producer, while simultaneously inducing profound structural and functional shifts in coastal fishery ecosystems. China’s coastal waters represent a global biodiversity hotspot for crustaceans, supporting numerous crustacean species with ecological importance and economic value. However, effective management of crustacean resources remains inadequate due to insufficient stock assessments. This study employed the Catch-Maximum Sustainable Yield (CMSY + +) method to estimate historical exploitation dynamics and current stock status for six economically critical marine crustaceans in China. The rapid expansion of fishing efforts since the 1980s-1990s emerged as the primary factor driving resource depletion in Acetes spp., Trachypenaeus curvirostris, and Charybdis spp. Conversely, stock enhancement and releasing initiatives have demonstrated remarkable efficacy in restoring populations of Penaeus spp., Portunus spp., and Scylla spp. By 2023, all assessed species except Charybdis spp. maintained healthy biomass levels with sustainable fishing mortality. Integrated Schaefer model simulations revealed that Charybdis spp. populations exhibit rapid recovery following fishing pressure reduction. This suggests that controlled harvest intensity may represent the most effective pathway for fishery rebuilding, which will improve fishery stock structure and bring more catches.