北部湾生态通道模型和保护区效应的模拟

Ecopath Model and Its Implication in Modelling the Effects of Spatial Closure in the Beibu Gulf Ecosystem

作为一种有效的养护海洋资源和生态系统的工具,海洋保护区正逐步得到世界各国的普遍认同。在20世纪90年代EwE模型的基础上,以20 a为周期,利用空间化模块Ecospace模拟了不同的管理情景(禁渔、伏季休渔、共同渔区、<30 m沿岸水域)对北部湾海洋生态系统功能组的生物量和渔获量的影响。结果表明,缺乏管理和渔民合作的禁渔制度和伏季休渔制度对资源的养护作用不显著,大型鱼类和真鲨类等高营养级生物量继续衰退。在北部湾沿岸和中南部海域设立大型的非渔业活动区都可有效地降低捕捞强度和恢复渔业资源,提高渔获质量。研究结果表明,海洋保护区对栖息地养护和渔业管理上有重要作用。从北部湾渔业管理的角度来看,将30 m等深线内的沿岸水域划为非渔业保护区更有利于生态系统的养护和渔业资源的恢复。

Marine Protected Areas （MPAs） are increasingly being recognized as an alternative management tool for conserving marine resources and ecosystems. Based on the 1990s Ecopath with Ecosim model in the Beibu Gulf, we used Ecospace routine too forecast resources and fishery responses to different MPAs deployed （spatial closures system, closed season, common fishing zone and costal area with depth less than 30 m） in the Gulf of Beibu marine ecosystem over a 20-year period. Simulations suggested that current trawl closures and closed season used in the Beibu Gulf fisheries, appear to be minimally benefits without the cooperation of fishers and costly administrative, the biomass of top predator groups, such as top demersal and pelagic fishes and elasmobranches would be decreased continuously during the simulation period. Both ＂no-take zone＂, coastal closures and common fishing zone closures can drastic reductions in fishing efforts and restoring declined fisheries resources, especially for high value fishes. This study supports predictions that MPAs can play a key role in the conservation of habitats and management of a fishery. It is suggested that for the purpose of fishery managements in the gulf, the costal areas with depth less than 30 m as ＂no take zone＂ may be an effective management tactic to conserve ecosystems and restore fisheries resources.