基于营养通道模型的渤海生态系统结构十年变化比较

Comparative study on the changes of the Bohai Sea ecosystem structure based on Ecopath model between ten years

根据1982年和1992年渤海渔业资源和生态环境调查数据,应用EwE建模软件,构建了两个时期的营养通道模型,并比较分析了10a间渤海生态系统结构以及渔业资源的变化。模型包含鳀、黄鲫、蓝点马鲛、其它中上层鱼类、小黄鱼、花鲈、其它底层鱼类、底栖鱼类、浮游动物、浮游植物、碎屑等17个功能群,基本覆盖了渤海生态系统能量流动的途径。分析结果表明,1992年渤海生态系统的总生物量比1982年有所下降;小型中上层鱼类成为渔业资源的主要成分,其生物量较1982年明显增加;由于低营养级层次渔获物数量的增加,渔获物平均营养级有所下降。从系统规模看1982年大于1992年。1982年到1992年的十年间,引起渤海生态系统结构变化的主要原因是初级生产力的变化以及捕捞因素。1982年与1992年渤海生态系统均处于不成熟的发育期,仍有较高的剩余生产量有待利用,因此渔业资源恢复的物质基础是有保证的。

The study was based on the investigations of fishery resources and environment of the Bohai Sea in 1982 and 1992. Using the EwE modeling software, the mass-balance models of the Bohai Sea ecosystem during the two periods were constructed. Based on the two models, the changes of the Bohai Sea ecosystem structure and fishery resources between ten years were compared and analyzed. The models included 17 functional groups covering the main trophic flow of the BohaiSea ecosystem, which were Japanese anchovy, Scaly hairfin anchovy, Japanese Spanish mackerel, other pelagic fishes, small yellow croaker, seabass, benthic fishes, other demersal fishes, zooplankton, phytoplankton, detritus, etc. The results indicated that the total biomass of 1992 was lower than that of 1982, and small sized pelagic fishes have become the maincomponents of the fishery resources in the Bohai Sea in 1992, and the proportion was obviously higher than that in 1982. Since the catch of lower trophic level fishes increased in 1992, the mean trophic level of catch declined. The Bohai Sea ecosystem in 1982 and 1992 were both in developmental stage, and the system scale in 1982 was greater than that in 1992.From 1982 to 1992, the changes of the Bohai Sea ecosystem structure were mainly due to the decrease of primary production and increase of fishing pressure. Since there was high surplus production, the recovery of depleted fishery stocks andincrease of fishery resources may be possible and high potential if the rational conservation measures were applied.