基于Ecopath模型的舟山海域褐菖鲉(Sebastiscus marmoratus)生态容量评估

ASSESSMENT OF ECOLOGICAL CARRYING CAPACITY OF SEBASTISCUSMARMORATUS IN ZHOUSHAN SEA AREA IN THE ECOPATH MODEL

根据2021年渔业资源调查数据构建了含有23个功能组的舟山海域生态系统Ecopath模型,分析了当前舟山海域生态系统总体特征并估算了褐菖鲉在舟山海域的生态容量。结果表明:舟山海域生态系统营养级范围为1.000(浮游植物和有机碎屑)~4.277(鳐类),石首鱼科、虾类和鳐类为舟山海域生态系统中的关键种。碎屑食物链和牧食食物链是舟山海域生态系统主要的食物链。碎屑和浮游植物对食物网的贡献率分别为61.32%和38.69%。始于浮游植物和碎屑的营养传递效率分别是9.34%和10.50%,系统总营养传递效率是9.82%。总初级生产量/总呼吸量为2.26,系统连接指数为0.372,系统杂食性指数为0.222。生态系统总体特征反映了舟山海域生态系统的成熟状态较低,生态系统处于不稳定阶段,容易受到外界环境变化的影响。根据模型估算,当褐菖鲉生物量增加至8.6倍时,褐菖鲉达到生态容量0.00795 t/km2,此时生态系统仍保持平衡,且生态系统总体特征基本稳定。因此,褐菖鲉在舟山海域尚有较大增殖潜力。

The Ecopath model of Zhoushan sea area ecosystem with 23 functional groups was constructed based on the data of the 2021 fishery resources survey,and the general characteristics of the current ecosystem in Zhoushan sea area were analyzed and the ecological capacity of the marbled rockfish Sebastiscus marmoratus in Zhoushan sea area was estimated.Results show that the trophic level of the Zhoushan sea area ecosystem ranged from 1.000(phytoplankton and detritus)to 4.277(stingrays),and Sciaenidae,shrimps,and stingrays were the key species in the Zhoushan sea area ecosystem.The detritus food chain and the grazing food chain were the main food chains in the Zhoushan sea area ecosystem.The contribution of detritus and phytoplankton to the food web was 61.32%and 38.69%,respectively.The nutrient transfer efficiency starting from phytoplankton and detritus was 9.34%and 10.50%,respectively,and the total nutrient transfer efficiency of the system was 9.82%.The total primary production/total respiration was 2.26,the system connectivity index was 0.372,and the system omnivory index was 0.222.The overall characteristics of the ecosystem reflected the low maturity state of the Zhoushan sea area ecosystem,which was in an unstable stage and easily affected by external environmental changes.According to the model estimation,when the biomass of S.marmoratus increased to 8.6 times,S.marmoratus would reach the ecological capacity of 0.00795 t/km2,at which the ecosystem would remain in balance,and the overall characteristics of the ecosystem would be basically stable.Therefore,there is still a large potential for S.marmoratus to proliferate in Zhoushan sea area.