南海北部大陆架海洋生态系统Ecopath模型的应用与分析

过度捕捞和环境恶化导致渔业资源和海洋生态系统逆向发展。采用EwE5.1软件,对南海北部大陆架建立Ecopath(生态通道模型)模型。通过各级流量、生物量、生产量、捕捞量、系统总流量以及生态位和混和营养效应等方面的分析,得出营养流通主要有2种途径,肉食鱼类间饵料竞争非常激烈,低值鱼类间具相似的捕食压力,顶级捕食者对大部分鱼类负效应不明显。系统受过度捕捞渔业影响很大,并存在营养级I利用效率低和渔业资源小型化、低值化等不稳定的幼态特征。

Establishment and Analysis of the Ecopath Model of the Ecosystem in the Northern Continental Shelf of South China Sea

Overfishing and envirornmental deterioration have caused fishery resources and ocean ecosystems to develope adversely.The Ecopath model for the northern continental shelf of South China Sea was established by using software EwE 5.1.By analyzing the throughput,biomass,production,catch yields on each trophic level, and total system throughput,niches and mixed trophic impacts,etc.,it has been found that there are two main trophic circulation pathways in the ecosystem.The piscivorous fishes have drastic prey competions,lower-valued fishes have greater predator stresses;the negative effects of the apex predators on most fishes are not apparent.The ecosystem appears to be a young weak one caused by overfishing,with small and low-valued fishes dominated and low ecotrophic efficiency for trophic level I.