摘要
根据1991年和2000年冬季在黄海中南部和东海中北部海域进行的底拖网调查资料,对黄、东海底层鱼类群落的资源状况、重要种类的生态优势度与结构、多样性及其空间分布格局等方面的动态变化进行了分析。结果表明,生物量指数明显下降,个体小型化使生物资源密度显著上升;重要种类成分发生演替,优势度有较大变化;物种丰富度指数(D)下降极其显著,Shannon-Wiener多样度指数(H′)也有所下降,但不显著。
Based on the bottom trawl surveys in the Yellow Sea and East China Sea in winter 1991 and 2000, the yearly variations of demersal fish's abundance, community structure and dominance of important species, diversity and its distribution were analyzed. The results indicate that the number of fish species caught varied between both surveys, 185 species were found in 1991, and 178 species in 2000. The abundance decreased apparently by 46.7% in 2000(39.188 kg·h^(-1)) than 1991 (73. 539 kg·h^(-1)). The major species of those are Navodon septentrionalis, Trichiurus haumala, Pampus argenteus, Scomberomorus niphonius, Argyrosomus argentatus, Muraenesox cinereus and Ilisha elongata, among them Navodon septentrionalis declined most significantly at the magnitude of 99.6% in abundance. The mean weight of all caught individuals in 2000(7.4g·ind^(-1))decreased by 89.0% in contrast to 1991 (67.4 g·ind^(-1)). In general, the higher trophic level of fish is, the more significantly the mean weight of bodies declines. The size became smaller, which caused the density to increase dramatically up 3.9 times in 2000(5322 ind·h^(-1)) than 1991 (1091 ind·h^(-1)). The species of fish having index of relative importance(IRI)abundance more than 1000 is defined as a dominant species in the community. Both Trichiurus haumala and Engraulis japonicus are dominant in 2000 and 1991, Trichiurus haumala was first in 1991, but Engraulis japonicus became first in 2000. The fish with IRI values of 100 to 1000 is considered as major species, a total of 12 species in 1991, which were Trachuras japonicas, Navodon septentrionalis, Pampus argenteas, Pseudosciaena polyactis, Lepidotrigla microptera, Priacanthas macracanthus, Collichthys niveatas, Lophias litulon, Lagocephalas gloveri, Setipinna taty, Argyrosomas argentatas and Thamnaconus hypargyreas in order of IRI, but a total of 11 species in 2000, which are Acropoma japonicum, Pseudosciaena polyactis, Champsodon snyderi, Apogonichthys lineatas, Trachuras japonicas, Pampus argenteus, Benthosema pterotum, Synagrops japonicus, Collichthys niveatas, Setipinna taty and Pneumatophorus japonicus. During 9 years, there was the succession on important components of fish community, its dominance greatly changed, the species richness index (D) declines obviously (P<0.001) at the magnitude of 33.6%, the Shannon-Wiener index (H') as well 8.9%, but not obviously (P>0.05), and the species evenness index (J')varies less. Through two surveys, the distribution pattern of three diversity indexes, which are species richness index (D), Shannon-Wiener index(H'), species evenness index(J'), are generally lower in the north, higher in the south, smaller in the west and larger in the east in the Yellow Sea and the East China Sea.
出处
《水产学报》
CAS
CSCD
北大核心
2004年第1期29-34,共6页
Journal of Fisheries of China
基金
国家重点基础研究项目(G1999043712)
