渤海鱼类群落结构特征的研究

STUDY ON CHARACTERISTICS OF FISH COMMUNITY STRUCTURE IN BOHAI SEA

根据1982-1985年和1992年8月-1993年6月间渤海渔业增殖生态学调查所得的1090网次定量资料，运用数理统计的方法，分析鱼类群落结构多样性综合指标的变化特征。结果表明，在1982－1985年间渤海鱼类鱼种数为119种，其中暖温种居首位，占57．98％；暖水种欢之，占28．57％；冷温种种数最少，占13．45％。群落结构的季节变化规律呈现单周期型，10月份鱼种数最多，达83种；2月份仅为对种。NED和BED最高在9月份，分别为170．58千尾/km2和1．71t／km2；3月份则为最低期，两指标分别为5473尾/km2和166．68kg/km2。鱼类群落由4种优势种组成：黄鲫、黑鳃梅童鱼、和小黄鱼等。IRI值50－1000为常见种，计27种，与优势种一起构成渤海鱼类群落重要成分。累计NED为52．667千尾/km2，占全部鱼种的97．83％；BED为719．677kg/km2，占90．86％。在1992－1993年间，鱼种数、NED和BED分别下降38．66％、35．46％和46．10％；上升为首位优势种，NED占51．97％，BED占38．49％。渤海鱼类群落持续性较高（ISTR为0．8105），并具有年间降低的趋势。

Study on the characteristics of fish community structure, based on data from quantitative survey of 1090 hauls by means of demersal trawls during1982 to 1985 and 1992 to 1993 in the Bohai Sea, showed that 119 fishes formthe community units belong to a part of the Yellow Sea system and are comprisedof warm-temperate (57. 98%), and warm-water (28. 57%) and cold-temperate(13. 45%) species. The community diversity integrated indexes, such as speciesnumber, NED and BED, were single cycle seasonal fluctuations with maximumspecies number of 83 in October, minimum of 37 in February. The minimum ofNED and BED were 5 473 individuals and 166. 68 kilogram per square meter,maximum of 170. 58×103 individuals and 1.71 tons per square meter, respectively.With regard to the index of relative importance (IRI) (Pianka, 1971), fourspecies, half mouthed anchovies, SetiPinna taty, croakers, Collichthys niveatus,japanese anchovies, Engraulis japonicus, and small yellow croakers, Pseudosciaenapolyactics, were dominant components, and some other 27 regular componentswith IRI values of 50 to 1 000, along with the 5 species above were considered asimportant species in the Bohai Sea community during 1982 to 1985, comprising97. 83% in NED and 90. 86% in BED. However, using of data from 1992 to1993, japanese anchovies, Engraulis japonicus, is now predominant with 51. 97%in NED and 38.49% in BED, partly due to decline in persistence and stability ofthe community.