Jiaozhou Bay, situated at latitude 35°38′N～36°18′N, longitude 120°04′E～120°23′E, is a typical semi-enclosed shallow bay. The number of species in Jiaozhou Bay is very rich, and some species such as Ruditapes philippinrium, Terebellides stroemii, Sternospis scutata, are especially abundant.This paper reports the current condition of species diversity of macrobenthic fauna in Jiaozhou Bay (Qingdao, China). Study materials were collected once every three months from 15 cruises of investigation carried out in February, 1998 to November, 2001.
In analyzing the data, the Shannon-Wiener index, species evenness and richness indices are used to study the distributional trends of community structure, the distributional trends of species assemblages, dominant species and abundance of macrobenthic fauna in Jiaozhou Bay.
A total of 322 species macrobenthic animals were obtained from Jiaozhou Bay, of which 133 species belong to 44 families in Polychaeta, while 92 species belong to 42 families in Crustacea. Only 14 species of Echinodermata were found. Forty-seven species were ranked as dominant species of which Ruditapes philippinarum, Sthenolepis japonica, Natatolana japonensis are among the most dominant of each group. The average number of species was about 8～26 per sample station, the lowest number, 8 species, was found in Station No.7, the maximum number, 26 species, was found in Station No.3. The total number of individuals in samples taken in different months showed great variation because of great variation in the number of short life span species.
There was great difference of Shannon-Wiener index between each sample, the highest was 4.77, recorded in Nov. 2001 from Station No. 8, the lowest was 0.95, recorded in Aug. 2001 from Station No. 9. Stations No. 4, 6 had higher Shannon-Wiener indices and species richness indices than other stations. Both the number of species, the Shannon-Wiener indices and species richness indices were lower in Stations No.7 and 9 than in other stations, because they were situated at the areas with rapid current and with coarse sandy bottom. Although Station No. 3 has high species richness and high Shannon-Wiener index, it has the lowest Pielou evenness index because it is located near the Ruditapes philippinarum culture area, where high abundance of clam caused lowering of the evenness index. Most stations had higher Pielou evenness indices in winter than in spring, because spring is the season when some species grow fast, mature, reproduce and thus increase in abundance.
Based on analysis of data, it is revealed that the number of species and its abundance have great effect on biodiversity, some environmental factors such as temperature, salinity and primary productivity are closely interrelated with biodiversity. Anthropogenic factors causing pollution and over-exploitation have adverse effect on biodiversity. In order to find out the best way to enhance and protect marine living resources, the impact of human activities relationship on biodiversity of macrobenthos in Jiaozhou Bay should be studied further.