Shrimp community structure and its relationships with environmental factors in Haizhou Bay and adjacent waters in spring

Abstract

Based on the data collected from the bottom trawl surveys in Haizhou Bay and adjacent waters in March and May 2011, the community structure and its relationships with environmental factors for the shrimp assemblage in spring were examined using relative importance indices, ecological diversity indices and multivariate statistical analysis. A total of 21 shrimp species were captured, belonging to 8 families, 15 genera. The relative abundance of shrimp of all stations was 161–28,950g/h in March and 19–28,890g/h in May with the mean values of 3917g/h in March and 3089g/h in May. The relative abundance of shrimp generally presented a decreasing trend from the east to the west in the surveyed area in spring. The dominant species were Metapenaeopsis dalei, Crangon affinis, and Alpheus japonicus in March, accounting for 84.5% of the total biomass of shrimp. The common species were Eualus sinensis, Latreutes anoplonyx, Palaemon gravieri, Alpheus disinguendus and Latreutes planirostris in March, which accounted for 14.1% of the total biomass of shrimp. The dominant species were M. dalei and C. affinis in May, occupying 87.0% of the total biomass of shrimp in May. The common species were Trachysalambria curvirostris, E. sinensis and A. japonicus in May, which occupied 7.7% of the total biomass of shrimp. The IRI value of M. dalei is 13,725 in May. The ranges of Shannon–Wiener diversity index (H′), Pielou's evenness index (J) and the Margalef's species richness index (D) of the shrimp community were 1.40–1.61, 1.20–1.45 and 0.41–0.51, respectively. The Margalef's species richness index (D) was low in two months. MDS and CLUSTER analyses revealed that all the sampling stations in both months may be divided into two groups/clusters of Group I and Group II, which were bounded by the 20m isobaths. Through ANOSIM analysis between Group I and Group II in each month, significant differences were found between March and May. BIOENV analysis indicated that the environment factors including bottom salinity, bottom temperature and depth had obvious effects on spatial variations of the shrimp community structure in Haizhou Bay and adjacent waters, and bottom salinity was the most important environmental factor in structuring the spatial structure of the shrimp assemblage. The spatial distribution of shrimp community in Haizhou Bay in spring and the Yellow Sea Warm Current as well as coastal currents were closely related.