The distribution of zooplankton and the influencing environmental factors in the South Yellow Sea in the summer

Abstract

Zooplankton were sampled using large plankton net (LPN) (mesh size: 505 μm) and medium plankton net (MPN) (160 μm) in the summer of 2008. 96 and 87 zooplankton species were identified in LPN and MPN, respectively; Calanus sinicus, Aidanosagitta crassa, and Oithona plumifera were common dominant species between the two nets; other dominant species in MPN, such as O. similis, were rare in LPN. The average abundance was 228.99 ± 130.06 ind./m3 and 2835.05 ± 3356.37 ind./m3 in LPN and MPN, respectively. The average biomass was 194.56 ± 130.06 mg/m3 and 216.45 ± 131.89 mg/m3. The diversity indices were also higher in MPN. Correlation analysis indicated that the abundance was negatively correlated with sea bottom temperature, which meant that zooplankton species tended to be clustered in the Yellow Sea Cold Water Mass. The diversity indices were negatively correlated with salinity, which indicated that diversity was higher in sea areas that were affected by Changjiang River Diluted Water.