Abstract:

To understand the status of nekton communities and diversity in the coastal waters of south-central Zhejiang Province, we carried out two bottom trawl surveys in April and May of 2016. By using diversity index and redundancy analysis, we studied the composition of functional groups. We divided 166 species of nekton into six functional groups according to their feeding habits. The average abundance percentage of zooplanktivores/piscivores functional group was the highest while that of benthivores functional group was the lowest. Meanwhile, the average biomass percentage of zooplanktivores functional group was the highest while that of detritivorous functional group was the lowest. The results of ANOSIM showed a significant monthly difference between functional group structure of nekton communities in April and May, and the mean value of functional group diversity was 1.30 and 1.23 in those months, respectively. Functional group diversity of nekton communities was significantly positively correlated with the total biomass of large individual species (body mass > 50 g), and functional group diversity was positively correlated with species diversity. Redundancy analysis showed that the piscivores functional group were greatly affected by temperature, while benthivores functional group was greatly affected by water depth. Through the analysis of functional group composition, we found the nekton community structure was stable in the coastal waters of south-central Zhejiang Province.

Key words: south-central Zhejiang Province, nekton, functional group, diversity, environmental factors