RESUMO
Based on the data collected from the bottom trawl surveys in the coastal waters of northern Jiangsu Province from 2009 to 2014, multivariate statistical analysis and other integrated indices were used to analyze the variation in the community structure of fish assemblage over time in the waters. The results showed that 68 species had been caught in the coastal waters of northern Jiangsu Province. There were significant fluctuations in the relative density of fish resources. The mean catch mass per site ranged from 0.75 to 1.62 kg·h-1, and the mean catch individuals per site showed significant decrease in the survey period ranging from 370 to 203 ind·h-1. The mean trophic level (MTL) index varied between 3.58 and 3.72 from 2011 to 2014, being relatively low in 2009-2012 and fluctuating around 3.70 in 2011-2014. The mean body mass of fish community increased from 2.93 to 11.18 g between 2009 and 2014, showing a similar tendency with that of MTL index. Cluster analysis and MDS showed that the six survey years could be divided into two subgroups of 2009-2010 and 2011-2014. The main discriminating species were Syngnathus acus,Ctenotrypauchen microcephalus and Ammodytes personatus for the two subgroups. Further study showed that the pelagic and planktivorous fishes had gradually increased in dominance while cold temperate species and indigenous species had decreased over the years. It was suggested that fish communities in the coastal waters of northern Jiangsu Province underwent a remarkable succession. Advices for the fisheries management in the waters were provided according to the succession pattern, which might contribute to the sustainable utilization of fishery resources.
