Abstract:
Based on the bottom trawl surveys in Qinzhou Bay in 2015 and 2016, the structure of nekton communities in Qinzhou Bay was preliminarily analyzed. The results showed that there were totally 55 nekton species found by the surveys. The dominant species is defined when index of relative importance (
IRI) is equal or larger than 200. Thus, they were
Charybdis hellerii,
Metapenaeus affinis,
Metapenaeus joyneri,
Parapenaeopsis hungerfordi and
Oratosquilla oratoria in the surveys. The dominant species caught tended to be smaller and younger and the fish catches and standing crops tended to decline gradually in general compared with the historical data. ShannonWiener index (
H′), Margalef index (
D) and Pielou index (
J′) change little in 2015 and 2016 though they differed from station to station. Moreover, the biomass and density of nekton were higher in 2016 than in 2015. However, the nekton diversities were lower than those in Beibu Gulf and in the shallow sea areas on the shelf of northern South China Sea.