The Research Of Phytoplankton Composition And Characteristic In Ballast Water Of Three Typical Routes At Yangshan Port

A total of 33 ballast water samples on three typical Lines(Sino-America Line,Sino-Europe Line and Sino-Australia Line)for four seasons from April 2015 to April 2016 were collected and analyzed.The species of plankton in the ballast water as well as their variation with the season were identified;the rules in the species composition of the plankton and their community characteristics in the ballast water of different Lines were presented.The biological adaptation mechanism in the ballast water was preliminarily explored.The study enriched theoretical support for ecological research on ballast water and provides reference for the detection of ballast water on ships arriving at Yangshan Port,the prevention and control of foreign organisms and the national ballast water test and control after the Ballast Water Convention takes effect.The research results show that: 1.14 ballast water samples on Sino-America Line were used,which were from the Chinese ports and adjacent waters,South Korea,Central Pacific Highlands and the American ports,respectively.The ballast water age varied within 3-158 days.Except for CA(158 days)and EU(103 days),the ballast water ages of other samples were all lower than 70 days.A total of 4 phyla,26 genera and 51 species of phytoplankton were identified.The density of phytoplankton varied from(2.22±2.54)×102-(1.878±0.87)×104ind./L.Among them,Bacillariophyta was a dominant phylum,including 18 genera and 37 species.Water age was not significantly correlated with the density and species number of the phytoplankton in the ballast water(P>0.05),and the density of the phytoplankton in autumn and winter was decreased.The density of zooplankton varied from 0-(3.36±0.26)ind./L with an average density of 4.4 ind./L.The zooplankton in summer had more species,and the ballast water age was significantly and negatively correlated with the abundance of zooplankton.2.The 15 ballast water samples on Sino-America Line were mainly from Chinese ports and adjacent waters,Japan,Singapore,Malaysia,Arabian Sea,the High Seas of Indian Ocean and European ports.CF was a sample with the longest ballast time reaching 439 days;ME had a water age of 110 days;the water ages of other samples were all below 60 days.A total of 4 phyla,29 genera and 56 species of phytoplankton were identified.Among them,Bacillariophyta was a dominant phylum,including 19 genera and 43 species and accounting for 67.8% of all species.Coscinodiscus occupied a dominant position as a genus.Pyrrophyta accounted for 12.5% of all species,including 4 genera and 7 species;there were also Chlorophyta(3 species)and Cyanophyta(3 species).The number of species for phytoplankton was 2-21(as shown in Fig.3-2)and its density varied from(77.8±53.0)-(1.15±0.63)×103ind./L.The density of zooplankton varied from(0-26±3.92)ind./L with an average density of 2.81 ind./L.The number of species for zooplankton was 0-11.Copepoda Nauplius was an absolutely dominantly species.The season and ballast water age were not significantly correlated with the densities and species numbers of phytoplankton and zooplankton.3.4 ballast water samples on the Sino-Australia Line were mainly from Japan and Pacific High Seas.The ballast water age varied from 35-156 days.GM,the sample with the longest water age,had a water age of 156 days,which was taken from Osaka Port in Japan.A total of 2 phyla,7 genera and 8 species of phytoplankton were identified.A total of 8 species of zooplankton were detected,and Copepoda Nauplius was an absolutely dominant species.The number of species and abundance of phytoplankton were not significant correlated with water age and ballast season.CX in summer had significantly higher density and number of species for zooplankton compared with other samples.4.The density of phytoplankton was significantly and positively correlated with the contents of nitrite nitrogen and phosphate,while the density of zooplankton increased with the rise of contents of nitrite nitrogen and phosphate.In this study,based on the analytical results of 33 ballast water samples,it could be known that the abundance and species number for phytoplankton and zooplankton in the ballast water were all not significantly correlated with water age.The temperature of ballast water was affected by season;the number of species for phytoplankton was significantly and negatively correlated with the temperature,which means that the former decreased with the increase of the latter.In addition,the density of phytoplankton decreased with the rise of salinity;compared with nearshore samples,the offshore samples had higher salinity;after the offshore ballast water was changed,the abundance of plankton would decrease significantly.Despite of the differences in Line and water age,in terms of phytoplankton,Bacillariophyta and Pyrrophyta are dominant phyla;phytoplankton mainly consists of eurythermal and euryhaline worldwide cosmopolitan species,cosmopolitan species of north temperate zone and fresh water species.More obviously,the samples on the Sino-America Line were more abundant phytoplankton than the samples on the Sino-Europe and Sino-Australia Lines.A small amount of Chrysophyta was only found in the samples on the Sino-America Line.there was no significant difference in the distribution of phytoplankton species for different Lines.The main groups were widespread cosmopolitan species of temperate zone,which mainly consisted of copepods and their nauplius groups.A small amount of cladocerans was found only in the samples on the Sino-Europe Line,and no other mollusca,polychaetes and other biological groups were discovered.