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This work explored the bioactivity of ballast water chlorination and investigated influencing factors of the formation of THMs and HAAs under different conditions. The results will provide useful recommendation for ballast water treatment technology.

The spatial distribution, sources, and potential risk of polycyclic aromatic hydrocarbons (PAHs) were systematically investigated in Shanghai port, one of the most important hubs in international trade. The 16 priority PAHs in surface water and sediment were determined. Total concentrations of 16 PAHs (Σ

Heavy metal concentrations in surface waters and sediments of Shanghai port were measured to analyze the spatial distribution characteristics, sources and pollution degrees. The southern Shanghai port was heavily polluted by Cd, Pb, Cr and Cu in water, and the concentrations of Pb, Hg and Zn in sediments exceeded Effects Range Low. Cu, Pb, Cd and Cr in water were positively correlated in group, and they probably derived from industrial and domestic sewage, fossil fuel burning and vehicular pollution and represented 82.47 % of the contribution. Zn, Hg and As contaminations represented industrial and agricultural effluent sources and accounted for the remaining 17.53 %. Heavy metal pollution of Yangshan Port water was at high pollution, and the remaining sites were at low pollution. Most of the sampling sites were at moderate ecological risk in sediments, and the pollution of Cd, Hg and Zn were serious.

Previous studies have found differences between communities of benthic macroinvertebrates living in constructed tidal flats compared with natural ones. We analyzed the distributional characteristics of benthic macroinvertebrates in a blowing sand reclamation area (Area A), a dike-building silting area (Area B), an out-of-siltation area (Area C), and a natural tidal flat (Area D) in order to characterize the community structure and diversity of benthic macroinvertebrates in a human-disturbed estuarine tidal-flat wetland. A total of 32 benthic macroinvertebrate species were identified (Area A = 7; Area B = 12; Area C = 10; Area D = 27). The diversity index was variable where: Area B 0.05) in the abundance and biomass of Areas A, C, and D. An abundance/biomass curve showed that the habitat in Areas A, B, and C could be categorized as moderately disturbed, whereas Area D was categorized as undisturbed. The results of cluster analysis suggested distinct assemblages in the four sampling areas. Reclamation raised the altitude of tidal flats, weakening the tidal power and changing the physical and chemical parameters of the water, leading to a change in the community structure of benthic macroinvertebrates. Keywords: Reclamation area, Tidal flat, Benthic macroinvertebrates, Community structure

Phytoplankton diversity and abundance were determined in ballast water from 26 vessels in the Shanghai Yangshan Deep-Water Port from April 2015 to January 2016. In total, 84 species of phytoplankton were identified, belonging to 43 genera and 5 phyla. Bacillariophyta (75.0%, including 30 genera and 63 species) were the dominant algae in the ballast water. Their density ranged from (5.55±9.62) SD to (1.878±0.872)×10 3 cells/L, with a mean of 410.1 cells/L. Nine potentially harmful phytoplankton taxa were detected: Ceratium furca, Ce. marcroceros, Leptocylindrus danicus, Coscinodiscus radiatus, Co. granii, Prorocentrum micans, Melosira sulcata, Meuniera membranacea and Skeletonema costatum. Our survey and identification results showed that Microcystis aeruginosa, Ankistrodesmus falcatus and Scenedesmus survived in the high-salinity ballast water, even though they are freshwater species. We identified the common features of surviving phytoplankton and impacts on the phytoplankton assemblage of ballast water age and source. Our goal was to understand the adaptative mechanisms of phytoplankton in ballast water, providing statistical and theoretical support for future ballast water research and suggesting a scientific basis of ballast water management and inspection of vessels entering the port.

Ballast water is a major vector of invasion by protozoans and metazoans. Bacterial invasion is less-well understood. We surveyed the bacterial diversity of ballast water from 26 container ships arriving at the Yangshan Deepwater Port, Shanghai, China during 2015-2016. We characterized the ballast microbiome using high-throughput sequencing (HTS) based on V4-V5 region of 16S rRNA genes. We simultaneously monitored physicochemical parameters of the ballast water, including temperature, pH, dissolved oxygen (DO), salinity, turbidity, total suspended solid (TSS), particulate organic carbon (POC), NO2, NH4, PO4. Proteobacteria was the dominant phylum, comprising more than 50% of the OTUs of almost all vessels, followed by Bacteroidetes (12.08%), Actinobacteria (4.86%) Planctomycetes (3.24%) and Cyanobacteria (1.95%). The relative abundance of Cyanobacteria differed among vessels. It was negatively correlated with temperature, NO3, pH, TSS, PO4, and turbidity and positively correlated with NH4, POC. The genus Synechococcus was the most common Cyanobacteria in our results. Escherichia coli were relatively rare; they are indicator-species of D-2 standards published by the IMO. The relative abundance of the genus Vibrio ranged from 0.003% to 24.88% among different vessels. Our results showed that HTS was able to profile the bacterial communities in ballast-waters, even when the approach was restricted by technical and other obstacles.

Biological invasions and loss of biodiversity are serious problems of increasing globalization. The hypothesis that resting eggs in ballast sediments from transoceanic ships provide an invasion of nonindigenous species was tested by directly comparing egg communities between ballast and natural sediment. The richness, abundance and taxonomic composition of resting eggs were quantified for sediments collected from transoceanic ships arriving at Shanghai Port and natural seafloor of the Yangtze River Estuary . Twelve species were identified in ballast sediments with an average abundance of 19.0 ind. kg −1, while eleven species were identified in natural sediments with an average abundance of 55.3 ind. kg−1. Seven of twelve ballast species were potential invaders compared with natural sediments. The invertebrate communities of resting eggs in ballast sediments differed from those in natural sediments, based on non-metric multidimensional scaling and analysis of similarity. Hatching experiments on resting eggs from ballast sediments showed that there were 1.4 ind. kg−1 copepod nauplii hatched within the first 24 h, suggesting the invasive risk would be present during the first day of de-ballasting. These results indicate that sediments within ballast tanks posed a potential risk for estuarine communities.

The introduction of species through the release of ballast water has become a major threats to marine biodiversity and ecosystem function worldwide. China is one of the top trading countries, yet little is known about exotic species in the ballast water of ships coming to its ports. Here, we review the biological surveys of ballast water from major Chinese ports. These surveys reveal that 40 species of non-indigenous phytoplankton that, belong to 25 genera and five phyla, have been observed in ballast water. The dominant species are diatoms and dinoflagellates. There were 17 red-tide causing species observed, five of which are noxious algae. Seventeen species of non-indigenous zooplankton have been reported, most of them (11) copepods. There were also 22 species of pathogenic bacteria recorded, including Vibrio alginolyticus, V. carchariae, V. parahaemolyticus, and V. vulnificus. These studies show that species introduction through ballast water potentially a serious threat to the ecology and human health in China. More research, including collaboration with the international community, is urgently needed to address this problem.

The presence of disinfection by-products (DBPs) releasing from ballast water management systems (BWMS) can cause a possible adverse effects on humans. The objectives of this study were to compute the Derived No Effect Levels (DNELs) for different exposure scenarios and to compare these levels with the exposure levels from the measured DBPs in treated ballast water. The risk assessment showed that when using animal toxicity data, all the DNELs values were approximately 10(3)-10(12) times higher than the exposure levels of occupational and general public exposure scenarios, indicating the level of risk was low (risk characterization ratios (RCRs)

Ballast water is a common vector for the transport of invasive species to new marine and aquatic environments. We used a metagenomics approach to examine the diversity and composition of potential pathogens communities in ballast water from ships in the route of China- Southeast Asia (CSEA). 16 kinds of potential pathogenic genus were detected in the ballast water. Interestingly, the ballast holding time had an important effect on the distribution of potential pathogens in ballast water. The abundance of Pseudoalteromonas in the longer ballast water holding time was less than the shorter ballast water holding time. Bacteroides had completely disappeared in the long ballast holding time samples. Moreover, The Shannon index of samples with longer ballast water holding time (1.80 ± 0.07) was higher than those with shorter ballast water holding time (0.83 ± 0.13). The potential pathogenic genus (Arcobacter, Aeromonas, Enterobacter and so on) lived in the long ballast holding time vessels had more diversity. Besides, the total suspended solids (TSS), total organic carbon (TOC) and particulate organic carbon (POC) had a strong positive correlation with most potential pathogens in the ballast water, while the dissolved oxygen (DO) had a clear negative correlation with the potential pathogens in the longer ballast holding time samples. In conclusion, these results provide detailed descriptions of the characteristics of the potential pathogens present in ballast water, document significant potential pathogens diversity, and indicate the importance of ballast holding time for potential pathogens lived in ballast water.

Invasive species generally possess unique characteristics that allow them to survive the invasion process in order to establish and spread in new habitats. Successful invaders must resist both physical and physiological stresses associated with the changing environment. A common littoral barnacle, Chthamalus challengeri Hoek, 1883 (Crustacea, Cirripedia), which is native to Japan, South Korea and northern China, has become established in the high-littoral zone adjacent to Yangshan Port, Shanghai, China. A comparison of the morphology of Chthamlus species from Zhoushan archipelago with previous description indicates the occurrence of C. challengeri. The new immigrant becomes a dominant species in certain high-intertidal habitats of the adjacent area to of Yangshan Port. C. challengeri was found in part of sampling sites in Zhoushan in 2010; however, it dispersed to all the eleven sampling sites in 2012. Densities of C.challengeri had increased over 10 times in the last 2 years, with the highest mean value reaching 39533 ± 6243 ind. m−2 in the new habitat. The specific ratios of both operculum area (Sa) to base area (SA) and average height of parietal plates (H) to length of base (L) revealed that C. challengeri displays morphological changes to resist stronger currents in the new habitats for invasion.

Silica/polydopamine/silver (SiO2/PD/Ag) nanoparticles (NPs) with a core–shell–satellite structure were fabricated and the mechanisms of their antibacterial activity were investigated. In this reported work, the results of the reactive oxygen species (ROS) assays, the deoxyribonucleic acid (DNA) damage assays and a cell morphology observation confirmed that Vibrio natriegens, a gram negative bacterium and Bacillus subtilis, a gram positive bacterium could be inhibited by the NPs. Gram negative bacteria exhibited more sensitivity towards the Ag NPs because these NPs were associated with penetration into the cytoplasm, with the subsequent local interaction of Ag with the cell components; thus, causing damages to the cells. SiO2/PD/Ag NPs produced ROS which caused damage to the DNA leading to the suppression of transcription as detected by a reporter gene assay. Furthermore, ROS induced membrane damage was determined by transmission electron microscopy. Thus, the mechanisms of antibacterial activity were interpreted more precisely by using the aforementioned experiments. The results revealed that the production of ROS and damage to the membrane were the two major mechanisms of the bactericidal action of SiO2/PD/Ag NPs; thus, these NPs could be employed as effective antifouling agents.

This study expands on recent reports that direct development in the Chinese potamid freshwater crab Sinopotamon yangtsekiense involves the completion of all brachyuran larval stages (nauplius, zoea, and megalopa) inside the egg case during embryonic development. Detailed studies of embryonic development in this species revealed the presence of an additional larval stage (the egg-juvenile) between the megalopa and the free-living hatchling crab. We described and compared the appendages of the head, thorax, and abdomen of the egg-juvenile with those of the hatchling crab in S. yangtsekiense. Significant differences were found between most of the appendages of these two stages with a soft exoskeleton in the egg-juvenile, no joint articulation, a slimmer appearance, and a lack of setae when compared with the newly emerged free-living hatchling crab. These modifications of the appendages are related to the confinement within the egg case of the egg-megalopa and egg-juvenile during direct development, and the need for the free-living hatchling freshwater crab to move, feed, and respire. In marine crabs, the megalopa gives rise to the first crab stage whereas in freshwater crabs the egg-juvenile follows the megalopa and immediately precedes the free-living first crab stage.

Rotifer community structure was investigated in Yangcheng Lake in 2008. Dominant species and species diversity indices were determined and QB/T was used to assess water quality. The annual average density and biomass of the rotifers in Yangcheng Lake was 2 894 ± 1 006 ind./L and 12.47 ± 10.28 mg/L, respectively. The highest densities were observed in the western portion of the lake in March, but the highest biomass occurred in inflowing creeks in September. Within a year of monitoring in Yangcheng Lake, 93 species were identified and the dominant species were found to be Polyarthra trigla, Brachionus angularis, Keratella cochlearis, Keratella valga, Brachionus calyciflorus, and Filinia major. Of the species recorded, 75 were pollution indicator species. Density and biomass exhibited significant positive correlations with water temperature (R = 0.209, P = 0.003; R = 0.446, P = 0.000), but the peak density showed two lags in response to chl a. According to the Jaccard similarity index (SJ), the greatest similarity among dominant species occurred between creeks and the eastern part of the lake. The annual average Shannon-Wiener diversity index H′, Margalef richness index D and Pielou evenness index J were 1.96 ± 0.34, 1.61 ± 0.50 and 0.77 ± 0.10, respectively. In all four areas of Yangcheng Lake, β-mesosaprobic species comprised the largest share of pollution indicator species. These data suggest that Yangcheng Lake is mesosaprobic.

This paper focuses on the developmental changes that take place inside the eggs of the semi-terrestrial freshwater crab, Sinopotamon yangtsekiense, from Qiantang River in Zhejiang Province, China. The egg consists of two layers, a thick outer membrane and a thin inner membrane that encloses the fluidfilled embryonic sac. Development in this species took up to 77 days, after which the free-living juvenile hatchling crab emerged from the egg. During development the embryo underwent a series of morphological changes that corresponded to the free-living larval stages of marine crabs, and the yolk mass decreased in size and changed color (from creamy pale yellow, to orange, and finally grey). The eggs remained attached to the pleopods in the female’s abdominal brood pouch during development and showed a great deal of independence from water. Embryos developed normally whether they were immersed in water or in air. The implications of this adaptation for freshwater crab evolution are discussed.

The true freshwater crabs (Crustacea, Decapoda, Brachyura) are highly adapted to life in freshwater and complete their life cycle entirely independently of sea water. All true freshwater crabs exhibit direct development and lack the free-living larval forms (zoea and megalopa) typical of most other brachyurans. After a prolonged embryonic period (during which they pass through the typical brachyuran larval forms embryologically) the eggs of true freshwater crabs hatch to produce juvenile (hatchling) crabs. We provide here the first report and description of the continuous record of embryonic development from egg-laying up to hatching in the Chinese true freshwater crab Sinopotamon yangtsekiense Bott, 1967 (Potamoidea, Potamidae). Direct development (complete secondary embryonization) in S. yangtsekiense was observed to take 77 days and to include an additional embryonic phase (termed here the egg-juvenile-crab) that occurs in the embryo between the imprisoned megalopa and the newly-emerged juvenile (hatchling) crab. This is significant because the only other freshwater crab whose embryonic development has been studied in detail is Potamon fluviatilis (Potamidae) which takes 45–47 days and involves only nine embryonic stages.

The tadpole shrimp, Triops sinensis, was discovered in the paddy fields of the Shouchang River watershed. The gut contents of the shrimp from these field populations were analyzed in order to quantify their dietary patterns. Some species of tadpole shrimps were found to prey on mosquito larvae as well as uproot weeds. Mosquito larvae and weeds were seldom found in the paddy fields which the tadpole shrimp inhabited in the Shouchang River watershed. The results further showed that the larvae of these tadpole shrimp mainly feed on algae and rice lamina. The tadpole shrimp could feed on animal food including protozoa, nematodes, rotifers, crustaceans, and aquatic insect larvae, though the animal food was subsidiary.

The ecosystem of the Three Gorges in the Yangtze River was changed into an artificial lake (reservoir) ecosystem after impoundment in June 2003. We surveyed the seasonal variation and spatial distribution of copepods from April 2004 to January 2005 in order to provide data for clarifying the successional pattern of the ecosystem. From Jiangjin to Maoping, eight copepod species were collected and classified into Calanoida (2), Harpacticoida (1), and Cyclopoida (5). Among them, Mesocyclops pehpeiensis, M. leuckarti and Sinocalanus dorrii had a relatively wide distribution. No distinct difference in species number was found among the sampling sites, but the species composition was different. Species composition, distribution and density of copepods showed significant seasonal variations. In addition, copepod density showed an obvious gradient with the distance from the reservoir dam: the nearer to the dam, the denser the copepods.

The foregut, mid-gut and hind gut of Eriocheir sinensis from the first Zoea to Megalopa were dissected under asepsis condition. Bacteria were separated by plate culture after liquid medium culture. A chitin digestive bacterium was separated from the first Zoea foregut. The chitin digestive bacteria weren't founded in the same experiment from the second Zoea to Megalopa. The chitin digestive bacteria showed roundness, protuberance, glassy humid, margin regular, milk-yellow, aerotolerant anaerobe, and growing intently surrounding the chitin on the plate culture medium. The chitin could promote the growth rate of some digestive bacteria in larval gut of the crab.