Communities In Coastal Waters Research Articles

Гриби класу Dothideomycetes лучних та прибережно-водних угруповань степової зони України

Гриби класу Dothideomycetes лучних та прибережно-водних угруповань степової зони України

Ocean acidification impacts on biomass and fatty acid composition of a post-bloom marine plankton community

A mesocosm approach was used to investigate the effects of ocean acidification (OA) on a natural plankton community in coastal waters off Norway by manipulating CO2 partial pressure (pCO2). Eight enclosures were deployed in the Raunefjord near Bergen. Treatment levels were ambient (~320 µatm) and elevated pCO2 (~2000 µatm), each in 4 replicate enclosures. The experiment lasted for 53 d in May-June 2015. To assess impacts of OA on the plankton community, phytoplankton and protozooplankton biomass and total seston fatty acid content were analyzed. In both treatments, the plankton community was dominated by the dinoflagellate Ceratium longipes. In the elevated pCO2 treatment, however, biomass of this species as well as that of other dinoflagellates was strongly negatively affected. At the end of the experiment, total dinoflagellate biomass was 4-fold higher in the control group than under elevated pCO2 conditions. In a size comparison of C. longipes, cell size in the high pCO2 treatment was significantly larger. The ratio of polyunsaturated fatty acids to saturated fatty acids of seston decreased at high pCO2. In particular, the concentration of docosahexaenoic acid (C 22:6n3c), essential for development and reproduction of metazoans, was less than half at high pCO2 compared to ambient pCO2. Thus, elevated pCO2 led to a deterioration in the quality and quantity of food in a natural plankton community, with potential consequences for the transfer of matter and energy to higher trophic levels

Distribution of structure of macrobenthic communities in coastal waters of Jiangmen, Guangdong

Distribution of structure of macrobenthic communities in coastal waters of Jiangmen, Guangdong

Microbial ecology might serve as new indicator for the influence of green tide on the coastal water quality: Assessment the bioturbation of Ulva prolifera outbreak on bacterial community in coastal waters

Abstract The massive outbreak of Ulva prolifera had brought significant ecological impacts on marine coastal areas. In order to clarify the influence of outbreak of U. prolifera on marine microbial ecosystem, the microbial communities in different stages of blooming were analyzed by high-throughput sequencing. The sequences were clustered into 2979 operational taxonomic units (OTUs), and Shannon estimator varied from 3.241 to 4.892. The OTUs number and Shannon estimator demonstrated that both parameters were higher in samples HY_2–4, QD_2–4, RZ_2–4 than in HY_1, QD_1, RZ_1, indicating that the massive outbreak of U. prolifera caused the increase of microbial community diversity in coastal waters. The outbreak of U. prolifera led to increase in the abundance of some bacteria. According to the network analysis, the differences in hot bacteria in different stages indicated that the outbreak of U. prolifera caused the variation of microbial community. Based on Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway analysis, the abundance of 41 metabolic pathways had changed due to the outbreak of U. prolifera. The microbial community could recover gradually after the disappearance of U. prolifera. The relative abundance of dominant genera Methylophaga, Polaribacter, Marinobacterium, Marivita, Tenacibaculum, Vibrio, Planktomarina, Crocinitomix, Draconibacterium, norank_f_Alteromonadaceae in stage 6 (after the outbreak of U. prolifera) kept the same level as stage 1 (before the outbreak of U. prolifera). These findings suggested that microbial ecology might serve as new indicator for the influence of green tide on the coastal water quality since marine microbial ecosystem could be temporarily bioturbated during the outbreak of the green tide.

Continental-scale spatio-temporal distribution of antibiotic resistance genes in coastal waters along coastline of China

Antibiotic resistance genes (ARGs) have been frequently detected in various matrices all over the world to attract wide attention due to the potential risks. Rare information is available on the pollution of ARGs in the waters of critical ecologically fragile regions such as the coastal zone at a continental scale. Therefore, this study performed field sampling during winter and summer along 18000 km coastline of China to investigate the distribution of target ARGs in coastal waters at a continental scale. The absolute abundances of ARGs in coastal waters showed drastic spatio-temporal variation with a mean value of 8.79 × 104/1.39 × 105 copies/mL in summer/winter, much lower than those in tail water from the maricultural zone or wastewater. The average absolute abundance of class 1 integron-integrase gene (intI1) in coastal waters was 9.68 × 103/4.15 × 104 copies/mL in summer/winter, still lower than that in tail water or wastewater. Quinolone resistance genes were the dominant ARGs in coastal waters to account for over 50% of total ARGs in most of sampling sites. Bacterial communities in coastal waters showed significant difference both at phylum and genus levels. Abundances of ARGs in coastal waters of this study were comparable with those in other regions previously reported. Tail water and wastewater might be the essential sources of ARGs in coastal waters. The findings of this study provided comprehensive information on the pollution status of ARGs in coastal waters at a continental scale, indicating that ARGs pollution has become a crucial stress affecting the sustainable development of coastal regions.

Temporal distribution of zooplankton communities in coastal waters of the northern Bay of Bengal, Bangladesh

The temporal distribution pattern of zooplankton communities was studied in coastal waters of the northern Bay of Bengal, Bangladesh, during a 1-year period of investigation (May 2014-April 2015). Throughout the investigation, a total of 38 zooplankton species were recorded, in details 22 holo-plankton and 16 mero-plankton species. Copepods (Acartia danae, Acartia tonsa, Cyclops biscuspidatus, and Canthocalanus pauper), amphipods (Grandidierella megnae), shrimps (Penaeus indicus and Penaeus merguiensis), Acetes (Acetes indicus), and mysids (Americamysis bahai) were the dominant zooplankton taxa. The maximum abundance of total zooplankton and species richness was recorded in monsoon season whereas abundance of holo-plankton and species diversity was recorded in winter. Multivariate analyses revealed that the temporal pattern of species distribution of zooplankton communities significantly differed among the four seasons. RELATE analysis signified that temporal variation in species distribution and community structure of zooplankton significantly correlated with ecological condition of water. Moreover, BEST matching analysis indicated that NO2-N along with salinity, rainfall, transparency, TDS, TSS and pH were the main driving forces for these temporal variations in species distribution and community composition of zooplankton communities. Finally, correlation analysis showed that species evenness and diversity significantly correlated with salinity, transparency and TDS. These results suggest that zooplankton distribution pattern might be shaped by ecological condition of water in such marine ecosystem and may potentially be used as bioindicators of marine water quality.

Structural and Functional Characteristics of the Phytoplankton Community in Coastal Waters of the Black Sea

The results of a study of the structural and functional characteristics of phytoplankton in the coastal region of the Black Sea using flow cytometry are presented. The data on the seasonal variability of the biomass of three algal groups (Synechococcus, pico-eukaryotic phytoplankton, and nanophytoplankton), chlorophyll a content, percentage of living cells, and FDA (diacetate fluorescein) fluorescence characterizing the functional state of algae are obtained. A significantly positive relationship is found between the values (biomass and autofluorescence of chlorophyll) determined on the flow cytometer and the total content of chlorophyll a, calculated using standard methods. The effect of temperature, illumination, and content of nutrients in water on the biomass and the FDA fluorescence of three isolated groups of algae is shown. The nitrate content and temperature have no significant effect on the abundance of pico and nanophytoplankton, while a reliable relationship is established between the biomass of nanophytoplankton and the concentrations of dissolved forms of mineral phosphorus. An inverse statistically significant correlation is found between the light intensity and the biomass of picoeukaryotic phytoplankton. It is demonstrated that the abiotic environmental factors considered in the study do not significantly affect the FDA fluorescence value, except for temperature: in the warm period of the year, the picophytoplankton are most active in the Black Sea, while the cold period of the year is favorable for the development of nanophytoplankton.

Temperature-Dependent Bifurcated Seasonal Shift of Phytoplankton Community Composition in the Coastal Water off Southwestern Korea

Coastal water around the archipelago off southwestern Korea has been bathed in an unprecedented pool of warm water in summer in recent years. Here, we examined phytoplankton community responses to amplified seasonal temperature fluctuation around the archipelago based on chemotaxonomic analysis in association with physicochemical properties in the shallow coastal water from June 2016 to March 2018. Concentrations of dissolved inorganic nutrients were significantly higher during the warm season than during the cold season. Canonical correspondence analysis revealed that water temperature was a main driver controlling the phytoplankton community. Generalized additive models denoted that small phytoplankton groups (cryptophytes, cyanobacteria, and prasinophytes) were more resistant to high temperatures (> 25°C) compared with diatoms. Indeed, dominance of diatoms was significant (80%) during the cold season and sharply declined (to 49%) during the warm season. Small phytoplankton were dominant (62%) as the water temperature exceeded 22°C. Our results highlight the effects of temperature-dependent bifurcated seasonality on phytoplankton communities in coastal waters. Furthermore, unprecedentedly high summer temperatures in August 2016 coincided with a remarkable increase in the importance (∼70%) of small phytoplankton. Accumulating evidence provides indications regarding future scenarios: while small phytoplankton will probably account for summer blooms, diatom blooms will shift to winter.

Marine microplastic-associated bacterial community succession in response to geography, exposure time, and plastic type in China's coastal seawaters

Microplastics have emerged as new pollutants in oceans. Nevertheless, information of the long-term variations in the composition of plastic-associated microbial communities in coastal waters remains limited. This study applied high-throughput sequencing to investigate the successional stages of microbial communities attached to polypropylene and polyvinyl chloride microplastics exposed for one year in the coastal seawater of China. The composition of plastisphere microbial communities varied remarkably across geographical locations and exposure times. The dominant bacteria in the plastisphere were affiliated with the Alphaproteobacteria class, particularly Rhodobacteraceae, followed by the Gammaproteobacteria class. Scanning electron microscopy analysis revealed that the microplastics showed signs of degradation. Microbial communities showed adaptations to plastisphere including more diverse microbial community and greater “xenobiotics biodegradation and metabolism” in metabolic pathway analysis. The findings elucidate the long-term changes in the community composition of microorganisms that colonize microplastics and expand the understanding of plastisphere microbial communities present in the marine environment.

Role of eddies in structuring the mesozooplankton composition in coastal waters of the western Bay of Bengal

The mesozooplankton community structure of a cold core eddy, moving through a coastal location (Bheemunipatnam) in the western Bay of Bengal (BoB), was studied continuously for 17 days (21st February to 8th March 2016) during Spring Intermonsoon. Vertical profiles of temperature, salinity and Chlorophyll a were measured in 1hr interval. Nutrients and dissolved oxygen were measured in every 3 hrs from 8 discrete depths. Mesozooplankton samples were collected through vertical haul (100 m depth to the surface) in 6 hrs intervals. Cluster analysis delineated the entire sampling days into 3 clusters based on temperature, salinity, anomaly of temperature and salinity in various depth layers Viz., phase I (Pre-eddy: 21st to 24th February), phase II (Core eddy: 28th February to 6th March) and phase III (Transition: 25th to 27th February and 7th to 8th March). The phase I was characterised as a comparatively warm, low saline, less nutrient and oxygenated subsurface water. During phase II, cool, nutrient-rich and oxygen deficient waters in the study location indicating the presence of a cold core eddy. Phase III is an intermediate condition between the phases I and II. Deep chlorophyll maxima (DCM) were shoaled to 23 m in Phase II from a depth of 38 m in Phase I. Mesozooplankton abundance was high during phase II (62320 No. m−2) compared to phase III (41633 No. m−2) and phase I (39510 No. m−2). Altogether 64 copepod species were identified of which, seven were dominant throughout the observation. Twelve species found as the indicator species in the core eddy condition. The high abundance of the Temora turbinata (upwelling indicator), Pleuromamma indica (low oxygen tolerant and highly central BoB reported) and occurrence of oceanic, oxygen minimum zone (OMZ) reported forms as indicator species in phase II is indicative of their entrainment from offshore by eddies. Eddy genesis and their movement tracking appear that this northeastern offshore formed cold core eddy advected to western coastal Bay of Bengal and traversing through the study site during the sampling period. Copepod species composition indicates the eddy trapped biological communities were sustained and retained in the core over a long period, and it advected over a long distance. This study is the first kind of information about northeastern offshore formed cold core eddy carries the plankton community in coastal waters of western BoB on their path and explains copepods community structure can be used as the indicator of eddy water masses.

Revisiting the distribution of oceanic N2 fixation and estimating diazotrophic contribution to marine production

Marine N2 fixation supports a significant portion of oceanic primary production by making N2 bioavailable to planktonic communities, in the process influencing atmosphere-ocean carbon fluxes and our global climate. However, the geographical distribution and controlling factors of marine N2 fixation remain elusive largely due to sparse observations. Here we present unprecedented high-resolution underway N2 fixation estimates across over 6000 kilometers of the western North Atlantic. Unexpectedly, we find increasing N2 fixation rates from the oligotrophic Sargasso Sea to North America coastal waters, driven primarily by cyanobacterial diazotrophs. N2 fixation is best correlated to phosphorus availability and chlorophyll-a concentration. Globally, intense N2 fixation activity in the coastal oceans is validated by a meta-analysis of published observations and we estimate the annual coastal N2 fixation flux to be 16.7 Tg N. This study broadens the biogeography of N2 fixation, highlights the interplay of regulating factors, and reveals thriving diazotrophic communities in coastal waters with potential significance to the global nitrogen and carbon cycles.

Increased CO2 exacerbates the stress of ultraviolet radiation on photosystem II function in the diatom Thalassiosira weissflogii

Diatoms usually dominate phytoplankton community in coastal waters and experience rapid changes of underwater light. However, little is known regarding how increased CO2 would affect diatoms’ capacity in dealing with changing photosynthetically active radiation (PAR) and ultraviolet radiation (UVR). Here, we cultured a globally abundant diatom Thalassiosira weissflogii under two levels of CO2 (400, 1000 ppmv), and then analysed its PSII function during an increase in PAR and UVR to mimic an upward mixing event. UVR noticeably reduced photosystem II (PSII) activity (FV/FM) during the high light exposure, which was more significant for cells grown at the higher CO2 condition. The PsbA removal rate (KPsbA) was synergistically increased by high CO2 and UVR, while the PsbD removal rate (KPsbD) was decreased under higher CO2. Both CO2 and UVR had an inducible effect on sustained phase of nonphotochemical quenching (NPQs). The higher CO2 decreased the ratio of Rubisco large subunit (RbcL) to PsbA regardless of the radiation treatments. It seems that the increased NPQs and turnover of PsbA induced by higher CO2 were not enough to offset the stressful effect it brought about, particularly when higher CO2 was combined with UVR. These findings indicate that increased CO2 may exacerbate the harmful effect of UVR on PSII function in the T. weissflogii through reducing PsbD removal rate and the ratio of RbcL to PsbA during UVR exposure, and thus would affect its abundance and distribution in future ocean environment.

Combined effects of ocean acidification and warming on physiological response of the diatom Thalassiosira pseudonana to light challenges

Diatoms are one of the most important groups of phytoplankton in terms of abundance and ecological functionality in the ocean. They usually dominate the phytoplankton communities in coastal waters and experience frequent and large fluctuations in light. In order to evaluate the combined effects of ocean warming and acidification on the diatom's exploitation of variable light environments, we grew a globally abundant diatom Thalassiosira pseudonana under two levels of temperature (18, 24 °C) and pCO2 (400, 1000 μatm) to examine its physiological performance after light challenge. It showed that the higher temperature increased the photoinactivation rate in T. pseudonana at 400 μatm pCO2, while the higher pCO2 alleviated the negative effect of the higher temperature on PSII photoinactivation. Higher pCO2 stimulated much faster PsbA removal, but it still lagged behind the photoinactivation of PSII under high light. Although the sustained phase of nonphotochemical quenching (NPQs) and activity of superoxide dismutase (SOD) were provoked during the high light exposure in T. pseudonana under the combined pCO2 and temperature conditions, it could not offset the damage caused by these multiple environmental changes, leading to decreased maximum photochemical yield.

A new methodology to assess antimicrobial resistance of bacteria in coastal waters; pilot study in a Mediterranean hydrosystem

The global resistome of coastal waters has been less studied than that of other waters, including marine ones. Here we develop an original method for characterizing the antimicrobial resistance of bacterial communities in coastal waters. The method combines the determination of a new parameter, the community Inhibitory Concentration (c-IC) of antibiotics (ATBs), and the description of the taxonomic richness of the resistant bacteria. We test the method in a Mediterranean hydrosystem, in the Montpellier region, France. Three types of waters are analyzed: near coastal river waters (Lez), lagoon brackish waters (Mauguio), and lake freshwaters (Salagou). Bacterial communities are grown in vitro in various conditions of temperature, salinity, and ATB concentrations. From these experiments, we determine the concentrations of ATB that decrease the bacterial community abundance by 50% (c-IC50) and by 90% (c-IC90). In parallel, we determine the taxonomic repertory of the resistant growing bacteria communities (repertory of Operational Taxonomic Units [OTU]). Temperature and salinity influence the abundance of the cultivable bacteria in presence of ATBs and hence the c-ICs. Very low ATB concentrations can decrease the bacterial abundance significantly. Beside a few ubiquitous genera (Bacillus, Pseudomonas, Shewanella, Vibrio), most resistant OTUs are specific of a type of water. In brackish water, resistant OTUs are more diverse and their community structure less vulnerable to ATBs than those in freshwater. We anticipate that c-IC measurement combined with taxonomic description can be applied to any littoral region to characterize the resistant bacterial communities in the coastal waters. This would help us to evaluate the vulnerability of aquatic ecosystems to antimicrobial pressure.

Release and microbial degradation of dissolved organic matter (DOM) from the macroalgae Ulva prolifera

Release and microbial degradation of dissolved organic matter (DOM) and chromophoric dissolved organic matter (CDOM) from the macroalgae Ulva prolifera were studied in laboratory incubation experiments. The release of DOM and CDOM from Ulva prolifera was a rapid process, and hydrolysis played an important role in the initial leaching of the organic compounds from the algae. Bacterial activity enhanced the release of DOM and CDOM during degradation of the algae and utilization of the released organic compounds. It is calculated that 43±2% of the C and 63±3% of the N from Ulva prolifera's biomass were released during the 20-day incubation, and 65±3% of the released C and 87±4% of the released N were utilized by bacteria. In comparison, only 18±1% of the algae's C and 17±1% of its N were released when bacterial activities were inhibited. The fluorescence characteristics of the CDOM indicate that protein-like DOM was the major organic component released from Ulva prolifera that was highly labile and biodegradable. Bacteria played an important role in regulating the chemical composition and fluorescence characteristics of the DOM. Our study suggests that the release of DOM from Ulva prolifera provides not only major sources of organic C and N, but also important food sources to microbial communities in coastal waters.

Species composition of microzooplankton Tintinnid from the coastal waters of Digha, Bay of Bengal.

Tintinnid species distribution and hydrography were studied in the coastal waters of Digha during winter (November 2015) and summer (March 2016) seasons. Surface water samples were collected from 11 different stations from 0 to 10km offshore with the help of a mechanized trawler. Parameters like tintinnid species enumeration, zooplankton biomass, phytoplankton concentration (total chlorophyll) and abundance, sea surface temperature (SST), pH, transparency, salinity, dissolved oxygen (DO), total phosphate, silicate and nitrate were analysed. A total of 20 different tintinnid species (16 agglomerated +4 non-agglomerated) belonging to 6 genera were recorded from the study area with seasonal variation in tintinnid diversity, i.e. higher in summer (total 2745 individual/l) compared to winter (total 1191 individual/l). Tintinnopsis was the most dominant genus during both the seasons, i.e. 2100 individual/l in summer and 727 individual/l in winter, contributing about 76 and 61% population for the respective seasons. The correlation between species and water quality parameters showed that Tintinnopsis sp. abundance was significantly regulated by nitrate concentration, salinity, dissolved oxygen, water transparency and pH. However, the mentioned hydrological parameters were not the only factors regulating the tintinnid abundance. Tintinnid abundance was also found to be positively related with transparency (r=0.732) and salinity (r=0.524) and moderately related with dissolved oxygen (r=0.488) whereas strong negative relation (at p≤0.05) was established between tintinnid abundance with nitrate (r=-0.681) and pH (r=-0.561). Bray-Curtis cluster analysis of tintinnid species showed more than 60% similarity. Shannon's diversity index (H'), Simpson's evenness index (D) and Margalef's species richness index were found to be higher in summer, i.e. 1.61, 0.729 and 1.612, compared to the winter season, i.e. 1.139, 0.597 and 1.268. k-dominance curve showed maximum abundance of Tintinnopsis baltica in winter and Tintinnopsis gracilis in summer. Principal component analysis (PCA) was analysed to find out the environmental variables affecting different tintinnid species diversity. A significant spatiotemporal variation in Tintinnid population distribution was observed from two-way ANOVA. The results reflect significant seasonal (F=840.0), spatial (F=47.3) and interactive variation (F=71.2) among the ciliate microzooplankton at n=66, p≤0.001. High chlorophyll content and phytoplankton population in summer indicated that tintinnid diversity in the season was positively influenced by producer community in coastal waters of Digha.

Seasonal Succession of Free-Living Bacterial Communities in Coastal Waters of the Western Antarctic Peninsula.

The marine ecosystem along the Western Antarctic Peninsula undergoes a dramatic seasonal transition every spring, from almost total darkness to almost continuous sunlight, resulting in a cascade of environmental changes, including phytoplankton blooms that support a highly productive food web. Despite having important implications for the movement of energy and materials through this ecosystem, little is known about how these changes impact bacterial succession in this region. Using 16S rRNA gene amplicon sequencing, we measured changes in free-living bacterial community composition and richness during a 9-month period that spanned winter to the end of summer. Chlorophyll a concentrations were relatively low until summer when a major phytoplankton bloom occurred, followed 3 weeks later by a high peak in bacterial production. Richness in bacterial communities varied between ~1,200 and 1,800 observed operational taxonomic units (OTUs) before the major phytoplankton bloom (out of ~43,000 sequences per sample). During peak bacterial production, OTU richness decreased to ~700 OTUs. The significant decrease in OTU richness only lasted a few weeks, after which time OTU richness increased again as bacterial production declined toward pre-bloom levels. OTU richness was negatively correlated with bacterial production and chlorophyll a concentrations. Unlike the temporal pattern in OTU richness, community composition changed from winter to spring, prior to onset of the summer phytoplankton bloom. Community composition continued to change during the phytoplankton bloom, with increased relative abundance of several taxa associated with phytoplankton blooms, particularly Polaribacter. Bacterial community composition began to revert toward pre-bloom conditions as bacterial production declined. Overall, our findings clearly demonstrate the temporal relationship between phytoplankton blooms and seasonal succession in bacterial growth and community composition. Our study highlights the importance of high-resolution time series sampling, especially during the relatively under-sampled Antarctic winter and spring, which enabled us to discover seasonal changes in bacterial community composition that preceded the summertime phytoplankton bloom.

Anthropogenic versus mineral aerosols in the stimulation of microbial planktonic communities in coastal waters of the northwestern Mediterranean Sea

The atmosphere of the northwestern (NW) Mediterranean Sea is affected by continuous inputs of anthropogenic aerosols and episodic Saharan dust events. These atmospheric inputs deliver to the surface waters high amounts of macronutrients and trace metals that can constitute their main source at certain times of the year. The effect of both anthropogenic and crustal particles over the autotrophic and heterotrophic planktonic community assembles was evaluated through three microcosm experiments carried out in the summer of 2013 and in the winter and spring of 2014 at an urban coastal location of the NW Mediterranean (Barcelona, Spain). Particles were added to seawater at a concentration of 0.8mgl−1. The results showed that (i) a greater stimulation of the whole community was observed in summer and spring than in winter; (ii) both kinds of aerosols produced an increase in the growth of phytoplankton, although the stimulation of nanoeukaryotes was significantly larger with anthropogenic aerosols; and (iii) bacterial abundance increased more with mineral dust, whereas bacterial production was more stimulated with anthropogenic inputs. Overall, the effect of atmospheric particles was dependent on their composition and solubility in seawater, as well as on the initial biogeochemical conditions present in the seawater and had the potential to change the net metabolic balance of the microbial planktonic community.

Mechanisms of subtropical plankton transport into the coastal waters of southern Primorye, a case of <i>Paracalanus parvus</i>

Results of long-term studies of zooplankton species in the Amur Bay (Japan Sea) are analyzed. Two seasonal «waves» of the allochtonous species are defined: the first in the early summer that is formed mainly by inter-zonal copepods spawning in the deep layers ( Metridia pacifica , Neocalanus plumchrus, Calanus glacialis ) and the second in the late summer that is represented by warm-water copepods of subtropical origin ( Calanus pacificus and Paracalanus parvus ) obviously transported from the southern Japan Sea by currents. The latter species is able to dominate in the zooplankton community of coastal waters in the early-autumn season. Variations of this mass species abundance in the Amur Bay under changes of wind-driven upwelling/downwelling circulation are investigated using an empirical advective model of its cross-shelf transport. There is found that strong summer southern on-shore winds (summer monsoon) are favourable for its high abundance but in these conditions it is transported toward the coast by the deep compensatory flow developed only after the summer monsoon change to the winter monsoon with opposite direction; that’s why the high abundance is observed in autumn, in September-October. In the years with weak summer monsoon the species is transported to the bay in mass by the surface on-shore wind-driven flow earlier, in August, but its number decreases after the monsoon change, so the maximum of abundance is not high. Patterns of the transport by cross-shelf currents depend supposedly on the depth of plankton concentration. Recent strengthening of summer monsoon causes heightening of P. parvus abundance in the coastal waters at southern Primorye, up to extreme high values in 2013, but climatic trend of the summer monsoon intensity is negative, so decreasing of this species transport toward Primorye coast and its abundance in the coastal waters, as the Amur Bay, can be expected in the nearest future.

Metaproteomics reveals the major microbial players and their biogeochemical functions in a productive coastal system in the northern South China Sea.

We study the metaproteome of the GF/F-prefiltered fraction of a microbial community from Shantou coast summer surface waters using a shotgun proteomic approach. Spectra attributed to the marine Roseobacter clade (MRC), the oligotrophic marine Gammaproteobacteria (OMG) group and Flavobacteria dominated in the microbial community, accounting for 21.0%, 23.2% and 12.7% of all of the detected spectra, respectively, whereas the SAR 92 clade accounted for 50% of the OMG group. The abundance of TonB-dependent receptors (TBDRs) was detected and the majority of TBDRs were attributed to the OMG, whereas a large number of ABC transporters matched to the MRC, which suggests niche separation in the microbial community. Expression of proteorhodopsin and RagB/SusD from Flavobacteria facilitates their attachment and growth on algal-derived organic matter. Taurine and glycine betaine appear to be an important source of carbon and nitrogen for the Rhodobacteraceae and SAR11 cluster. The detection of carbon monoxide dehydrogenase, formate dehydrogenase, O-acetylhomoserine sulfhydrylase and sulfur oxidation protein from the MRC demonstrated that members of the MRC play important roles in coastal ocean biogeochemical cycles. This study provides the first insight into functional processes occurring in microbial communities in coastal waters in the South China Sea.