This study investigated the microbial structure in the surface seawater from five coastal sites around Xiamen Island, China, over four seasons to evaluate seasonal environmental fluctuations impact on them. This subtropical island is characterized by long, hot, humid summers, and short, mild, dry winters. All sites were dominated by Proteobacteria, Bacteroidetes, Cyanobacteria, and Firmicutes; microbial community composition was similar across four seasons. However, larger proportions of Gammaproteobacteria and Bacillus were observed during the summer than during any other season. The high ratio of Bacillus, Bacteroidetes, and Clostridia richness to Alphaproteobacteria richness in the summer, suggested that the sites we tested were heavily affected by waste water to other seasons. Correlation-based network analyses among the bacterial species and environmental variables indicated important connections between physiochemical variables and specific taxonomic groups. Collectively, our results suggested that seasonal shifts and wastewater pollution together shape the structures of the microbial communities around Xiamen Island.

In this study, we examined radioactivity simultaneously in surface marine sediments and coral skeletons collected from 12 locations of the fringing and atoll reefs in the South China Sea. Radioactive level declined from the fringing reefs to atoll reefs because of input of terrigenous minerals in the fringing reefs. Radioactivity was higher in coral skeletons than in marine sediments because of the high ²²⁸Ra activity in coral skeletons. Additionally, an abnormally low ²²⁶Ra/²³⁸U activity ratio (<0.1) of marine sediments in coral reefs was attributed to the biological process of active uptake of ²²⁶Ra and ²³⁸U from seawater by coral polyps rather than the ingrowth process in the ²³⁸U-²³⁰Th-²²⁶Ra decay chain. Several radiological indices were evaluated in coral reefs and significantly lower than recommended values. Particularly, the average Raₑq in the atoll reefs was <5% of the world's average of Raₑq. Our results displayed typically radioactive status in coral reefs without close-in fallout of anthropogenic radionuclides.

The coastal ecological environments are heavily affected by anthropogenic activities as well as global climate change. Macrofauna can be used as good indicators for benthic ecological quality status due to its relatively slow movement ability under disturbance and a variety of assessment approaches have been established based on the characteristics of macrofauna. The benthic ecological quality of the Bohai Sea, China, is increasingly threatened by anthropogenic activities. In order to accurately assess the benthic ecological quality status in this region, Shannon-Wiener diversity index, ABC curve, AMBI, M-AMBI and macrofaunal feeding evenness index were used. Results showed that the northern Laizhou Bay and Bohai Bay were under slight disturbance while Liaodong Bay, the central Bohai Sea and Bohai Strait were under moderate disturbance. Overall, the ecological quality indicated by the assessment results of AMBI, Shannon-Wiener diversity index and feeding evenness index were better than that by M-AMBI and the ABC curve.

Volcanic CO₂ seeps were successfully used to predict coral reef response to ocean acidification, although toxic elements, often characteristic of hydrothermal vents were rarely reported. We measured the physicochemical conditions, seawater carbonate chemistry and trace elements in Tutum Bay, Papua New Guinea. There, intense emission of hydrothermal fluids and CO₂ expose the coral reef to a seawater pHT between 7.6 and 7.7.Arsenic and silica were enriched by up to six times in surface seawater, while bottom concentrations were lower and thus similar to coral reefs worldwide. Manganese, cesium, iron and zinc concentrations fell into the range of other coastal environments. Our measurements suggest that Tutum Bay is a suitable site to study the response of coral reefs to high pCO₂. Considering that arsenic is a common metal in hydrothermal fluids, its characterization should be included in any study that uses volcanic CO₂ seeps as natural laboratories for ocean acidification.

The golden tide, caused by the brown algae Sargassum horneri, exerts severe influences on the Pyropia aquaculture of Jiangsu coast, China. To study the outbreak of the golden tide in response to increasing greenhouse gas emissions, S. horneri was cultured under four conditions: ambient condition (10 °C, 400 μatm), elevated temperature condition (14 °C, 400 μatm), elevated CO₂ level (10 °C, 1000 μatm), and potential greenhouse condition (14 °C, 1000 μatm). The growth, photosynthetic performances, and inorganic carbon affinity of S. horneri were studied. The results showed that elevated temperature exerted a more pronounced positive influence on S. horneri growth, photosynthesis, and carbon assimilation than CO₂ enrichment. The growth of S. horneri was significantly improved by moderately elevated temperatures, especially under concurrently elevated CO₂ levels. This suggests that the greenhouse effect will benefit growth and carbon sequestration of S. horneri, which may enhance the frequency and scale of golden tides.

Metals are subject to internal subcellular compartmentalization, altering their bioavailability. Thus, subcellular metal assessments are crucial in biomonitoring efforts. Metal distribution in three subcellular fractions (insoluble - ISF, thermolabile - TLF and thermostable - TSF) were determined by ICP-MS in Steno bredanensis specimens from Southeastern Brazil. Associations between metals, metallothionein (MT) and reduced glutathione (GSH) were also investigated. Differential metal-detoxification mechanisms were observed. MT detoxification was mostly noted for As, Cd, and Pb, while Cu, Cr, Hg, Ni, Se and Ti displayed lower MT-associations. Fe, Zn and Se, on the other hand, were poorly associated to MT, and mostly present in the ISF, indicating low bioavailability. This is the first report on subcellular Sn and Ti distribution in cetaceans and the first in this species in Brazil. Potential protective roles of essential metals against toxic elements are postulated. This study indicates that important biochemical detoxification information is obtained through subcellular fraction analyses in marine mammals.

Gelatinous zooplankton including jellyfishes, pyrosomes, and salps serve as important prey items for a number of marine species; however, relatively few studies have examined contaminant concentrations in these animals. Scyphozoans (Aurelia sp., Chrysaora colorata, C. fuscescens, and Phacellophora camtschatica) and Thaliaceans (Pyrosoma sp.) were collected from 2009 to 2011 from Monterey Bay National Marine Sanctuary and analyzed for total mercury and selenium concentrations. In general, mercury (0.0001–0.0016 μg/g wet weight) and selenium (0.009–0.304 μg/g wet weight) concentrations of the sampled organisms were low; however, the two Pyrosoma sp. had total mercury and selenium concentrations that were one order of magnitude higher than the Scyphozoans. There was a significant positive relationship between mercury and selenium concentrations in jellyfishes and pyrosomes, suggesting a potential detoxification mechanism in these lower trophic level organisms. This study provides evidence that trophic transfer of mercury and selenium likely occurs through ingestion of gelatinous prey.

Drill cuttings (DC) are produced during hydrocarbon drilling operations and are composed of subsurface rock coated with hydrocarbons and drilling fluids. Historic disposal of DC at sea has resulted in the formation of large piles on the seabed that may be left in situ following infrastructure decommissioning. This study provides a first insight into the microbial abundance, diversity and community structure of two DC piles from North Sea oil and gas installations. The abundance of both bacteria and archaea was lower in DC than in surrounding natural sediments. Microbial diversity and richness within DC were low but increased with distance from the piles. Microbial community structure was significantly different in DC piles compared to nearby natural sediments. DC bacterial communities were dominated by Halomonas, Dietzia and Dethiobacter. The presence of such organisms suggests a potential function of hydrocarbon degradation ability and may play an active role in DC pile remediation.

Plastic has become abundant in the oceans and proved to be a threat to marine and coastal fauna. In this study, we present the first record of synthetic debris ingested by the shorebird American Oystercatcher (Haematopus palliatus) in Brazil. We collected 24 stomach contents from October 2007 to October 2015 and 58% were juveniles. Synthetic materials were found in 100% of stomachs. Used plastic fragments and plastic pellets were the most frequent items, beige and white were more common colors. Synthetic material may be unintentionally ingested directly through substrate consumption or indirectly through prey consumption. Hence, debris ingestion may be common, representing an impact to coastal birds. Based on our results, we hope to highlight the need for public policies to reduce the disposal of synthetic debris in the oceans and beaches.

The concentrations of nine heavy metals accumulated in different organs of two crab species collected from the South East coast of India were estimated. The order of trace metal concentration in different organs of Portunus pelagicus was Cu > Mn > Cd > Ni > Pb > Co > Hg = Cr = U in gills, Cu > Mn > Cd > Ni > Pb = Co > Hg > Cr = U in hepatopancreas, and Cu > Cr > Ni > Mn > Cd > Pb > Co > Hg > U in muscles, whereas that for Portunus sanguinolentus was Cu > Mn > Cd > Ni > Pb > Co > Hg > Cr = U in gills, Cu > Mn > Cd > Ni > Pb = Co > U > Cr = Hg in hepatopancreas, and Cr > Cu > Ni > Mn > Cd > Co > Pb > Hg = U in muscles. The order of trace metal uptake for different organs was gills > hepatopancreas > muscles. Individual mean bioaccumulation index (IMBI) values varied between 0.0 and 0.52, 0.0 and 0.28, and 0.06 and 0.30 for gills, hepatopancreas, and muscles, respectively. Cr in muscles of P. sanguinolentus and Cu and Cd in all organs of both the species were found to be higher than the maximum permitted concentration recommended by food safety guidelines. Target hazard quotient (THQ) results suggested that there is a potential risk due to Co, Cd, and Cr, particularly for children, if the crab consumption frequency is more than once a month.