A twelve year (2000−2011) study of three coastal lagoons in the Gulf of Mexico was conducted to assess the impacts of local watershed development and tropical storms on water quality. The lagoons have similar physical and hydrological characteristics, but differ substantially in the degree of watershed urban development and nutrient loading rates. In total the lagoons experienced 22 storm events during the period studied. Specifically, we examine (1) whether there are influences on water quality in the lagoons from watershed development, (2) whether there are influences on water quality in the lagoons from storm activity, and (3) whether water quality is affected to a greater degree by watershed development versus storm activity. The two urbanized lagoons typically showed higher water-column nitrate, dissolved organic nitrogen, and phosphate compared with the non-urbanized lagoon. One of the urbanized lagoons had higher water-column chlorophyll a concentrations than the other two lagoons on most sampling dates, and higher light extinction coefficients on some sampling dates. The non-urbanized lagoon had higher water-column dissolved oxygen concentrations than other lagoons on many sampling dates. Our results suggest long-term influences of watershed development on coastal water quality. We also found some evidence of significant storm effects on water quality, such as increased nitrate, phosphate, and dissolved oxygen, and decreased salinity and water temperature. However, the influences of watershed development on water quality were greater. These results suggest that changes in water quality induced by human watershed development pervade despite the storm effects. These findings may be useful for environmental management since they suggest that storms do not profoundly alter long-term changes in water quality that resulted from human development of watersheds.

Per- and polyfluoroalkyl substances (PFASs) have been detected around the globe in drinking water, in various media at release sites, in human blood serum, and in non-human biota tissue. These compounds are emerging contaminants due to the rapidly evolving regulatory landscape, which is driven by advances in toxicological and risk assessment knowledge emanating from academia and government research organizations. A robust understanding of these developments is required to appreciate the basis, present state, and future direction of regulation and management of PFASs. This paper summarizes recent toxicological and ecological risk assessment information, ongoing research, and current guidelines governing PFASs for the protection of non-human biota.

Here we present the large-scale distribution of microplastic contamination in beach sediment across Europe. Sediment samples were collected from 23 locations across 13 countries by citizen scientists, and analysed using a standard operating procedure. We found significant variability in the concentrations of microplastics, ranging from 72±24 to 1512±187 microplastics per kg of dry sediment, with high variability within sampling locations. Three hotspots of microplastic accumulation (>700 microplastics per kg of dry sediment) were found. There was limited variability in the physico-chemical characteristics of the plastics across sampling locations. The majority of the microplastics were fibrous, <1mm in size, and blue/black in colour. In addition, using Raman spectrometry we identified particles as polyester, polyethylene, and polypropylene. Our research is the first large spatial-scale analysis of microplastics on European beaches giving insights into the nature and extent of the microplastic challenge.

This study investigated Enterobacteriales and their antimicrobial resistance in green sea turtles captured adjacent to the central Great Barrier Reef (GBR) and proximate to urban development. Cloacal swabs were taken from 73 green turtles between 2015 and 2016. A total of 154 out of 341 Gram-negative bacterial isolates were identified as Enterobacteriales that represent 16 different species from 9 different genera. The dominant isolates were Citrobacter (30.52%), Edwardsiella (21.43%) and Escherichia (12.34%). The resistance against 12 antibiotics belonging to 6 different classes was determined. The isolates showed highest resistance to β-lactam antibiotics (78.57%) followed by quinolone (50%) and tetracycline classes (46.1%). Approximately one-third (37.7%) of the isolates identified exhibited multidrug-resistance. Isolates recovered from rehabilitated turtles were significantly multidrug resistant (p<0.009) compared to isolates from other study sites. These results provide baseline information on antimicrobial resistance while revealing gaps for further research to evaluate the level of pollution in the GBR.

Ocean acidification is widely recognised to have a negative impact on marine calcifying organisms by reducing calcifications, but controversy remains over whether such organisms could cope with ocean acidification within a range of phenotypic plasticity and/or adapt to future acidifying ocean. We performed a laboratory rearing experiment using clonal fragments of the common branching corals Montipora digitata and Porites cylindrica under control and acidified seawater (lower pH) conditions (approximately 400 and 900μatm pCO2, respectively) and evaluated the intraspecific variations in their responses to ocean acidification. Intra- and interspecific variations in calcification and photosynthetic efficiency were evident according to both pCO2 conditions and colony, indicating that responses to acidification may be individually variable at the colony level. Our results suggest that some corals may cope with ocean acidification within their present genotypic composition by adaptation through phenotypic plasticity, while others may be placed under selective pressures resulting in population alteration.

The distributions of 15 nitrated polycyclic aromatic hydrocarbons (NPAHs) in sediments collected at 44 sites throughout Osaka Bay, Japan were examined. The highest total NPAHs, with a concentration of 1949ng/kg dry weight, were detected near the city of Amagasaki. Some sites near the cities of Osaka, Kishiwada, sand Sakai registered ng/kg levels of NPAHs, but individual NPAH concentrations were relatively lower than those in previous studies. The sources were estimated using principal component analysis, and NPAHs were derived from exhaust gases of automobiles and industries at some sites. However, our results suggest that it is difficult to estimate the source, especially in coastal areas near big cities and large industrial areas, because the generation pathways between parent polycyclic aromatic hydrocarbons (PAHs) and nitrated PAHs are slightly different, and the ratio of PAHs and NPAHs could not be accurately reflect the characters of sources in sediments especially at coastal areas with large-scale industrial zones.

The evolution of the impacts of anthropogenic activities in Todos os Santos Bay was evaluated by profiles of trace metals and Pb isotopes determined in sediment cores. Fluxes of metals increased up to 12, 4 and 2 times for Cu, Pb, and Zn, respectively, compared to those recorded in the beginning of the 20th century. Stable Pb isotopes identified a decommissioned lead smelter and burning of fossil fuels as the main sources of Pb. Most metals showed minor to moderate enrichment factors (EF<4), but Cu and Pb were highly enriched (EF=28 and 6, respectively) at the Aratu harbor. Temporal changes in sediments were associated to different activities, namely Pb smelting, burning of fossil fuels, maritime traffic, petroleum related activities, inputs of domestic effluents, and changes in land uses. The effects of the implementation of environmental policies to improve the waters of the bay could not be identified in the evaluated cores.

Using data from four periods from 1959 to 2015, we report the long-term variation of the macrobenthic community in the Yangtze River estuary and its adjacent area. In total, 624 species were collected, and Polychaeta was the dominant group. Significant differences between the four periods were found. The CCA (canonical correspondence analysis) and RDA (redundancy analysis) results revealed that temperature, salinity, and depth significantly influenced the macrobenthic communities (89.6% of the species-environment relationship variance was explained by the first two axes of CCA and 94.3% was explained by RDA). The results of K-dominance curves (the elevation increased over time), ABC (abundance/biomass comparison) curves (the W value changed from 0.311 to 0.167 during 1959 to 2014–2015) and the Shannon-Wiener index (log base=2; 2.29–5.03 in 1959, 2.86–4.55 in 2000–2001, 2.28–4.56 in 2011–2012, and 1.79–4.43 in 2014–2015) showed that the ecological status of the benthic study area was deteriorating.

Deltas provide many worthy ecosystem services. Yet, delta basins are quite vulnerable, especially in the face of climate change, which can affect the outcome of both agriculture and biodiversity. Moreover, rice paddy cultivation is well known to contribute with strong emissions of greenhouse gases (GHGs), such as methane (CH4). Thus, knowing the atmospheric variability of CH4 in relation to the different stages of the rice culture cycle could help to improve GHGs' mitigation strategies in deltas.The Ebro River Delta, in the northwestern Mediterranean basin, forms part of the largest Spanish river basin and is mainly covered by rice fields. In this study, for the first time, ground level (40 cm a.g.l.) atmospheric CH4 concentrations have been monitored in this area, through twenty-seven car mobile transects, over the course of one year. Seasonal, diurnal and spatial variability of CH4 concentrations were studied to identify its relationship with rice cultivation, meteorological conditions and land-use distribution.With regard to seasonal variability, autumn transects showed the highest mean values for atmospheric CH4 (2.466 ppm) when dead rice straw is mixed with the sediment, and weed growth is prevented. Spring and summer measurements gave the highest mean CH4 values at dawn (1.897–3.544 ppm), whereas autumn and winter produced the mean values after sunset (2.148–2.930 ppm). Spatial differences were accounted for by proximity to urban areas, presence of shallow water storage structures, and distance to seawater.

Liaodong Bay, a semi-enclosed bay located in northeastern China, is impacted by the discharges of five rivers. We analyzed 100 surface sediment samples from the Shallow Sea Wetland of Liaodong Bay for grain size and concentrations of organic carbon (Corg) and heavy metals. The ranges of the heavy metal concentrations were 2.32–17μg/g (As), 0.025–1.03μg/g (Cd), 18.9–131μg/g (Cr), 4.6–36.1μg/g (Cu), 0.012–0.29μg/g (Hg), 13.7–33.9μg/g (Pb), and 17.4–159μg/g (Zn). Pollution assessments revealed that some stations were moderately to highly polluted with As, Cd, and Hg. Severe pollution was apparent in the Xiaoling River estuary; lower concentrations of heavy metals were observed in other river mouths, where the sediments were more coarse. The distributions of the heavy metals were closely associated with Corg and grain size.