Stormwater is a challenging source of coastal pollution to abate because stormwater also involves complex natural processes, and differentiating these processes from anthropogenic excesses is difficult. The goal of this study was to identify the natural concentrations of stormwater constituents along the 1377km coastline of California, USA. Twenty-eight ocean reference sites, a priori defined by lack of human disturbance in its adjacent watershed, were collected following 78 site-events and measured for 57 constituents and toxicity. Results indicated a complete lack of toxicity and undetectable levels of anthropogenic constituents (i.e., pesticides). The range of concentrations in ocean receiving waters for naturally-occurring constituents (i.e., total suspended solids, nutrients, trace metals) typically ranged three orders of magnitude. Regional differences and storm characteristics did not explain much of the variations in concentration. The reference site information is now being used to establish targets for marine protected areas subject to runoff from developed watersheds.

The aim of the present study was to determine the antibiotic resistance patterns and distribution of heavy-metal resistance in Shewanella putrefaciens strains isolated from shellfishes collected from West Sea; and to determine the relationship, if any, between antibiotic and heavy-metal resistance in these strains. Among the 15 strains isolated, two strains, SY1 and SY2, showed heavy-metal resistance in addition to high resistance to seven antibiotics: cephalothin, gentamicin, erythromycin, vancomycin, ampicillin, rifampicin, and streptomycin. We conclude that heavy-metal contamination imposes long-term, widespread, and recalcitrant selection pressure, which potentially contributes to the maintenance and spread of antibiotic resistance factors in bacteria. Moreover, this fact holds both environmental and clinical importance.

This study aims to evaluate the nutrient removal potential and carrying capacity of green mussel cultivation by using the mass balance model. The developed model takes into consideration the green mussel growth rate, density and chlorophyll a concentration. The data employed in this study were based on culture conditions at Sriracha Fisheries Research Station, Thailand. Results show that net nutrient removal by green mussel is 3302, 380, and 124mg/year/indv for carbon, nitrogen, and phosphorus respectively. The carrying capacity of green mussel cultivation was found to be 300indv/m2 based on chlorophyll a concentration which will not release phosphorus in the water environment beyond the standard (45μg-PO4−3-P/L). Higher chlorophyll a concentration results in lowered green mussel carrying capacity. This model can assist farm operators with possible management strategies for a sustainable mussel cultivation and protection of the marine environment.

Based upon surveys conducted in November 2012 and June 2013, the distribution and dynamics of aragonite saturation state (Ωarag) were investigated in the southern Yellow Sea (SYS) of China. In summer, surface water Ωarag ranged from 2.1–3.8 and enhanced biological production fueled by Changjiang River freshwater input increased Ωarag to 3.8 in the southern SYS. However, subsurface water Ωarag was <2.0 in the central SYS. During autumn, surface water Ωarag was 2.0–2.9, lower than that in summer due to ventilation between surface and low Ωarag (1.0–1.4) subsurface waters in the central SYS. Community respiration and/or aerobic remineralization dominated low Ωarag in subsurface waters, while water stratification influenced the level and scale of acidity accumulation. By the end of this century, waters with Ωarag>2.0 could disappear from the SYS with increasing atmospheric CO2, while bottom waters Ωarag may become undersaturated due to the impact of eutrophication.

Concentrations of 15 polycyclic aromatic hydrocarbons (PAHs) in air–seawater interface were measured over 1year in the coastal region of Incheon, South Korea. Most individual PAHs and total PAHs in air displayed statistically significant negative correlations with temperature, but not significant in seawater. Less hydrophobic compounds with three rings were at or near equilibrium in summer, while PAHs with four to six rings were in disequilibrium in all seasons, with higher fugacity gradients in colder seasons and for more hydrophobic compounds. Differently from fugacity gradients, the highest net fluxes occurred for some three- and four-ring PAHs showing the highest atmospheric concentrations. Net gaseous exchange, which was higher in winter, occurred from air to seawater with an annual cumulative flux of 2075μg/m2/year (for Σ15PAHs), indicating that atmospheric PAHs in this region, originating from coal/biomass combustion, can deteriorate the quality of seawater and sediment.

Some barrier-island dunes damaged or destroyed by Hurricane Sandy's storm surges in October 2012 have been reconstructed using sediments dredged from back bays. These sand-, clay-, and iron sulfide-rich sediments were used to make berm-like cores for the reconstructed dunes, which were then covered by beach sand. In November 2013, we sampled and analyzed partially weathered materials collected from the cores of reconstructed dunes. There are generally low levels of metal toxicants in the reconstructed dune materials. However oxidation of reactive iron sulfides by percolating rainwater produces acid-sulfate pore waters, which evaporate during dry periods to produce efflorescent gypsum and sodium jarosite salts. The results suggest use of sulfidic sediments in dune reconstruction has both drawbacks (e.g., potential to generate acid runoff from dune cores following rainfall, enhanced corrosion of steel bulwarks) and possible benefits (e.g., efflorescent salts may enhance structural integrity).

Semicarbazide (SEM), an industrial raw material and the marker residue of nitrofurazone as a veterinary drug, has become a new type of marine pollutant. A standard method (ultra-performance liquid chromatography–tandem mass spectrometry, UPLC–MS/MS) was used to analyze SEM in seawater, sediment, and shellfish. A series of sections and stations were set up in radical distribution in western Laizhou Bay, with six voyages and 150 monitoring samples. The concentrations of SEM in seawater and shellfish were 10−11 and 10−10kg/L, respectively, and no SEM was detected in the sediment. Distribution characteristics at each state, temporal and spatial trends, multivariate analyses, and the causes were analyzed to assess the pollution level, which aimed to offer a database for drafting the national baseline values of SEM in seawater and sediment in future. The data obtained could be used for integrated watershed management of marine environment and economic activities for constructing a blue economic zone of Shandong Peninsula in China.

A high selective pre-treatment method for the cleanup and preconcentration of ciprofloxacin in natural seawater samples was developed based on molecularly imprinted solid-phase extraction (MISPE). The ciprofloxacin imprinted polymers were synthesized and the characteristics of obtained polymers were evaluated by scanning electron microscopy, Fourier transform infrared spectroscopy and binding experiments. The imprinted materials showed high adsorption ability for ciprofloxacin and were applied as special solid-phase extraction sorbents for selective separation of ciprofloxacin. An off-line MISPE procedure was optimized and the developed MISPE method allowed direct purification and enrichment of the ciprofloxacin from the aqueous samples prior to high-performance liquid chromatography analysis. The recoveries of spiked seawater on the MISPE cartridges ranged from 75.2 to 112.4% and the relative standard deviations were less than 4.46%. Five seawater samples from Jiaozhou Bay were analyzed and ciprofloxacin was detected in two samples with the concentrations of 0.24 and 0.38μgL−1, respectively.

Three core samples were taken from zones offshore from the Mejerda River Delta (Tunisia) and analyzed for major and trace elements to assess their relationships with organic matter, monosulfides and carbonates, as well as for pollution and bioavailability. Chemical speciation, ∑ SEM/AVS, the enrichment factor (EF) and the geo-accumulation index (I-geo) were used. Iron, cadmium, lead and zinc – the most frequently mined metals in the Mejerda catchment – were found as contaminants in the offshore areas. Estimations of trace element accumulation using the EF and the I-geo index show that lead, and to a lesser extent zinc, are the most polluting metals off the Mejerda outlet. According to their bioavailability, these metals are also the most toxic. Only cadmium is heavily present in delta sediment (EF>100) though deeply sequestrated (100% bound to the residual fraction) and thus presents no toxicity.

Identifying environmental damage due to anthropogenic activities is a focal point for scientists and policy makers like those involved in the European Water Framework Directive (WFD). Many of these approaches focus on ecological endpoints for assessing environmental perturbations, which lead to policies emphasizing mitigation rather than prevention. Biomarkers provide early-warning indicators of stress but it is necessary to distinguish their natural variations from those induced by chemical stress. The global aim of this study was to establish a baseline assessment criterion (BAC) using historical data in a reference site to define toxicity thresholds. We have developed a multiple polynomial regression model (MPR) accounting the influence of salinity, temperature and size of individual on energetic reserves (glycogen and lipids) in the marine polychaete Hediste diversicolor. The model identified a complex, orthogonal relationship between confounding factors and glycogen and a linear relationship between lipids and size of individuals.