Estuaries are areas of both freshwater and seawater that are partially enclosed with contact to the open sea and a flow of fresh water. Although the Jiulong River Estuary has a relatively small catchment, this area was found to exhibit high nutrient fluxes. The nutrient fluxes showed obvious fluctuations for different years. The Jiulong River Estuary was predominantly P-limited, and was slowly moving towards higher DIN:DIP and DSi:DIP ratios as the nitrate concentrations increased. The high nutrient fluxes into the estuary may affect estuarine ecosystems by the alteration of DO concentrations in bottom waters, causing harm to benthic fauna due to a lack of oxygen, triggering algal blooms. Additionally, the Jiulong River Estuary was slowly moving towards lower DSi:DIN and DSi:DIP ratios along with the change of time scales, which caused nutrient limitation of phytoplankton growth as P and Si levels decreased and became more limiting.

We compared total mercury (Hg) concentrations in whole blood of harlequin ducks (Histrionicus histrionicus) sampled within and among two geographically distinct locations and across three years in southwest Alaska. Blue mussels were collected to assess correlation between Hg concentrations in locally available forage and birds. Mercury concentrations in harlequin duck blood were significantly higher at Unalaska Island (0.31±0.19 mean±SD, μg/g blood) than Kodiak Island (0.04±0.02 mean±SD, μg/g blood). We found no evidence for annual variation in blood Hg concentration between years at Unalaska Island. However, blood Hg concentration did vary among specific sampling locations (i.e., bays) at Unalaska Island. Findings from this study demonstrate harlequin ducks are exposed to environmental sources of Hg, and whole blood Hg concentrations are associated with their local food source.

Trends in oil rates of beached seabirds reflect temporal and spatial patterns in chronic oil pollution at sea. We analysed a long-term dataset of systematic beached bird surveys along the Belgian North Sea coast during 1962–2015, where extreme high oil contamination rates and consequently high mortality rates of seabirds during the 1960s used to coincide with intensive ship traffic. In the 1960s, >90% of all swimming seabirds that washed ashore were contaminated with oil and estimated oil-induced mortality of seabirds was probably several times higher than natural mortality. More than 50years later oil rates of seabirds have dropped to historically low levels while shipping is still very intense, indicating that chronic oil pollution has significantly declined. The declining trend is discussed in the light of a series of legislative measures that were enacted in the North Sea region to reduce oil pollution.

Fossil fuels, e.g. gasoline and diesel oil, account for substantial share of the pollution that affects marine ecosystems. Environmental metabolomics is an emerging field that may help unravel the effect of these xenobiotics on seaweeds and provide methodologies for biomonitoring coastal ecosystems. In the present study, FTIR and multivariate analysis were used to discriminate metabolic profiles of Ulva lactuca after in vitro exposure to diesel oil and gasoline, in combinations of concentrations (0.001%, 0.01%, 0.1%, and 1.0% - v/v) and times of exposure (30min, 1h, 12h, and 24h). PCA and HCA performed on entire mid-infrared spectral window were able to discriminate diesel oil-exposed thalli from the gasoline-exposed ones. HCA performed on spectral window related to the protein absorbance (1700–1500cm−1) enabled the best discrimination between gasoline-exposed samples regarding the time of exposure, and between diesel oil-exposed samples according to the concentration. The results indicate that the combination of FTIR with multivariate analysis is a simple and efficient methodology for metabolic profiling with potential use for biomonitoring strategies.

The effect of multiple stressors on marine ecosystems is poorly understood. To partially bridge this knowledge gap we investigated the relative contribution of environmental variables to density and diversity dynamics of the zooplankton community in the Belgian part of the North Sea. We applied multimodel inference on generalized additive models to quantify the relative contribution of chlorophyll a, temperature, nutrients, salinity and anthropogenic chemicals (i.e. polychlorinated biphenyls and polycyclic aromatic hydrocarbons) to the dynamics of calanoid copepod species in the Belgian part of the North Sea. Temperature was the only predictor consistently showing a high importance in all models predicting the abundances of the selected copepod species. The relative contribution of other predictors was species-dependent. Anthropogenic chemicals were important predictors for three out of six species indicating that chemical mixtures at low concentrations should not be left unattended when performing risk assessments in a natural environment.

The necessity of having a process in place for adequate risk assessment of shipwrecks that pose a threat to the marine environment is today internationally acknowledged. However, retrieving the desired data for such a risk assessment can prove challenging. One means of addressing this problem is to make use of experts' knowledge and experience. The purpose of this paper is therefore to present and analyse data for risk assessment of shipwrecks derived by expert elicitation. The main outcome is the experts' estimations of (i) the generic probability of an opening in a shipwreck due to the occurrence of a number of activities and (ii) estimations of the degree to which site-specific and wreck-specific indicators affect the probability of opening. Results show that the derived information is applicable in probabilistic shipwreck risk assessment and that the VRAKA framework now contains needed information for integrating generic and site-specific information using Bayesian updating.

The particulate material was fractionated into 5 size classes (>90μ, 50–90μ, 6–50μ, 1–6μ, and <1μ). DOP was analysed as easily (DOPh, DOPpa) and less easily hydrolysable compounds (DOPox). Based on Vmax, 94% of the high affinity AP activity was due to <50μ cells and 77% to <1μ cells. 83% of the low affinity activity was due to >90μ cells. The high affinity activities were negatively correlated with DOP for the <50μ classes. These correlations came mostly from DOPox. They were more significant when NO3+NO2 concentrations were high, when DIP concentrations were low and when N/P ratio was >10. At lower N/P ratios, AP was more significantly correlated with DIP. The low affinity activities showed significant negative correlation with DIP and with DOP and DOPox for the >90μ class. The inhibition of AP activities by DOPox may originate from stable compounds interfering with DIP for the control of AP synthesis.

The aim of the present study is to optimize the slow release biostimulant ball (BSB) for bioremediation of contaminated coastal sediment using response surface methodology (RSM). Metals contamination and stabilization of metals in coastal sediments using BSB were investigated. The effects of BSB size (1–5cm), distance (1–10cm), and time (1–4months) on the stabilization of metals including Fe, Cd, Cu, and Pb were determined. The maximum stabilization percentages of Fe, Cd, Cu, and Pb, of 64.5%, 54.9%, 63.8%, and 47.6%, respectively, were observed at a 3cm ball size, 5.5cm distance, and a period of 4months; these values are the optimum conditions for effective treatment of contaminated coastal sediment. The determination coefficient of the R2 value suggests that >91.55%, 89.97%, 96.10%, and 86.40% of the variance is attributable to the variables of Fe, Cd, Cu, and Pb, respectively.

Failure of the Bay Park Sewage Treatment Plant (STP) during Superstorm Sandy led to adverse effects in the waters of Hempstead Bay, Long Island, NY. These appear to be related to large discharges of partially treated sewage through its primary and auxiliary outfalls. Modeled dilution discharges indicate that sewage infiltrated the bay, remaining up to 10days. Water column impacts included salinity and dissolved oxygen declines, and biological oxygen demand and nitrogen concentration increases. While the STP does not appear to have released fecal coliform, there were elevated levels of enterococci within the bay for a considerable period following the storm, probably from multiple sources.The STP's reduced functioning and associated environmental impacts, even with resilience upgrades, are not conducive to removing the bay from the list of Impaired Water Bodies. The results reinforce the need to transfer the discharge from the existing outfall to the ocean.