We assess how different micropollutants and microplastics, connected to wastewater are introduced into the Baltic Sea. The relevance of untreated wastewater, treated wastewater, treated and untreated rain runoff, as well as combined sewer overflow (CSO), is assessed in respect to mass balance, as well as relative inflows of micropollutants and -plastics into the Baltic Sea. To achieve this, modelling based on data on exemplary sewer systems and measured micropollutant concentrations in the single sources were used. Most compounds reach the receiving Baltic Sea via treated wastewater. A few exceptions are compounds that are removed to a very high extent in wastewater treatment plants. For these compounds, the emissions with stormwater (e.g., terbutryn) or untreated wastewater (e.g., triclosan) are dominating. Additionally, compounds that are discharged with the water that is running off urban surfaces are introduced into marine areas via rain runoff. These data are used to forecast a total mass load and concentrations that can be expected in the Baltic Sea. Massloads are expected to be between 0.1 and 5.9 t/a for triclosan and TCPP (tris (2-chloropropyl) phosphate) and 0.2 t/a for microplastic particles. The expected concentrations in open Baltic Sea waters range from 0.01 to 26 ng/L.

Coastal litter abundance and its effects have increased for years. Waste reduction is the most effective countermeasure to fight against this problem. Littering attitudes may have an effect on people's involvement in coastal cleanups. In this study, coastal litter perception, awareness about its impact and likely sources were investigated in local population from south Bay of Biscay, Spain. People of different age groups and commitment levels regarding litter were interviewed and their answers compared with data from the area. Results showed differences in perception between volunteers and non-volunteers, but not between children and adults. Interaction effect of age was found for awareness. Volunteers and children tended to erroneously attribute the main litter origin to beachgoers, more than non-volunteers or adults. Our results suggest that encouraging local population to clean beaches would contribute to improve their perception of the problem and their attitudes toward taking action.

Metals, whether essential (Cu, Zn, Cr, Fe, Mn) or non-essential (Al, As, Cd, Ni, Pb, Hg) for organism metabolism, occur naturally in the marine environment and their abundance can increase due to the presence of human activities. In this study, fish were used as bio-indicators, to determine a correlation between the bio-accumulation of metals in muscle and gill tissues and the health status of fish. The study area was the Gulf of Tigullio (north-western Italy), which is impacted by various sources of metal contamination. Histopathology served as a significant tool to investigate possible alterations in gills, one of the main organs involved in fish physiology. Results highlighted some correlations between certain metals (e.g. Pb, Ni) and gill alterations (e.g. epithelial hyperplasia, epithelial lifting), providing baseline data from a pool of different fish species, which can be used for comparison purposes in further studies.

This study examines how dissolved oxygen (DO) responds to tropical cyclones (TCs) "Wind Pump" in a pre-existing cyclonic and an anticyclonic eddy over the Bay of Bengal (BoB) based on Argo and satellite data. Both TCs induced DO temporal decreases in the subsurface waters (Deep Depression BOB 04 with a pre-existing cyclonic eddy and cyclonic storm Roanu with a pre-existing anticyclonic eddy) owing mainly to the storm-induced upwelling. The deeper oxycline caused by the pre-existing anticyclonic eddy relieved the storm-induced shallow of oxycline during Roanu. On the contrary, the pre-existing cyclonic eddy shoaled the oxycline, intensifying the storm-induced shallow of oxycline during BOB 04. Furthermore, the pre-existing cyclonic eddy induced a long time of DO decrease after BOB 04. This study suggests that the subsurface DO concentrations in the BoB are affected mainly by storm-induced physical processes, and the mesoscale eddies also play an important role.

The distribution, composition, potential sources and ecological risk of 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) were investigated in surface water from coastal Bohai Bay. The PAH concentrations ranged from 48.0 to 607 ng L⁻¹ with the mean value of 267 ng L⁻¹ in dissolved phase and 198 to 935 ng L⁻¹ with the mean value of 424 ng L⁻¹ in particle-associated phase, and decreased following the order: Qinhuangdao (QHD) > Caofeidian (CFD) > Huanghuagang (HHG). The 2–3 ring PAHs accounted for 79.9% to 86.2% in particle-associated phase and 65.6% to 73.2% in dissolved phase of total 16 PAHs, in which naphthalene (Nap) was the most dominant compound. The PAHs in surface seawater mainly originated from petrogenic sources according to the molecular ratios of benzo[a]anthracene/228 and fluoranthene/202. Risk quotients indicated that there was potential ecological risk for PAHs in surface seawater, especially for pyrene and fluorene.

To examine whether historical fish bones can record the magnitude of heavy metal pollution, we analyzed up to 700 years old fish bone remains extracted from an ornithogenic sediment profile on Nandao Island, South China Sea. Bulk sediments and subfossil fish bones were analyzed for elemental and mineralogical composition, as well as stable carbon and nitrogen isotopes. The results showed that pre-1850 CE fish bones experienced significant diagenesis, and could not be used to reconstruct historical record of heavy metal pollution. Fish bone diagenesis was mainly attributed to the erosion from guano in sediment profile. In contrast, the fish bones from in post-1850 CE time were well preserved and could provide useful information on historical pollution loads over the past 160 years. Since 1850 CE, relatively high concentrations of heavy metals from anthropogenic sources, especially Zn, were recorded in fish bone subfossils on Nandao Island, South China Sea.

The strategic location of Malaysia along the world's busiest trade waterways underscores the need to cope ballast water issues for both domestic and international shipping. The adoption of Ballast Water Management Convention 2004 (BWMC) by the International Maritime Organization is suitable for management plans intended to prevent the introduction of invasive species through ballast water discharge. Malaysia has ratified the BWMC in September 2010 and the Convention has come into force in September 2017. However up to now, the BWMC has not been fully implemented by Malaysia for ships operating in its waters. This paper analyse the headway in implementing the provisions of the BWMC in Malaysia as well as the issues and challenges encountered for the implementation. The paper concludes that Malaysian government should promulgate laws and policies to clearly communicate on ballast water issues to the shipping industry communities.

Past major oil spill disasters, such as the Prestige or the Deepwater Horizon accidents, have shown that spilled oil may drift across the ocean for months before being controlled or reaching the coast. However, existing oil spill modelling systems can only provide short-term trajectory simulations, being limited by the typical met-ocean forecast time coverage. In this paper, we propose a methodology for mid-long term (1–6 months) probabilistic predictions of oil spill trajectories, based on a combination of data mining techniques, statistical pattern modelling and probabilistic Lagrangian simulations. Its main features are logistic regression modelling of wind and current patterns and a probabilistic trajectory map simulation. The proposed technique is applied to simulate the trajectory of drifting buoys deployed during the Prestige accident in the Bay of Biscay. The benefits of the proposed methodology with respect to existing oil spill statistical simulation techniques are analysed.

In this study, the fate of residual oils was investigated during remediation activities for a year after the Wu Yi San oil spill. Microscope observations showed that relatively large amounts of oil-suspended particulate matter aggregate (OSA) were formed. Negatively buoyant OSA was the dominant form (>95%), followed by neutrally (~5%) and positively buoyant (<1%) forms. To elucidate the dominance of negative buoyancy OSA, physicochemical properties of the mineral and residual oils were identified. Chemical analysis showed that the weathering percentage of residual oils was 43.7 ± 2.59%, which was the driving factor for sedimentation of OSA. As the density of oil increased with weathering stages, the density of OSA also increased simultaneously. These results showed that, during mechanical remediation activities, resurfaced residual oils can form negative buoyancy OSA which tends to sink and transfers oil contaminants from intertidal to benthic environments.

Research on marine microplastics continues to increase in popularity, with a large number of studies being published every year. However, with this plethora of research comes the need for a standardised approach to quantification and analysis procedures in order to produce comparative assessments. Using data collected from neuston nets in 2016, parameters for quantifying microplastics were compared. Surface area was the most accurate parameter to describe plastic size and should be used to describe plastic quantity (per km2 or m3), alongside abundance. Of the two most commonly used methods for calculating plastic concentration (flowmeter and ship's log), ship's log provided consistently smaller abundances, with the exception of one sample, calling for a standardisation in the techniques and measurements used to quantify floating microplastics.