Ocean-going ships are mostly driven by high‑sulfur heavy fuel oil, which poses public health and environmental concerns. Emission control areas (ECA) have been developed for the regulatory control of the sulfur content in fuel. We tracked 28 sample vessels that entered and exited Shanghai Port, to understand how air pollutants, including oxysulfides (SOx), nitric oxide (NOx), and particulate matter smaller than 10 μm (PM₁₀), would change under the ECA regulations. Emission reductions vary with the types and sizes of the ships. In our sample pool, oil/chemical tankers and container ships have the highest decline rates of SOx emissions at 26.8%–56.4% and 17.4%–56.6%, respectively. Cruise ships, container ships, and liquefied gas carriers occupy the highest share ratios of pollutant emissions in the sample pool because of the higher average gross tonnage and correspondingly higher-rated power of the ships' main engines. As expected, SOx and PM₁₀ emissions under hoteling conditions (operations while stationary at dock) can be considerably reduced by switching to low-sulfur fuel. Using fuel with the much lower sulfur content of 0.1% m/m in the ECA, the SOx and PM₁₀ emissions of our sample pool could be reduced considerably by up to 94.4% and 78.3%, respectively, compared to the 0.5% m/m sulfur content used during ship hoteling.

Pollution by microplastics and antibiotics is an emerging environmental, human and animal health threat. In spite of several studies documenting the widespread occurrence of plastic debris in aquatic ecosystems, research focusing on occurrence and concentration of biological and chemical contaminants attached on microplastic surface as well as on possible interactions of these contaminants with microplastics is still at its beginning. The present note addresses the role of microplastics as vectors of contaminants in water bodies, stressing the need for future investigations on this hot topic.

18 polycyclic aromatic hydrocarbons (PAHs) were evaluated in the Jaguaribe River to explore the influence of grain size, organic carbon, humic and fulvic acids and black carbon on their adsorption onto sediment. The ∑PAHs concentrations variated from 0.6 to 3752.0 ng g⁻¹ with highest concentrations in the estuarine zone. The PAHs predominant source along the river was from mixed sources, mainly related to biomass combustion, small oil spills related to recreational nautical activities and runoff from cities. Organic and inorganic parameters presented influence on PAHs distribution along the river, with humic acid as a determinant factor. These research findings are of importance to an assessment of the fate and transport of PAHs in estuarine systems.

The Adriatic Sea is considered as a hotspot of marine biodiversity but, due to intense human activities (e.g. maritime transport, mariculture), it is also a recipient area of non-indigenous species (NIS). This study analyzed the scientific literature on non-indigenous macrophytes (NIM) recorded in ports, marinas and transitional waters (TWs) of the Adriatic Sea, in the period 1987–2018. The results show that 51 out of 118 Mediterranean NIM are found in Adriatic ports and TWs. The Venice Lagoon is the main Adriatic recipient area of NIM. Mariculture is the main vector of introduction, whereas the principal pathways of NIM dispersal are shipping and shellfish transfer. The largest group of NIM is of temperate northern Pacific origin. This study corroborated the fact that ports and TWs act as dispersal hubs and invasion hotspots. The importance of early detection of NIM at such sites should be considered in any environmental management strategy.

With the recovery of whale populations, carcass strandings on beaches are growing. Beach burial is a common management option for stranded carcasses. However, communities fear shark attraction following leachate transport to the ocean via submarine groundwater discharge. Here, a sediment column mesocosm experiment indicated that carcasses can be a localised source of dissolved organic carbon (DOC), phosphate and ammonium to groundwater. The spatial reach of the leachate plume was <2.5 m, while the temporal stabilisation occurred over 100–300 days. No significant chemical signals were observed under a beach-buried carcass, implying effective attenuation of decomposition plumes. For beaches with conditions similar to our one-directional, fast-flowing sediment experiment generating extreme groundwater contamination, it is unlikely that any leachate from a whale carcass would reach the ocean if buried >25 m onshore. Therefore, carcass leachate plumes would only potentially attract sharks to the surf under specific conditions not experienced during our experiments.

Effective site selection is a key component of maximising debris removal during coastal cleanup actions. We tested a GIS-based predictive model to identify marine litter hotspots in Lofoten, Norway based on shoreline gradient and shape. Litter density was recorded at 27 randomly selected locations with 5 transects sampled in each. Shoreline gradient was a limiting factor to litter accumulation when >35%. The curvature of the coastline correlated differently with litter density at different spatial scales. The greatest litter concentrations were in small coves located on larger headlands. A parsimonious model scoring sites on a scale of 1–5 based on shoreline slope and shape had the highest validation success. Sites unlikely to have high litter concentrations were successfully identified and could be avoided. The accuracy of hotspot identifications was more variable, and presumably more parameters influencing litter deposition, such as shoreline aspect relative to prevailing winds, should be incorporated.

This study focuses on the ecological health assessment of Chilika, a shallow lagoon present in east coast of India, through nutrient stoichiometry and trophic state index (TSI). Multivariate statistical analysis such as ANOVA, Pearson's correlation, Principal Component Analysis (PCA), and Discriminant Analysis (DA) were employed for data interpretation. Nutrient stoichiometry revealed that the Chilika Lagoon experiences phosphorus limitation with regard to nitrogen and silicate (N:P:Si = 16:1:16) throughout the study period. As per the computed TSI values, the southern sector (SS), central sector (CS), and outer channel (OC) were assigned with a mesotrophic status, whereas the northern sector (NS) was assigned with the eutrophic status. From PCA, total nitrogen was found to be negatively correlated with salinity and positively correlated with silicate, thus indicating that the major source of nitrogen in the lagoon was freshwater ingress by rivers with high silicate content. DA indicated that it was successful in discriminating the groups as predicted.

The beaches of Goa state in India are frequently polluted with tarballs, specifically during pre-monsoon and monsoon seasons. Tarballs contain hydrocarbons, including polycyclic aromatic hydrocarbons, which pose significant environmental risks. Microbes associated with tarballs reportedly possess capabilities to degrade toxic hydrocarbons present in tarballs. In this study, bacterial diversity associated with tarballs from Vagator and Morjim beaches of north Goa was analysed based on V3–V4 regions of 16S rRNA gene sequenced using Illumina Miseq Platform. The Proteobacterial members were dominant in both Vagator (≥85.5%) and Morjim (≥94.0%) samples. Many of the identified taxa have been previously reported as hydrocarbon degraders (e.g. Halomonas, Marinobacter) or possible human pathogens (e.g. Acinetobacter, Klebsiella, Rhodococcus, Staphylococcus, Vibrio). This is the first study reported on a metagenomic analysis of bacteria associated with tarballs from Goa.