Macrozoobenthos living around several pipelines placed at different depths and sediment types in the Western Adriatic Sea was investigated for three years after structures' deployment to detect possible effects due to their installation and presence. Three environmental habitats were considered based on the grain size (silty clay, clayey silt and sand). Samplings were taken within a radius of 100 m from the pipelines and at control sites. Multivariate and univariate analysis showed peculiarities of the three habitats due to the different sediment type, without differences between pipelines and controls inside each group. Silty clay and clayey silt communities appeared quite similar, being mainly represented by opportunistic species typical of the Adriatic coastal area. Benthic populations found at the offshore relict sand were characterized by a higher percentage of sensitive species. Independently of sediment typology, pipelines' installation seems to not affect the benthic populations that appear more influenced by environmental features.

Pot fisheries occur worldwide with a significant proportion of the gear becoming derelict. Derelict pots induce detrimental ecological and economic impacts, and more recently were found to reduce blue crab harvests in the Chesapeake Bay commercial fishery. We simulated the presence of derelict pots near actively fished pots in seasonal field experiments to quantify the effect derelict pots have on blue crab harvest. Derelict pots reduced harvests by 30% during the summer, but not during the fall. Female blue crab capture rates were consistently lower when derelict pots were present; while capture rates of the less abundant males were not negatively affected by derelict pots. Variable responses to derelict pots may be due to seasonal differences in female and male blue crab behavior and movements. The costly effect that derelict pots have on harvest should be investigated in other pot fisheries to recognize the magnitude and mechanisms behind these impacts.

A cliff-face disposal system discharging approximately 940 ML/day, or 80% of sewage generated by the City of Sydney (Australia) (population 3.3 million) was replaced by three deepwater ocean outfalls in the early 1990s. Enrichment of anthropogenic chemicals from cliff-face discharges raised concerns regarding long-term accumulation of sewage particulates and associated contaminants in offshore sediments and for reduced beach water quality. The current post-commissioning investigation detected a southward gradient of sediment fining and increased total organic carbon in the study region. Deepwater ocean discharges have not contributed to an accumulation of fines, or to increased metallic/nonmetallic chemicals of concern with no elevated risk of adverse biological effects beyond pre-commissioning conditions. Instead, the best modelled relationship was recorded between benthic infauna and sedimentary fines and not to contaminants. Historic sea dumping prior to 1932 in the north of the study area has resulted in enrichment of some non-bioavailable sedimentary metals.

Stable isotopes and geochemical proxies (TOC/TN and Chla/TOC) in sediments can be used to distinguish organic matter sources (anthropogenic, terrestrial, or marine). This study aims to characterize organic matter (OM) in superficial sediments from three sectors of central Chile (33°S) that are highly influenced by urban and industrial development. Our results show that a substantial fraction of these OM in Quintero Bay is anthropogenic, from industrial and domestic wastewater sources. In contrast, a mixture of terrestrial and anthropogenic OM dominates the isotopic signal of surface sediments from Concón, derived from non-point industrial and agriculture sources associated with the Aconcagua River basin, while Ritoque exhibited a mixture of different OM sources. However, deposition of allochthonous OM in our study area depends on coastal topography, which influences the local currents and well-ventilated waters, promoting the dispersion and assimilation of OM and thus providing an environment with a high capacity for natural remediation.

Polychlorinated biphenyls (PCBs) found in marine molluscs could be a serious threat to the health of consumers; however, studies on this subject are limited. To understand this threat, the indicator PCBs (PCB-28, PCB-52, PCB-101, PCB-118, PCB-138, PCB-153 and PCB-180) found in six different kinds of molluscs were determined, and the associated cancer risk for consumers that intake these indicator PCBs via molluscs was assessed. The total concentrations of PCBs in molluscs ranged from 17.51 to 47.43 ng/g (d.w.). The order of contamination levels for indicator PCBs in molluscs was Perna viridis > Ruditapes philippinarum > Crassostrea gigas > Mimachlamys nobilis > Glossaulax didyma > Anadara antiquata. Tri-, tetra- and penta-PCBs were the dominant congeners in molluscs from Haikou City. Tetra-PCBs are the most common PCB, accounting for 38.49% of total PCBs. Compared with previous global studies on PCBs in molluscs, the pollution level of indicator PCBs in the molluscs from Haikou City was lower than most of reports in Europe and China, but higher than those from France and Korea, suggesting a moderate pollution level. The 50% and 95% cancer risks of indicator PCBs in molluscs for adult consumers were 2.75 × 10−7 and 4.32 × 10−7, indicating that the cancer risk was at an acceptable level. Since the dioxin like-PCBs were not analyzed in this study, the cancer risk of PCBs to human health might be underestimated; therefore, more studies on PCB pollution in molluscs are required.

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.

This is the first study on polychlorinated biphenyls (PCBs) in fish from the Cau Hai lagoon, a part of the largest coastal lagoon in Southeast Asia. Seven selected PCB congeners and organochlorine pesticides in sediments and edible fish tissues were quantified by GC–MS. The sum of ICES-7 PCB and DDTs concentrations in fish species consumed regularly and of economic value were in ranges 26–43 ng g−1 lw and 182–277 ng g−1 lw, respectively. The ratio between the parent DDT compound and the sum of metabolites, DDE and DDD, was most of the time smaller than 1, suggesting primarily an historical contamination of the lagoon. An agglomerative hierarchical clustering indicates sites located in the north-western part of the Cau Hai lagoon were characterized by above-average concentrations of DDE and DDT. Comparing to previous data, a large decrease in ∑DDT residues can be seen over the past 20 years.

Concentrations of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were determined in surface sediment from five estuaries of central coasts of Vietnam to understand the spatial distributions and seasonal variations. The contamination pattern was in the order: PCBs (9.72–3730 ng g⁻¹ dry wt.) > PBDEs (11.8–311 ng g⁻¹ dry wt.) > DDTs (0.462–26.7 ng g⁻¹ dry wt.) > HCHs (0.491–22.6 ng g⁻¹ dry wt.) > endosulfan compounds (0.196–19.4 ng g⁻¹ dry wt.). DDTs and HCHs showed a little geographical variation, whereas PCBs and PBDEs exhibited clearer spatial distribution trend. Elevated concentrations of PCBs and PBDEs were detected in some sites in Nghe An and Quang Binh Province, which could be related to the human activities such as tourism, transportation, and domestic consumption. Seasonal variations of DDTs and HCHs were observed, showing higher residues in rainy seasons.

The extent of the Earth’s surface burned annually by fires is affected by a number of drivers, including but not limited to climate. Other important drivers include the amount and type of vegetation (fuel) available and human impacts, including fire suppression, ignition, and conversion of burnable land to crops. Prior to the evolution of hominids, area burned was dictated by climate via direct influences on vegetation, aridity, and lightning. In the future, warming will be accompanied by changes in distribution, frequency, intensity, and timing of precipitation that may promote or suppress fire activity depending on location. Where area burned increases, fire may become self-regulating by reducing fuel availability. The effects of climate change on fire regimes will be strongly modulated by humans in many areas. Here, we use a systems approach to outline major drivers of changes in area burned. Due to the array of interacting drivers working in concert with climate’s influence on burned area, and uncertainty in the direction and magnitude of changes in these drivers, there is very high uncertainty for much of the globe regarding how fire activity and accompanying smoke emissions will change in the coming decades.

Microplastic distribution in waters gained increasing attention because of the discovery of microplastics in edible marine organisms. Microplastic size is small, and hence, it tends to float in the water column, thereby making it easy to enter and accumulate in the marine organism. Microplastic abundance is highly associated with the population density. The North Coast of Surabaya is the main area for community activities in East Java; therefore, it is highly vulnerable to receive microplastic input from the mainland. This study aimed to analyze the abundance, distribution, and characteristics of microplastics in the northern coastal waters of Surabaya. The study was conducted in March 2017. The results showed that the highest and lowest microplastic abundances were found in Lamong Bay. The microplastic characteristics in all stations showed that foam was the dominant form and polystyrene was the dominant type, with sizes of 500–1000 μm and 300–500 μm.