Can dust and tarry substances that are rich in polycyclic aromatic hydrocarbons (PAHs), which are deposited on leaves, cause changes in the water retention of tree crowns? It is hypothesized that the contact angle between droplets and a leaf's surface and water capacity changes because of the content of PAHs. This angle is treated as a bioindicator of environmental pollution. The goal of this study was to analyse the relationship between rainfall water capacity and wettability of small-leaved lime and poplar in different zones in a city centre during the period from April through November. We implemented a series of simulated rainfall and angle measurements under laboratory conditions of tree twigs collected at three locations inside the city centre and one from an area outside the city. The background for the water capacity values were results acquired from selected PAHs contents determined in leaves using high-performance liquid chromatography (HPLC), and images of the leaves' surface were acquired via Scanning Electron Microscope (SEM). Based on the obtained results, we concluded that there were significant differences in water capacity between the areas for each month. In the city centre, water capacity from April to July was lower than that in the forested area. From July to the end of the growing season, the water capacity was lower in the city compared to the forest area. The contact angle was strongly correlated with water capacity. With a decreasing contact angle, the raindrops increasingly adhered to the leaf surface, and water capacity increased. It was found that the effects of pollution on water capacity cannot be ignored in developing forecasts or in models describing ecosystem and hydrological changes in natural and urbanized environments. | Contact angle, Polycyclic aromatic hydrocarbons (PAHs), SEM, Water balance | 20 | 455-463 | 3

Water quality has recently emerged as one of the utmost severe ecological problems being faced by the developing countries all over the world, and Bangladesh is no exception. Both surface and groundwater sources contain different contaminants, which lead to numerous deaths due to water-borne diseases, particularly among children. This study presents one of the most comprehensive reviews on the current status of water quality in Bangladesh with a special emphasis on both conventional pollutants and emerging contaminants. Data show that urban rivers in Bangladesh are in a critical condition, especially Korotoa, Teesta, Rupsha, Pashur, and Padma. The Buriganga River and few locations in the Turag, Balu, Sitalakhya, and Karnaphuli rivers have dissolvable oxygen (DO) levels of almost zero. Many waterways contain traces of NO3, NO2, and PO4-3 pollutants. The majority of the rivers in Bangladesh also have Zn, Cu, Fe, Pb, Cd, Ni, Mn, As, and Cr concentrations that exceed the WHO permissible limits for safe drinking water, while their metal concentrations exceed the safety threshold for irrigation. Mercury poses the greatest hazard with 90.91% of the samples falling into the highest risk category. Mercury is followed by zinc 57.53% and copper 29.16% in terms of the dangers they pose to public health and the ecosystem. Results show that a considerable percentage of the population is at risk, being exposed to contaminated water. Despite hundreds of cryptosporidiosis cases reported, fecal contamination, i.e., Cryptosporidium, is totally ignored and need serious considerations to be regularly monitored in source water.

High fertilizer input is necessary to sustain high yields in oil palm agroecosystems, but it may endanger neighboring aquatic ecosystems when excess nutrients are transported to waterways. In this study, the hydrochemical dynamics of groundwater and streams under baseflow conditions were evaluated with bi-monthly measurements for 1 year on 16 watersheds. Hydrochemical measurements were related to the spatial distribution of soil and fertilization practices across a landscape of 100 km2, dominated by oil palm cultivation, in Central Sumatra, Indonesia. The low nutrient concentrations recorded in streams throughout the landscape indicated that the mature oil palm plantations in this study did not contribute to eutrophication of aquatic ecosystems. This was ascribed to high nutrient uptake by oil palm, a rational fertilizer program, and dilution of nutrient concentrations due to heavy rainfall in the study area. Soil type controlled dissolved inorganic N and total P fluxes, with greater losses of N and P from loamy-sand uplands than loamy lowlands. Organic fertilization helped to reduce nutrient fluxes compared to mineral fertilizers. However, when K inputs exceeded the oil palm requirement threshold, high K export occurred during periods when groundwater had a short residence time. For higher nutrient use efficiency in the long term, the field-scale fertilizer management should be complemented with a landscape-scale strategy of fertilizer applications that accounts for soil variability. (Résumé d'auteur)

Marine debris (MD) can be a transport vector for diverse marine communities, including non-indigenous species (NIS). This study assessed MD potential role as a substrate for colonization and dispersal vector for NIS in the Madeira Archipelago (NE Atlantic) by examining three MD categories: floating (FMD), seafloor (SMD), and beached (BMD). Opportunistic sampling, conducted in collaboration with local maritime stakeholders, documented MD sightings with photographs and GPS coordinates. A total of 92 MD items were inspected, revealing 108 fouling species across 11 phyla, with 13 % identified as NIS. SMD exhibited the highest proportion of NIS (9.6 %), followed by BMD (4.4 %) and FMD (3.9 %). Notably, the study provides evidence that FMD functions as both a substrate and a dispersal vector for NIS in Madeira waters. Combining biogeographic analyses, oceanographic modelling, and MD identification marks, this study highlighted the North Atlantic Subtropical Gyre's currents as key pathways, transporting MD items from the Wider Caribbean, the North American east coast, and the Iberian Peninsula to Madeira within 2–3 years. These findings emphasize Madeira's dual role as both a recipient and exporter of MD, with implications for NIS introductions and secondary spread. This study underscores the urgent need for standardized monitoring, stakeholder engagement, and proactive MD management strategies to mitigate NIS introductions and protect sensitive marine ecosystems like Macaronesia from the ecological risks of biological invasions.

Microplastics (MPs) were investigated at 19 sandy beaches along the eastern Mediterranean Moroccan coast. Sediment samples (5 mm–63 μ m) were analyzed to identify MPs abundance, size, shape, color and nature. MPs concentration ranged from 40 ± 7.4 to 230 ± 48.6 MPs kg 1 ; fibrous MPs were the most abundant (74.72 %), followed by fragments (20.26 %), films (3.27 %), pellets (1.42 %) and foams (0.33 %). Large MPs (1–5 mm) accounted for 58 %, while small (< 1 mm) for 42 %. The 1–2 mm fraction of sediments presented the greatest amounts (30.67 %) of MPs. Transparent (50 %) and blue (17 %) were most common colors and most of particles were angular and irregularly shaped. Fourier Transform Infrared Spectroscopy (FTIR) analysis showed that PE (Polyethylene), PS (Polystyrene) and PP (Polypropylene) and PVC (Polyvinyl chloride) were the most common polymers. These findings revealed a moderate level of microplastic pollution along the beaches of the eastern Moroccan Mediterranean coast.

This article reviews methods for estimating leaching of PFAS from contaminated materials. Given the variety of methods, selecting those that best simulate assessment objectives is essential. Specific scenarios requiring PFAS leaching assessment, such as leaving materials in place, reuse, and disposal, are discussed. The knowledge gaps presented could be used to improve existing leaching methods for better predictions and understanding of PFAS leachability. | publishedVersion

peer reviewed | Accurate interpretation of mercury (Hg) isotopic data requires the consideration of several biotic factors such as age, diet, geographical range, and tissue metabolic turnover. A priori knowledge of prey-predator isotopic incorporation rates and Hg biomagnification is essential. This study aims to assess Hg stable isotopes incorporation in an Arctic species of Phocidae, the hooded seal Cystophora cristata, kept in human care for 24 months (2012 - 2014) and fed on a constant diet of Norwegian Spring Spawning herring Clupea harengus. We measured THg, MMHg and iHg levels, as well as Hg stable isotope composition with both mass dependent (MDF) and mass independent (MIF) fractionation (e.g. δ202Hg and Δ199,200,201,204Hg) in hooded seal kidney, liver, hair and muscle, in addition to herring muscle. We then calculated Hg MDF and MIF isotopic fractionation between hooded seals and their prey. We found a significant shift in δ202Hg between hooded seal hair (+0.80‰) and kidney (-0.78‰), and herring muscle. In hooded seals tissues δ202Hg correlated positively with MMHg percentage. These findings suggest that tissue-specific Hg speciation is the major driver of changes in Hg isotopic fractionation rates in this Arctic predator. Δ199Hg, Δ200Hg, Δ201Hg and Δ204Hg values did not vary between herring and hooded seal tissues, confirming their utility as tracers of Hg marine and atmospheric sources in top predators. To our knowledge, this represents the first attempt to assess complex Hg isotope dynamics in the internal system of Arctic Phocidae, controlling the effects of age, diet, and distribution. Our results confirm the validity of Hg stable isotopes as tracers of environmental Hg sources even in top predators, but emphasize the importance of animal age and tissue selection for inter-study and inter-species comparisons. | 14. Life below water

Modeling studies illustrate the potential for long-range transport of plastics into the Arctic, although the degree to which this occurs remains relatively undocumented. We utilised a teaching exercise at a UArctic summer school graduate course in Nuuk, Greenland to conduct a preliminary in-depth analysis of beach litter sources in the Nuup Kangerlua fjord. Students and instructors collected and analysed 1800 litter items weighing 200 kg from one location in the fjord and another at its mouth. The results suggest a predominance of local sources to macrolitter, rather than long-range transport from Europe. Fisheries-related items and rope were common. Packaging which could be identified was largely suspected to be products distributed in Greenland, and soft plastics, which rarely disperse far from its source, were also common. The results suggest local measures to reduce mismanaged waste and emissions from fisheries are important for reducing marine litter in West Greenland. | publishedVersion

The main objective with subsea mechanical dispersion (SSMD) is to influence the fate of an oil spill in the marine environment by significantly reducing oil droplet sizes from subsea release of oil. Earlier studies have indicated that the capability of SSMD to reduce oil droplet sizes is comparable to subsea dispersant injection (SSDI). Earlier testing of SSMD has mainly used a low viscus paraffinic oil. Focus for this study was to study SSMD and SSDI effectiveness using five oil types spanning out a wide variation of relevant oil properties. Effectiveness was quantified as the reduction in oil droplet sizes measured by a Silhouette camera. Testing of the two technologies were completed in the same experiment on a simulated subsea release. The results show a variation in effectiveness for both technologies as a function of oil properties. SSMD and SSDI showed comparable effectiveness for all oils tested. | publishedVersion