The Quality Ratio (QR) index was applied in Sepetiba Bay to integrate geochemical and microbiological parameters of the in situ microbial community in order to classify the ecological risk of sediments. Total concentrations (C) of Hg, Cd, As, Pb, Cr, Cu and Zn (indicators of the mixture of contaminants) were determined at 26 stations and at a background area (C₀) to calculate the contamination factor (CF = C/C₀) and the degree of contamination (ΣCF). Enzymatic biomarkers of energy production into cell (dehydrogenase - DHA) and hydrolase of organic matter outside the cell (esterases - EST) were determined. The QR, a function of the microbial term (DHA/EST) and the geochemical term (TOC × ΣCF/fine-grained content), was able to segregate stations into the internal sector (east of the bay with the largest continental contributions) and the external sector (west of the bay), proving its accessibility (low-cost and fast) and efficiency for assessing ecological risk.

Fatty acids (FAs) composition, 24 persistent organic pollutants (POPs), and 16 trace elements were examined in small pelagic fish (sardine, anchovy, round sardinella, chub and horse mackerels) caught by a fishing fleet for more than three years in the eastern Mediterranean Sea. Five Unmix source profiles associated with both sources, such as overlapping diet, including low-niche marine organisms and inputs from the surrounding environmental compartments were resolved. Inorganic compounds were notably more abundant in fish tissue than organochlorine xenobiotics. Comparison with the values of toxicological parameters revealed that the examined fish species are safe for human consumption, while the content of FAs emphasized the studied species as a valuable source of nutrients. A significant linear correlation was not observed between the 18 FAs and lipophilic organochlorines. Based on the obtained database, future assessments of the quality of edible fish species and the aquatic environment of the eastern Mediterranean Sea, which is known as an important fishing ground, could be significantly improved.

Systematic Conservation Planning (SCP) offers concepts and toolboxes to make spatial decisions on where to focus conservation actions while minimizing a variety of costs to stakeholders. Thirty-four studies of Pacific Ocean Tropical Islands were scrutinized to categorize past and current types of applications. It appeared that scenarios were often built on a biodiversity representation objective, opportunity costs for fishers was the most frequent cost factor, and an evolution from simple to sophisticated scenarios followed the need to maximize resilience and connectivity while mitigating climate change impacts. However, proxies and models were often not validated, pointing to data quality issues. Customary management by local communities motivated applications specific to the Pacific region, but several island features remained ignored, including invertebrate fishing, ciguatera poisoning and mariculture. Fourteen recommendations are provided to enhance scenarios' robustness, island specificities integration, complex modelling accuracy, and better use of SCP for island management.

Studies examining nanoparticles (NPs) and hazardous elements (HEs) contained in suspended sediments (SSs) are vital for watershed administration and ecological impact evaluation. The biochemical consequence of titanium-nanoparticles (Ti-NPs) from SSs in Colombia's Magdalena River was examined utilizing an innovative approach involving nanogeochemistry in this study. In general, the toxicity and the human health risk assessment associated with the presence of some Ti-NPs + HEs in SSs from riverine systems need to be determined with a robust analytical procedure. The mode of occurrence of Ti-NPs, total Ti and other elements contained within SSs of the Magdalena River were evaluated through advanced electron microscopy (field emission scanning electron microscope-FE-SEM and high resolution transmission electron microscope-HR-TEM) coupled with an energy dispersive X-ray microanalysis system (EDS); X-Ray Diffractions (XRD); and inductively coupled plasma-mass spectrometry (ICP-MS). This work showed that enormous quantities of Ti-NPs were present in the river studied and that they displayed diverse geochemical properties and posed various possible ecological dangers. Ti-NP contamination indices must be established for measuring the environmental magnitudes of NP contamination and determining contamination rank among rivers. Finally, SS contamination guidelines must be recommended on an international level. This study contributes to the scientific understanding of the relationship of HE and Ti-NP dynamics from SSs in riverine systems around the world.

A mesocosm experiment was conducted on the Qingdao coast to study the effects of nutrient enrichment on the physiological responses of Ulva prolifera and the changes in the entire culture system during decomposition of algal blooms. The decomposition trend of U. prolifera off the Qingdao coast was slightly retarded by nutrient enrichment, and could not be reversed to positive growth. The decomposition of U. prolifera was divided into two stages: the early-stage (0–9 d) and the late-stage (9–19 d). High nutrient levels enhanced the amounts of carbon and nitrogen fixed by U. prolifera and accelerated the subsequent degradation of organic matter. The concentration and composition of amino acids in solution also changed, reducing the bioavailability of dissolved organic matter in seawater. This study evaluated the actual decomposition process of green tides, which will help to assess the impact of green tides on coastal ecosystems and the circulation of biogenic elements.

PURPOSE OF REVIEW: Untreated wastewater discharge can significantly and negatively impact the state of the environment. Rapid industrialization and economic development have directly contributed to land and water pollution resulting from the application of many chemicals such as organic dyes, pharmaceuticals, and industrial reagents. The removal of these chemicals before effluent discharge is crucial for environmental protection. This review aims to explore the importance of functionalized materials in the preparation of biocatalytic systems and consider their application in eliminating water pollutants. RECENT FINDINGS: Wastewater treatment methods can be classified into three groups: (i) chemical (e.g., chemical oxidation and ozonation), (ii) physical (e.g., membrane separation and ion exchange), and (iii) biological processes. Biological treatment is the most widely used method due to its cost-effectiveness and eco-friendliness. In particular, the use of immobilized enzymes has recently become more attractive as a result of scientific progress in advanced material synthesis. The selection of an appropriate support plays an important role in the preparation of such biologically active systems. Recent studies have demonstrated the use of various materials for enzyme immobilization in the purification of water. This review identifies and discusses different biocatalytic systems used in the enzymatic degradation of various water pollutants. Materials functionalized by specific groups can serve as good support matrices for enzyme immobilization, providing chemical and thermal stability to support catalytic reactions. Enzymatic biocatalysis converts the pollutants into simpler products, which are usually less toxic than their parents. Due to immobilization, the enzyme can be used over multiple cycles to reduce the cost of wastewater treatment. Future studies in this field should focus on developing new platforms for enzyme immobilization in order to improve degradation efficiency.

In 2010, Indonesia estimated as the second-largest country in the world that donates plastic to the sea. This study aims to investigate the spatial and temporal distribution of microplastics in tropical estuaries. The sampling was carried out in Benoa Bay with four repetitions representing the wet and dry seasons. Spatially it was found that the highest microplastic abundance around the Suwung landfill, while the lowest at Badung River Estuary, middle, and an inlet of the Benoa Bay. The highest percentage to the lowest microplastic based on the size was 500–1000 μm (37.9%), >1000 μm (35.7%), 300–500 μm (22.1%), and <300 μm (4.3%), while based on the shape were fragments (73.19%), foam (17.02%), fiber (6.38%), and granule (3.40%). No significant differences were found between the wet and dry seasons based on the abundance, but significantly varied based on size and shape. Polymers of microplastics were dominated by polystyrene, polypropylene, and polyethylene.

Ocean acidification (OA) could become a serious threat for the Antarctic marine ecosystem over coming years, as the solubility of atmospheric CO₂ and CaCO₃ minerals increases at lower temperatures. We evaluated the effect of OA on the stress response of the limpet Nacella concinna by measuring gene expression levels. The experiment was performed with the two ecotypes (Littoral and Sublittoral) of the species during 54 days (IPCC, 2019 scenario RCP8.5; control, ~375 ppm; low-pH treatment, ~923 ppm). Exposure to low-pH treatment during 15 days triggered the down-regulation of two heat-shock protein genes (HSP70A, HSP70B) only in sublittoral individuals. Little variation in the relative expression values of all genes in both ecotypes was observed probably, due to a historical exposure to the substantial daily natural pH fluctuations recorded in the study area during the experiment. This study provides relevant baseline data for future OA experiments on coastal species in Antarctica.

PURPOSE OF REVIEW: Microplastic (MP) pollution is a global concern due to its prevalence and persistence in the environment. Aquatic sediments, particularly marine sediments, are considered as the potential final sink of this pollution. This review summarizes (1) the fate and transport of microplastics (MPs) in waters and aquatic sediments and (2) the ecological impact of MPs, including the interactions between MPs and microbiome, and the effects of MPs on living organisms in aquatic sediments. RECENT FINDINGS: Characteristics of MPs, water movement, and weathering conditions determine the fate and transport of MPs. These factors influence MPs’ travel and inclination to settle. The interactions of MPs and microbiome can alter bacterial communities, cause MPs’ biodegradation, and facilitate biofouling that subsequently changes the fate and transport of MPs. MP presence poses exposure risks to benthic organisms through direct ingestion or trophic transfer, negatively affecting not only individual organisms but also the fauna. The destiny of MPs is affected by many factors, from MPs’ characteristics to water movement and weathering. Thus, future research is warranted to develop comprehensive modeling tools that include all the key factors to better understand and predict the fate and transport of MPs in aquatic environments and sediments. The potential impact from the exposure to MPs on the ecosystem of aquatic sediments is relatively less studied. More research is needed in this area, particularly from a systematic level, to understand how different biotic and abiotic factors will interact together and what the consequential impact of these interactions on ecological and human health are.

In this paper a novel methodology to assess the risk of marine litter (ML) pollution in the Mediterranean Sea is implemented. In this approach, the hazard component is estimated using a state-of-the-art 3D modeling system, which allows the simulation of floating and sinking ML particles; the exposure component is defined from biodiversity estimates; and the vulnerability is related to ML ingestion rates of each species. The results show that the hot-spots for the ML risk concentrate in the coastal regions, and are mainly conditioned by the biodiversity in the region. A dedicated analysis on the marine protected areas shows that the risk therein is controlled by the proximity to ML sources and that their present-day protection levels are not effective in the case of ML pollution. Only a reduction of ML at the sources could reduce the impact of ML pollution in protected areas.