Polycyclic Aromatic Hydrocarbons (PAHs) are among the main persistent organic pollutants in the Arcticwhich enter the polar region from lower latitudes by air transport and ocean currents and accumulate in marine sediments. This work represents the first study in 25 years of the least studied and hard-to-reach areas of Siberian arctic seas. Sixteen priority PAHs as well as 1- and 2-methylnaphthalenes were analyzed by gas chromatography – tandem mass spectrometry in the twenty-four sediment samples taken from Kara, Laptev and East Siberian Seas in October 2020. The obtained sum concentrations ranged from 31 to 223 ng/ g with the greatest contribution of phenanthrene, benzo[b]fluoranthene, benzo[k]fluoranthene, as well as naphthalene and its methyl derivatives while the greatest PAH levels were observed in Laptev Sea. No correlations between sum PAH concentration, total organic carbon and black carbon contents were found. The toxic equivalent in benzo[a]pyrene units was from 2.2–18.2 ng/ g that shows the general safe environmental situation in the region. The overall PAH level is comparable with the data obtained in 1990s which indicates a long-term persistence of pollution despite an overall decline in global PAH emissions. The main sources of PAHs involve mainly coal/biomass and liquid fuel combustion with weaker contribution of petroleum sources.

Bivalve molluscs represent the most recognized bioindicators of freshwater pollution. However, their ability to indicate specific xenobiotics in complex exposures is unclear. In this study, we aimed to track the particular effects of the pesticide Roundup (Rnd) and the antipsychotic drug chlorpromazine (Cpz) on the mussel Unio tumidus at the simpler environmentally relevant models. We treated the mussels by Rnd (17 μg L−1), Cpz (18 μg L−1), the mixture of Rnd and Cpz at 18 °C (RndCpz), and Rnd at 25 °C (RndT) and examined their digestive glands after 14 days of exposure. We analyzed total antioxidant capacity, glutathione (GSH&GSSG) and protein carbonyls levels, total and Zn-related concentrations of metallothioneins (MT and Zn-MT, respectively), the activities of CYP450-related EROD, glutathione S-transferase, cholinesterase, caspase-3, citrate synthase (CS), lysosomal membrane integrity (NRR), and Zn level in the tissue. Shared responses were indicated as the increase of the antioxidant, Zn-MT, and EROD levels, whereas the changes of Zn concentration, NRR, and caspase-3 activity were most diverse compared to control. According to discriminant analysis, complex exposures abolished the individual response traits and intensified the harmful effects that caused a decrease in the Zn level in the RndCpz- and RndT-groups and the loss of lysosomal integrity in the RndT-group. We concluded that multi-marker expertise with the application of integrated indices had benefits when evaluating the effects of complex exposures. Graphical abstract: [Figure not available: see fulltext.].

Sticklebacks (Gasterosteiformes) are increasingly used in ecological and evolutionary research and have become well established as role model species for biologists. However, ecotoxicology studies concerning behavioural effects in sticklebacks regarding stress responses, mainly induced by chemical mixtures, have hardly been addressed. For this purpose, we investigated the swimming behaviour (including mortality rate based on 96-h LC50 values) of two ecologically similar three-spined (Gasterosteus aculeatus) and nine-spined sticklebacks (Pungitius pungitius) to short-term (up to 24 h) metal mixture (MIX) exposure. We evaluated the relevance and efficacy of behavioural responses of test species in the early toxicity assessment of chemical mixtures. Fish exposed to six (Zn, Pb, Cd, Cu, Ni, and Cr) metals in the mixture were either singled out by the Water Framework Directive as priority or as relevant substances in surface water, which was prepared according to the environmental quality standards (EQSs) of these metals set for inland waters in the European Union (EU) (Directive 2013/39/EU). The performed behavioural analysis showed the main effect on the interaction between time, species, and treatment variables. Although both species exposed to MIX revealed a decreasing tendency in swimming activity, these species' responsiveness to MIX was somewhat different. Substantial changes in the activity of G. aculeatus were established after a 3-h exposure to MIX solutions, which was 1.43-fold lower, while in the case of P. pungitius, 1.96-fold higher than established 96-h LC50 values for each species. This study demonstrated species-specific differences in response sensitivity to metal-based water pollution, indicating behavioural insensitivity of P. pungitius as model species for aquatic biomonitoring and environmental risk assessments.v.

Aquaculture practices at sea are far from impact neutral and remain an important source of marine plastic pollution. With projected rapid continual growth in the sector, if left unmanaged, aquaculture pollution can have detrimental environmental and social implications. Using the DPSIR framework, the paper examines current practices and pathways of plastic pollution from marine aquaculture in the NE-Atlantic, drawing on findings from literature, stakeholder consultations and beach litter assessments. Pathways for aquaculture-related litter identified include rough weather, farmer behavior, inadequate access to recycling facilities, low price of consumable plastics and high cost of recycling. Beach litter analyses conducted as part of the study exposed serious issues of under quantification, resulting from difficulties in source identification and a lack of detailed categorization in official monitoring systems. The paper makes recommendations to improve litter quantification and waste management, including the use of local knowledge and experts to identify sources of marine litter.

This study investigated the concentration fluctuation of organotin compounds in the Turbidity Maximum Zone (TMZ) of the Yangtze Estuary within a tidal cycle. Organotin concentrations varied greatly during the tidal cycle with dissolved organotins ranged from 39 to 682 ng Sn·L⁻¹ and 40–1588 ng Sn·L⁻¹, and particulate organotins ranged from 59 to 467 ng Sn·g⁻¹ dw and 21–429 ng Sn·g⁻¹ dw in TMZ water close to Hengsha Island and Jiuduansha Island, respectively. Meanwhile, the maximum levels of organotins appeared at each period of tidal transition, suggesting the tidal-driven pulsed exposure of organotins was prevalent in the estuaries. Besides, the organic carbon-normalized partition coefficients (Kₒc) of tri-organotins between suspended particulate matter (SPM) and aqueous phase were correlated with the phase distribution of natural organic matter (NOM). The dissolved tri-organotins were also associated with the properties of dissolved organic carbon (DOC) including aromaticity, hydrophobicity, and chromophoricity. Hence, pulsed exposure on organotins in the TMZ are highly dictated by the dynamic environmental conditions (i.e., SPM and NOM) with the tidal currents, which could further provide information to assess organotin ecological risks accurately in estuaries.

Phytoplankton assemblage and chlorophyll a along the salinity gradient and oxygen zonation were studied in Ulhas Estuary. Oxic condition exist in euhaline region of the estuary that receives oxygenated coastal waters, while, poly-meso-oligohaline region is hypoxic due to the accumulation of voluminous amount of pollutants from industrial effluents, domestic/sewage and agricultural discharges. Additionally, anthropogenically generated nutrients enhanced phytoplankton biomass (chlorophyll a) and their senescence also led to hypoxia. The dominance of diatoms (>70%) was observed in the euhaline-oxic region, while a tremendous decrease in their contribution (18%) was observed in the oligohaline region. Meso to oligohaline region of the estuary is governed by cyanophytes and chlorophytes due to their affinity towards low salinity and high dissolved inorganic nutrients. Carlson's Trophic State Index (TSI) further substantiated the estuary as eutrophic. Additionally, the study could identify the adaptation of cyanophytes and chlorophytes in oxygen deficient water.

Coral diseases contribute to the rapid degradation of coral reefs on a global scale. Although widespread in tropical and subtropical reefs, disease outbreaks have not been described in warm temperate areas. Here, we report the outbreak of a new coral disease in a warm temperate marginal coral community in Japan. Outbreaks of the disease have been observed during the summer and autumn months since 2014. It affects the coral species Porites heronensis and was tentatively named “White Mat Syndrome” (WMS) as it consists of a white microbial mat dominated by Thiothrix sp., a sulfide oxidizing bacteria. Outbreaks followed high seasonal temperatures and were associated with the macroalga Gelidium elegans, which acts as a pathogen reservoir. With ocean warming and the anticipated increase in novel coral-algae interactions as some coral species shift poleward, WMS and emerging diseases could hinder the role of temperate areas as a future coral refuge.

PURPOSE OF REVIEW: The development of various type of wastewater treatment technologies provides significant supports for environmental protection. Biofiltration, an attached growth system, shows remarkable performance in treating different types of wastewater worldwide. Differing from the existing comprehensive reviews published thus far, this review article focuses on the current prospects and future research trends of biofiltration in wastewater treatment through bibliometric analysis. The objective of the study is to analyze the applications of biofiltration in wastewater treatment in terms of the annual publications trend, most productive journals, leading authors, countries and affiliations, keywords, and the type of wastewater treated. RECENT FINDINGS: The findings clearly showed that there is an increasing trend in the annual publications of biofiltration in wastewater treatment in the period from 1969 to 2020. The analysis revealed that Water Research, Mr. Rocher, V (Rocher, Vincent), and China is the leading journal, author, and country in terms of total publications. Through the co-occurrence analysis of the author keywords, keyword such as “biofilter” was identified as the most frequently used author keywords with 213 occurrences and 178 links to other author keywords. Besides that, the findings also show that there are still lacking of studies related on the treatment of “refinery wastewater,” “pharmaceutical wastewater,” “coal gasification wastewater,” and “brewery wastewater” by using biofiltration system. Overall, the findings of this bibliometric analysis can be helpful information for industry practitioners and researchers that lead on water pollution control technologies.

Mangroves are often exposed to heavy metals that accumulate in the food chain, generate toxicity to mangrove plants and affect microbial diversity. This study determined the abundance of genes associated with resistance and tolerance to heavy metals in the rhizosphere microbiome of Avicennia germinans from a semi-arid mangrove of La Guajira-Colombia by metagenomics and genomics approach. Twenty-eight genes associated with tolerance and 49 genes related to resistance to heavy metals were detected. Genes associated with tolerance and resistance to Cu, especially cusA and copA, were the most abundant. The highest number of genes for tolerance and resistance were for Zn and Co, respectively. The isolate Vibrio fluvialis showed the ability to tolerate Cu, Ni, Zn, and Cd. This work used a complementary approach of metagenomics and genomics to characterize the potential of mangrove microorganisms to tolerate and resist heavy metals and the influence of salinity on their abundance.