Dilution of the water chemistry caused by reduced acidification has lately received increased attention, both in Europe and North America. There has also been a declining trend in the supply of sea salts. Several studies have predicted detrimental effects on aquatic life due to dilution. A population of brook trout living in River Hunnedal in southwestern Norway was studied for 14 years (2006–2019).Despite acceptable water chemistry with respect to pH and inorganic Al, limited reproduction was found. With median conductivity, Ca and Na of 7.1– 8.6 μScm−1, and 0.17–0.19 and 0.9–1.0 mgL−1, respectively, the water at the study sites was found to be extremely dilute. We detected a significant positive effect of Na on the densities of brook trout fry, while a less distinct effect of Ca was found. However, due to the correlation between Ca and Na we cannot conclude that Ca is unimportant. For all samplings without catch of fry (n = 13), Na was 0.86 ± 0.15 mgL−1, suggesting a critical limit for Na slightly below 1 mgL−1.We suggest that the reproduction of brook trout was restricted by the highly dilute water and the subsequent scarcity of essential ions. Acidification recovery . Water chemistry . Dilution . Calcium. Sodium. Mountain streams . Brook trout | publishedVersion

peer reviewed | Due to expected changes in climate, it is predicted that disease-carrying mosquitoes will expand their geographical range, resulting in increased use of insect growth regulators (IGRs) to face their proliferation. Among IGRs, pyriproxyfen (PXF) is widely used and has been shown to prevent larvae from developing into adults, rendering them unable to reproduce. However, because of the similarity of crustacean and insect endocrine systems, PXF could also impact aquatic crustaceans. In addition, when spreading in the environment, PXF is found in a mixture with other pollutants such as metallic trace elements, which could alter its effect. Consequently, the present work was devoted to analysing the effects of PXF on the methylfarnesoate (MF) hormonal pathway of the freshwater amphipod Gammarus pulex, as well as its combined binary effects with cadmium (Cd), by measuring MF concentration, as well as the relative transcriptional expression of the farnesoic acid O-methyltransferase (FAMeT) (enzyme limiting the MF production), the methoprene-tolerant receptor (Met), and the broad-complex (BrC) as a transcription factor. Results revealed that single exposures to PXF or Cd have mainly overexpressed FAMeT, Met, and BrC but did not significantly affect MF concentration. Conversely, the mixture exposures seemed to suppress these effects and even achieve antagonistic effects. This work confirmed that PXF single exposure could impact non-target organisms such as amphipods through changes in hormonal pathways of MF. In the same way, it highlighted that Cd could also impair the endocrine system of exposed organisms. However, antagonistic effects have been observed in exposure to mixtures, suggesting different long-term consequences on the growth of amphipods under realistic exposure conditions.

Activated carbon (AC) amendment has been shown to reduce bioavailability of hydrophobic contaminants in the bioactive layer of sediment. Unwanted secondary effects of AC amendment could be particularly undesirable for ecologically important seagrass meadows, but so far, only a few studies have been conducted on effects on submerged plants. The purpose of this study was to investigate effects on growth and cover of submerged macrophytes in situ after AC amendment. Test sites were established within a seagrass meadow in the severely contaminated Norwegian fjord Gunneklevfjorden. Here we show that AC amendment does not influence neither cover nor length of plants. Our study might indicate a positive effect on growth from AC in powdered form. Hence, our findings are in support of AC amendment as a low-impact sediment remediation technique within seagrass meadows. However, we recommend further studies in situ on the effects of AC on submerged vegetation and biota. Factors influencing seasonal and annual variation in plant species composition, growth and cover should be taken into consideration. | An In Situ Experimental Study of Effects on Submerged Vegetation After Activated Carbon Amendment of Legacy Contaminated Sediments | acceptedVersion

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A comprehensive approach to chemical accumulation and biological effects of short-term Cu exposure in juveniles of European seabass (Dicentrarchus labrax) has been achieved. Fish were exposed to 0.01–10 mg L− 1 nominal Cu concentrations for 24–96 h. Metal concentrations in water and gills, liver, muscle and brain tissues were studied along with oxidative stress biomarkers (superoxide dismutase, catalase, glutathione peroxidase, lipid peroxidation). Induction of oxidative damage was observed in all the organs with differential antioxidant responses; gills appearing as the most sensitive from low environmentally water Cu concentrations as 0.01 mg L− 1. Histopathological alterations were also observed in liver and gills, even without a significant Cu accumulation. The results show that the combination of oxidative stress parameters, particularly lipid peroxidation and glutathione peroxidase activities, and histopathological alterations provide a good model fish and reliable early biomarkers for monitoring Cu pollution in seawater and might call for the protection agencies to revise the Cu environmental standards.

peer reviewed | Humpback whales, Megaptera novaeangliae, breeding off la Reunion Island (Indian Ocean) undergo large-scale seasonal migrations between summer feeding grounds near Antarctica and their reproductive winter grounds in the Indian Ocean. The main scope of the current study was to investigate chemical exposure of humpback whales breeding in the Indian Ocean by providing the first published data on this breeding stock concerning persistent organic pollutants (POPs), namely polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), DDT and its metabolites (DDTs), chlordane compounds (CHLs), polybrominated diphenyl ethers (PBDEs), and methoxylated PBDEs (MeO-PBDEs). Analyses of stable isotopes δ13C and δ15N in skin resulted in further insight in their feeding ecology, which was in agreement with a diet focused mainly on low trophic level prey species, such as krill from Antarctica. POPs were measured in all humpback whales in the order of HCB > DDTs > CHLs > HCHs > PCBs > PBDEs > MeO-BDEs. HCB (median: 24 ng.g-1 lw) and DDTs (median: 7.7 ng.g-1 lw) were the predominant compounds in all whale biopsies. Among DDT compounds, p,p’-DDE was the major organohalogenated pollutant, reflecting its long-term accumulation in humpback whales. Significantly lower concentrations of HCB and DDTs were found in females than in males (p<0.001). Other compounds were similar between the two genders (p>0.05). Differences in the HCB and DDTs suggested gender-specific transfer of some compounds to the offspring. POP concentrations were lower than previously reported results for humpback whales sampled near the Antarctic Peninsula, suggesting potential influence of their nutritional status and may indicate different exposures of the whales according to their feeding zones. Further investigations are required to assess exposure of southern humpback whales throughout their feeding zones.

peer reviewed | Aims: To establish a common Key Performance Indicators (KPIs) framework for reporting about the gypsum industry biodiversity at the European level. Methods: In order to integrate different opinions and to reach a consensus framework, an original participatory process approach has been developed among different stakeholder groups: Eurogypsum, European and regional authorities, universities scientists, consulting offices, European and regional associations for the conservation of nature and the extractive industry. The strategy is developed around four main steps: (i) building of a maximum set of indicators to be submitted to stakeholders based on the literature (Focus Group method); (ii) evaluating the consensus about indicators through a policy Delphi survey aiming at the prioritization of indicator classes using the Analytic Hierarchy Process method (AHP) and of individual indicators; (iii) testing acceptability and feasibility through analysis of Environmental Impact Assessments (EIAs) and visits to three European quarries; (iv) Eurogypsum final decision and communication. Results: The resulting framework contains a set of 11 indicators considered the most suitable for all the stakeholders. Conclusions: Our KPIs respond to European legislation and strategies for biodiversity. The framework aims at improving sustainability in quarries and at helping to manage biodiversity as well as to allow the creation of coherent reporting systems. The final goal is to allow for the definition of the actual biodiversity status of gypsum quarries and allow for enhancing it. The framework is adaptable to the local context of each gypsum quarry.

Adverse effects of invasive alien species (IAS), or biological pollution, is an increasing problem in marine coastal waters, which remains high on the environmental management agenda. All maritime countries need to assess the size of this problem and consider effective mechanisms to prevent introductions, and if necessary and where possible to monitor, contain, control or eradicate the introduced impacting organisms. Despite this, and in contrast to more enclosed water bodies, the openness of marine systems indicates that once species are in an area then eradication is usually impossible. Most institutions in countries are aware of the problem and have sufficient governance in place for management. However, there is still a general lack of commitment and concerted action plans are needed to address this problem. This paper provides recommendations resulting from an international workshop based upon a large amount of experience relating to the assessment and control of biopollution.