Eutrophication is a major threat to aquatic ecosystems, because excessive nutrient enrichment may result in the loss of ecosystem services. Fjord systems are specifically under pressure due to nutrient input from land (agriculture) and sea (aquaculture). In this bioassay study, we have analyzed the effect of different nutrient sources, as well as their combination, on growth, nutrient composition and recruitment of habitat-forming and ephemeral macrophytes. We found that agricultural fertilizer increased growth for all algae (except Fucus), while the fish farm effluents mainly increased growth of Ulva. The C:N ratio was hardly affected by the fish farm, but decreased significantly in all algae when agriculture fertilizer was added. Most interestingly, however, distance to the fish farm modulated the algal response to the fertilizer. Our results demonstrate the importance of studying effects of multiple stressors in aquatic ecosystems to sustainably manage the consequences of anthropogenic impacts. | publishedVersion

Small-scale experiments performed at SINTEF, Norway in 2011–12 led to the development of a modified Weber scaling algorithm. The algorithm predicts initial oil droplet sizes (d50) from a subsea oil and gas blowout. It was quickly implemented in a high number of operational oil spill models used to predict fate and effect of subsea oil releases both in academia and in the oil industry. This paper presents experimental data from large-scale experiments generating oil droplet data in a more realistic multi-millimeter size range for a subsea blow-out. This new data shows a very high correlation with predictions from the modified Weber scaling algorithm both for untreated oil and oil treated by dispersant injection. This finding is opposed to earlier studies predicting significantly smaller droplets, using a similar approach for estimating droplet sizes, but with calibration coefficients that we mean are not representative of the turbulence present in such releases. | publishedVersion

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Despite the large research effort on reporting quantities of coastal litter, the dynamics of this litter is not yet sufficiently understood. Litter inputs in five cobble beaches located in the Mediterranean (Spain) were studied over three months during winter by biweekly litter tagging. Plastic represented the dominant material that reached the beaches (77%). In remote and narrow beaches, storms constituted the main driver in litter dynamics, favouring the accumulation of floating items such as plastic bottles and wood fragments as well as the largest but contrasting effects, increasing litter inputs and outputs from the beach, respectively. In rural beaches, beach users, mainly fisher people, but also tourists, contributed to a notable input of litter to the beach. Burial and exhumation of litter were reported as common occurring processes. Better management actions are required to improve beach environmental quality. | This research is a contribution to the Andalusia PAI Research Group "RNM-328" and to the Ibero-American Beach Management and Certification Network -PROPLAYAS. This work was supported by the Biodiversity Foundation of the Ministry for the Ecological Transition and Demographic Challenge from Spain [FBIOMARINA19-01]. Special thanks go to David Saez, Natalia Sanchez, Laura Valero and Alba Amat for their help during the sampling periods and thanks to "Puertos del Estado" for oceanographic data. Thanks are also given to the municipalities involved in this research for answering to enquires about beach cleaning modalities. Finally, special thanks to two anonymous reviewers for their useful comments and suggestions, which have been very helpful in improving the manuscript.

Biomonitoring studies are helpful tools and can increase our knowledge on time trends in human blood concentrations of PFASs: how they relate to emission trends and the potential prenatal exposure for future generations. In this study, serum was sampled in cross-sections of men and women who were 30 years old in each of the years 1986, 1994, 2001, and 2007 in Northern Norway and analyzed for 23 PFASs. Differences in serum concentrations across sampling years were investigated graphically and with significance testing and compared with those observed in our previous longitudinal study using repeated individual measurements in older men in the same years. The results demonstrate overall increasing blood burdens of PFASs in men and women in reproductively active ages during 1986–2001 and decreases until 2007. However, longer chained PFASs were still increasing in 2007 indicating divergent time trends between the different PFASs, underlining the importance of continued biomonitoring. Comparisons between 30-year-old men and older men within the same population demonstrated variation in time trends in the exact same years, underlining that biomonitoring studies must regard historic exposures and birth cohort effects. | publishedVersion

Considerable amounts of previously deposited persistent organic pollutants (POPs) are stored in the Arctic cryosphere. Transport of freshwater and terrestrial material to the Arctic Ocean is increasing due to ongoing climate change and the impact this has on POPs in marine receiving systems is unknown This study has investigated how secondary sources of POPs from land influence the occurrence and fate of POPs in an Arctic coastal marine system. Passive sampling of water and sampling of riverine suspended particulate matter (SPM) and marine sediments for analysis of polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) was carried out in rivers and their receiving fjords in Isfjorden system in Svalbard. Riverine SPM had low contaminant concentrations (<level of detection-28 pg/g dw ΣPCB14, 16–100 pg/g dw HCB) compared to outer marine sediments 630-880 pg/g dw ΣPCB14, 530–770 pg/g dw HCB). There was a strong spatial gradient in sediment PCB and HCB concentrations with lowest concentrations in river estuaries and in front of marine-terminating glaciers and increasing concentrations toward the outer fjord. This suggests that rather than leading to increased concentrations, inputs of SPM from land lead to a dilution of contaminant concentrations in nearshore sediments. Preliminary estimates of SPM:water activity ratios suggest that terrestrial particles (with low contaminant concentrations) may have the potential to act as sorbents of dissolved contaminants in the coastal water column, with implications for bioavailability of POPs to the marine food web. There is concern that ongoing increases in fluxes of freshwater, sediments and associated terrestrial material (including contaminants) from land to the Arctic Ocean will lead to increased mobilization and transport of POPs to coastal ecosystems. However, the results of this study indicate that on Svalbard, inputs from land may in fact have the opposite effect, leading to reduced concentrations in coastal sediments and waters. | publishedVersion

One of the ambitions of the UN Decade of Ocean Science is stakeholder interaction to co-produce new ideas and solutions for policy action plans to ensure that environmental challenges are mitigated in a timely manner. Regulations around the release of microfibres are largely lacking, and we are at an excellent point of departure to test integrative methods of such co-production. We co-designed conceptual maps and Bayesian Belief Networks with probabilistic future scenarios within both inter- and intra-sectoral workshops with industry and scientific stakeholders to gain comparable results of policy action scenarios for curbing the challenge of microfibre pollution within this context. We found that when scientists worked on this alone, their focus was different than when working together with industry directly. Scientists focused on methods for avoiding release into the environment from a technical vantage point, whereas industry emphasized regulatory requirements needed to avoid ambiguity within the sector. | publishedVersion

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International audience | Metabolic disorders induced by endocrine disruptors (ED) may contribute to amphibian population declines but no transgenerational studies have evaluated this hypothesis. Here we show that Xenopus tropicalis, exposed from the tadpole stage, to the ED benzo[a]pyrene (BaP, 50 ng.L−1) produced F2 progeny with delayed metamorphosis and sexual maturity. At the adult stage, F2–BaP females displayed fatty liver with inflammation, tissue disorganization and metabolomic and transcriptomic signatures typical of nonalcoholic steato-hepatitis (NASH). This phenotype, similar to that observed in F0 and F1 females, was accompanied by a pancreatic insulin secretory defect. Metabolic disrupted F2–BaP females laid eggs with metabolite contents significantly different from the control and these eggs did not produce viable progeny. This study demonstrated that an ED can induce transgenerational disruption of metabolism and population collapse in amphibians under laboratory conditions. These results show that ED benzo[a]pyrene can impact metabolism over multiple generations and support epidemiological studies implicating environmental EDs in metabolic diseases in humans.