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Driftskontroll av kalkdoseringsanlegg i Arendalsvassdraget År 2022
Get PDFProsjektleder: Rolf HøgbergeDriftskontroll av kalkdoseringsanlegg i Arendalsvassdraget gjennomføres for å avdekke effektiviteten til anleggene. Denne statusrapporten gir en dokumentasjon på driften i rapporteringsperioden (2022) for Bøylefoss- og Gauperå-anleggene, og inneholder samtidig en fortegnelse over hendelser og avvik som kan danne grunnlag for forbedringstiltak knyttet til driftsrutiner, installasjoner eller kalkingsstrategi. Redusert kalkbehov medførte at Bøylefoss-anlegget ikke doserte i 4 måneder. Totalt kalkforbruk gjennom året var bare 60 % av forbruket i 2021, som igjen var 66 % av forbruket i 2020. For bedre informasjon omkring pH og temperaturutvikling bør det etableres logging av vanntemperaturene både oppstrøms og nedstrøms Bøylefoss-anlegget. Doseringseffektiveten vurderes som god. Driftslogg fra Gauperå-anlegget mangler i tiden før 10. mars 2022. Både pH oppstrøms og nedstrøms anlegget viste periodevis feil, og vannføringsmålingene bør kalibreres bedre mot vannstanden. Doseringen kom ofte for sent i gang ved behov, og det foreslås tiltak for bedring av responstiden. Ved flere tilfeller ble det overdosert kalk i forbindelse med flom. Det oppsto en del tilfeller med for lav pH i forhold til målet. Doseringseffektiveten vurderes som mindre god. MikaCom-systemet har gjennomgått en oppgradering, men mangler fortsatt god tidsstempling av måledata, og det foreslås derfor tiltak for å forbedre dette.Froland KommunepublishedVersio
Tålegrenser for forsuring og overskridelser for Høyangervassdraget i Vestland fylke
Get PDFProsjektleder: Cathrine Brecke GundersenDet har blitt beregnet tålegrenser for forsuring og overskridelse av disse for Høyangervassdraget og separat for delnedbørfeltene Håland, Gautingsdal og Eiriksdal. Overskridelser er beregnet for dagens (årene 2017-2021) og framtidige (år 2030 og 2050) avsetninger av svovel og nitrogen. Både SSWC- og FAB-modellene ble benyttet. Resultatene viser ingen overskridelse i nedbørfeltene for alle tidsperiodene. På grunn av forsinkelser i systemene kan det være forsuring selv om tålegrensene ikke er overskredet. Men så lenge det ikke er overskridelse, vil forsuringen gradvis avta, og de sure episodene vil bli mindre hyppigere og alvorlige.Statsforvalteren i VestlandpublishedVersio
Long-term rise in riverine dissolved organic carbon concentration is predicted by electrolyte solubility theory
Get PDFThe riverine dissolved organic carbon (DOC) flux is of similar magnitude to the terrestrial sink for atmospheric CO2, but the factors controlling it remain poorly determined and are largely absent from Earth system models (ESMs). Here, we show, for a range of European headwater catchments, that electrolyte solubility theory explains how declining precipitation ionic strength (IS) has increased the dissolution of thermally moderated pools of soluble soil organic matter (OM), while hydrological conditions govern the proportion of this OM entering the aquatic system. Solubility will continue to rise exponentially with declining IS until pollutant ion deposition fully flattens out under clean air policies. Future DOC export will increasingly depend on rates of warming and any directional changes to the intensity and seasonality of precipitation and marine ion deposition. Our findings provide a firm foundation for incorporating the processes dominating change in this component of the global carbon cycle in ESMs.publishedVersio
Enhanced denitrification of biodegradable polymers using Bacillus pumilus in aerobic denitrification bioreactors: Performance and mechanism
No full textNitrate accumulation is an important issue that affects animal health and causes eutrophication. This study combined biodegradable polymers with degrading bacteria to lead to high denitrification efficiency. The results showed polycaprolactone had the highest degradation and carbon release rate (0.214 mg/g∙d) and nitrogen removal was greatest when the Bacillus pumilus and Halomonas venusta ratio was 1:2. When the hydraulic retention time was extended to 12 h, the nitrate removal rate for H. venusta with B. pumilus and polycaprolactone increased by 48 %. Furthermore, the group with B. pumilus contained more Proteobacteria (77.34 %) and denitrifying functional enzymes than the group without B. pumilus. These findings indicated B.pumilus can enhance the degradation of biodegradable polymers especially polycaprolactone to improve the denitrification of the aerobic denitrification bacteria H.venusta when treating maricultural wastewater.acceptedVersio
Levelling-up rhodolith-bed science to address global-scale conservation challenges
Get PDFGlobal marine conservation remains fractured by an imbalance in research efforts and policy actions, limiting progression towards sustainability. Rhodolith beds represent a prime example, as they have ecological importance on a global scale, provide a wealth of ecosystem functions and services, including biodiversity provision and potential climate change mitigation, but remain disproportionately understudied, compared to other coastal ecosystems (tropical coral reefs, kelp forests, mangroves, seagrasses). Although rhodolith beds have gained some recognition, as important and sensitive habitats at national/regional levels during the last decade, there is still a notable lack of information and, consequently, specific conservation efforts. We argue that the lack of information about these habitats, and the significant ecosystem services they provide, is hindering the development of effective conservation measures and limiting wider marine conservation success. This is becoming a pressing issue, considering the multiple severe pressures and threats these habitats are exposed to (e.g., pollution, fishing activities, climate change), which may lead to an erosion of their ecological function and ecosystem services. By synthesizing the current knowledge, we provide arguments to highlight the importance and urgency of levelling-up research efforts focused on rhodolith beds, combating rhodolith bed degradation and avoiding the loss of associated biodiversity, thus ensuring the sustainability of future conservation programs.acceptedVersio
Understanding temporal variability across trophic levels and spatial scales in freshwater ecosystems
Get PDFA tenet of ecology is that temporal variability in ecological structure and processes tends to decrease with increasing spatial scales (from locales to regions) and levels of biological organization (from populations to communities). However, patterns in temporal variability across trophic levels and the mechanisms that produce them remain poorly understood. Here we analyzed the abundance time series of spatially structured communities (i.e., metacommunities) spanning basal resources to top predators from 355 freshwater sites across three continents. Specifically, we used a hierarchical partitioning method to disentangle the propagation of temporal variability in abundance across spatial scales and trophic levels. We then used structural equation modeling to determine if the strength and direction of relationships between temporal variability, synchrony, biodiversity, and environmental and spatial settings depended on trophic level and spatial scale. We found that temporal variability in abundance decreased from producers to tertiary consumers but did so mainly at the local scale. Species population synchrony within sites increased with trophic level, whereas synchrony among communities decreased. At the local scale, temporal variability in precipitation and species diversity were associated with population variability (linear partial coefficient, β = 0.23) and population synchrony (β = −0.39) similarly across trophic levels, respectively. At the regional scale, community synchrony was not related to climatic or spatial predictors, but the strength of relationships between metacommunity variability and community synchrony decreased systematically from top predators (β = 0.73) to secondary consumers (β = 0.54), to primary consumers (β = 0.30) to producers (β = 0). Our results suggest that mobile predators may often stabilize metacommunities by buffering variability that originates at the base of food webs. This finding illustrates that the trophic structure of metacommunities, which integrates variation in organismal body size and its correlates, should be considered when investigating ecological stability in natural systems. More broadly, our work advances the notion that temporal stability is an emergent property of ecosystems that may be threatened in complex ways by biodiversity loss and habitat fragmentation.publishedVersio
Var forurensning fra utfyllingsarbeid ved Northern Lights landanlegg årsaken til at mye laks døde etter avlusning i oppdrettsanlegget Ljøsøy N?
Get PDFProsjektleder: Jonny BeyerNIVA har på oppdrag fra Northern Lights’ landanlegg (NLL) utført en faglig vurdering av hendelsen der unormalt mye oppdrettslaks døde hos Blom Fiskeoppdrett (BF) etter en ferskvannsbehandling i brønnbåt i juni 2021. Bakgrunnen for oppdraget var en påstand fra BF om årsakssammenheng mellom et utfyllingstiltak av steinmasser i Ljøsøysundet (ved NLL) og den aktuelle fiskedøden, fokusert særlig på skadelig aluminium. Basert på gjennomgang av saken og med støtte i relevant faglig litteratur finner NIVA flere svakheter ved påstanden om årsakssammenheng for fiskedøden. For det første viste in‐situ målinger av turbiditet at nivåene av partikler verken var over den tillatte tiltaksgrensen eller nær de nivåene som kan forårsake skade på fisk. Målingene av gjellealuminium var heller ikke så høye at de kan forklare akutt dødelighet, og slike effekter av aluminium er heller ikke tidligere vist på fisk eksponert for aluminium i fullt sjøvann. Tidligere studier både fra Sør‐ og Vestlandet har vist at risiko for aluminiumspåslag og fysiologisk skade på laks i sjøvann er minimal når saliniteten overstiger 10‐15 promille. På grunn av høy pH og salinitet i sjøvann er konsentrasjonene til giftige, labile aluminiumsforbindelser meget lave. Det er derfor minimaltmed giftig aluminium i sjøvann. De forelagte histologiske dataene viste videre at overlevende fisk fra lokaliteten hadde gjeller med minimale patologiske forandringer, som ikke viste noen tegn verken til aluminiums‐ eller partikkelrelatert skade. Totalt sett vurderer NIVA det som lite sannsynlig at gjelleskadelig aluminium eller ska delige partikler fra NLLs utfyllingstiltak var årsaken tilden høye fiskedødeligheten hos BF i juni 2021.Northern Lights landanlegg og Equinor ASApublishedVersio
Big Question to Developing Solutions: A Decade of Progress in the Development of Aquatic New Approach Methodologies from 2012 to 2022
Get PDFIn 2012, 20 key questions related to hazard and exposure assessment and environmental and health risks of pharmaceuticals and personal care products in the natural environment were identified. A decade later, this article examines the current level of knowledge around one of the lowest-ranking questions at that time, number 19: “Can nonanimal testing methods be developed that will provide equivalent or better hazard data compared with current in vivo methods?” The inclusion of alternative methods that replace, reduce, or refine animal testing within the regulatory context of risk and hazard assessment of chemicals generally faces many hurdles, although this varies both by organism (human-centric vs. other), sector, and geographical region or country. Focusing on the past 10 years, only works that might reasonably be considered to contribute to advancements in the field of aquatic environmental risk assessment are highlighted. Particular attention is paid to methods of contemporary interest and importance, representing progress in (1) the development of methods which provide equivalent or better data compared with current in vivo methods such as bioaccumulation, (2) weight of evidence, or (3) -omic-based applications. Evolution and convergence of these risk assessment areas offer the basis for fundamental frameshifts in how data are collated and used for the protection of taxa across the breadth of the aquatic environment. Looking to the future, we are at a tipping point, with a need for a global and inclusive approach to establish consensus. Bringing together these methods (both new and old) for regulatory assessment and decision-making will require a concerted effort and orchestration.publishedVersio
Elveovervåkningsprogrammet 2022 – vannkvalitetstilstand og ‐trender
Get PDFProsjektleder: Øyvind KasteIn the Norwegian River Monitoring Programme (in Norwegian: Elveovervåkingsprogrammet) 20 rivers along the Norwegian coast are monitored for physical and chemical parameters. This report presents the current status (2022) and long‐term (1990‐ 2022) trends in suspended particles, organic matter, nutrients, and metals. EU Water Framework Directive priority substances and river basin‐specific pollutants (trace metals and organic pollutants) from five rivers in south‐ and southwestern Norway are compared with annual average environmental quality standards (AA‐EQS). The report also presents light absorbance indices for characterisation of dissolved organic matter (DOM) quality in the rivers, and high‐frequency measurements of water temperature, pH, conductivity, turbidity and fluorescent DOM (FDOM) at four river stations.Norwegian Environment AgencypublishedVersio
Estimation of ecosystem respiration and photosynthesis in supersaturated stream water downstream of a hydropower plant
Get PDFThe estimation of whole stream metabolism, as determined by photosynthesis and respiration, is critical to our understanding of carbon cycling and carbon subsidies to aquatic food-webs. The mass development of aquatic plants is a worldwide problem for human activities and often occurs in regulated rivers, altering biodiversity and ecosystem functions. Hydropower plants supersaturate water with gases and prevent the use of common whole stream metabolism models to estimate ecosystem respiration. Here we used the inert noble gas argon to parse out biological from physical processes in stream metabolism calculations. We coupled the O2:Ar ratio determined by gas chromatography in grab samples with in-situ oxygen concentrations measured by an optode to estimate aquatic plant photosynthesis and ecosystem respiration during supersaturation events through a parsimonious approach. The results compared well with a more complicated two-station model based on O2 mass balances in non-supersatured water, and with associated changes in dissolved CO2 (or dissolved inorganic carbon). This new method provides an independent approach to evaluate alternative corrections of dissolved oxygen data (e.g. through the use of total dissolved gases) in long term studies. The use of photosynthesis-irradiance models allows the determination of light parameters such as the onset of light saturation or low light use efficiency, which could be used for inverse modelling. The use of the O2:Ar approach to correct for oversaturation may become more applicable with the emergence of portable mass inlet mass spectrometers (MIMS). Photosynthesis was modest (2.9-5.8 g O2 m2 day−1) compared to other rivers with submerged vegetation, likely indicating nutrient co-limitations (CO2, inorganic N and P). Respiration was very low (-2.1 to -3.9 g O2 m2 day−1) likely due to a lack of allochthonous carbon supply and sandy sediment.publishedVersio