Trends and patterns in surface water chemistry in Europe and North America between 1990 and 2020, with a focus on calcium

Prosjektleder: Rolf David VogtThe report presents trends in major anions and cations, pH, TOC and bicarbonate in surface waters in Europe and North America from 1990 to 2020. Special attention is given to trends in calcium, which showed some unexpected increases. The trends in calcium are analysed in relation to changes in bicarbonates, organic anions, and deposition loads. The surface waters show strong signs of chemical recovery.Norwegian Ministry of Climate and Environment, United Nations Economic Commission for Europe (UNECE)publishedVersio

Overvåking av Vestvannet og Borredalsdammen i Viken, 2023, NIVA-rapport 7935-2024

Prosjektleder: Andreas BallotNIVA og FREVAR har gjennomført overvåking av vannkvaliteten i Vestvannet i Sarpsborg og Borredalsdammen i Fredrikstad i 2023, med fokus på utvalgte fysisk-kjemiske parametere og planteplankton. Gjennomsnittlig konsentrasjon av totalt fosfor og totalt nitrogen gikk opp i Vestvannet-B og Borredalsdammen i 2023 sammenlignet med 2022. Algebiomassen og klorofyll a-konsentrasjonene var høyere i Vestvannet-B og Borredalsdammen i 2023 sammenlignet med 2022. Algesamfunnet var hovedsakelig sammensatt av arter som er vanlige i lavlandsinnsjøer. I noen måneder ble det registrert lave mengder av potensielt toksinproduserende cyanobakterier Microcystis, Planktothrix og Dolichospermum, men microcystin (det mest produserte toksinet) ble ikke påvist. Generelt var det lite cyanobakterier i både Vestvannet-B og Borredalsdammen sammenlignet med total algebiomasse. Vestvannet-B og Borredalsdammen havnet i svært god økologisk tilstand iht. vannforskriften. Vestvannet-B og Borredalsdammen vurderes som godt egnet til drikkevann med hensyn til microcystin. I en totalvurdering av vannenes egnethet som drikkevann vurderes derimot begge vannene til ikke egnet grunnet høye fargetall, men siden FREVAR utfører omfattende behandling av vannet vil det likevel kunne leveres drikkevann av god kvalitet.Fredrikstad Vann, Avløp og Renovasjonsforetak (FREVAR KF)publishedVersio

Microcystin profiles in European noble crayfish Astacus astacus and water in Lake Steinsfjorden, Norway

Lake Steinsfjorden, an important noble crayfish (Astacus astacus) habitat, is often affected by blooms of Planktothrix spp. that produce microcystins (MCs). A poor correlation between MCs by ELISA in the water and in crayfish tissue in a study in 2015 prompted further investigation by LC–HRMS. LC–HRMS analyses of filters from water samples and on selected crayfish tissue extracts from the 2015 study revealed the presence of known and previously unreported MCs. Crayfish samples from May and June 2015 were dominated by MCs from the Planktothrix bloom, whereas in September novel MCs that appeared to be metabolites of MC-LR were dominant, even though neither these nor MC-LR were detected in the water in 2015. A water sample from October 2016 also showed MCs typical of Planktothrix (i.e., [d-Asp3]- and [d-Asp3,Dhb7]MC-RR and -LR), but low levels of MC-RR and MC-LR were detected in the lake water for the first time. In late summer and autumn, the MC profiles of crayfish were dominated by the homonorvaline (Hnv) variant MC-LHnv, a putative metabolite of MC-LR. Taken together, ELISA, LC–HRMS and previous PCR analyses showed that although Planktothrix was part of the crayfish diet, it was not the sole source of MCs in the crayfish. Possibly, crayfish in Lake Steinsfjorden may be ingesting MCs from benthic cyanobacteria or from contaminated prey. Therefore, information on the cyanobacterial or MC content in the water column cannot safely be used to make predictions about MC concentrations in the crayfish in Lake Steinsfjorden. Interestingly, the results also show that targeted LC–MS analysis of the crayfish would at times have underestimated their MC content by nearly an order of magnitude, even if all previously reported MC variants had been included in the analysis.publishedVersio

Klorbehandling i øvre Driva 2023 – Supplerende tiltak i hovedelv og utvalgte sidevassdrag oppstrøms fiskesperra i Driva

Prosjekleder: Anders Gjørwad HagenI august 2023 mottok gruppen «Gyroklor» en bestilling på klorbehandling i øvre deler av Driva som skulle gjennomføres i løpet av september 2023. I henhold til bestillingen var formålet med denne behandlingen «(…) å redusere smittetrykket i Driva etter påvising av laks (Salmo salar) og Gyrodactylus salaris på oversiden av fiskesperra, så langt det er praktisk mulig». Den reelle behandlingsstrekningen ble ut fra dette definert med nederste doseringsstasjon ved Vikabrua og øvre doseringspunkt ovenfor Mågålaupet. I tillegg ble det dosert kloramin i sideelvene Vinstra og Ålma for å håndtere fortynningseffekten fra disse. Behandlingsperioden var på seks dager. I løpet av denne perioden var målsettingen å oppnå minimum 90 mikrogramdøgn aktivt klor i alle behandlede vannveier. Det ble gjort jevnlige målinger for å følge opp effekten av alle doseringspunkter. Det ble også gjort undersøkelser for å påvise hvor langt behandlingseffekten strakk seg fra nederste doseringspunkt. Analysene viste at det ble oppnådd en samlet behandlingseffekt på mer enn 90 mikrogramdøgn ved alle prøvepunkter. Sannsynligheten for at det skal ha overlevd G. salaris i behandlingsområdet er ansett som svært liten, og behandlingen var vellykket.Veterinærinstituttet i TrondheimpublishedVersio

Klasseromsmodellsystem for akvaponi i utdanningen [NIVA-rapport 7930-2024]

Prosjektleder: Gabrielle HairabedianThis represents a classroom model system (CMS) or instructional tool for teachers to implement collaborative learning through different modules relevant to aquaponics. It can be adapted and customized as needed and utilizes aquaponics as a learning arena to explore existing global challenges. It links with the Small-Scale Urban Pilot Installation developed within the USAGE project in Norway at Natur videregående skole (Natur VGS), a high school/upper secondary school in Oslo. The Norwegian National Curriculum has provided an overall point of departure for this work along with specified subjects and curriculum at Natur VGS. The varying subject curricula selected include: Agriculture, fishing and forestry; Natural science; English; Mathematics; Agriculture and horticulture; Chemistry; and Biology. Six topical teaching and learning modules provide background information and examples of activities and discussion topics that connect to aquaponics. The modules include: Sustainability; Plant growth, health and development; Animal welfare; Water chemistry and quality; Urban farming; and Economy and business operations. Aquaponics provides an opportunity for interdisciplinary learning across many subjects and through aquaponics, there is the potential to enrich classes in Science, Technology, Engineering, and Mathematics (STEM). This CMS aims to provide standard methods for the implementation of aquaponics in teaching or as a learning arena for high school/upper secondary school classrooms in Norway.EEA/Norway Grants 2014-2021 through NCBR NOR/IdeaLab/USAGE/0004/2020publishedVersio

No additional stress of sublethal gas supersaturation in a landlocked population of Atlantic salmon (Salmo salar) exposed to environmental acidification

The landlocked Atlantic salmon population “bleke” faces extinction due to environmental acidification (EA) and hydropower expansion in the Norwegian river Otra. Despite of restoration, unexpected mortality has been reported for this population, possibly due to gas bubble trauma (GBT) from gas supersaturation (GSS) downstream of hydroelectric plants, or EA induced aluminum toxicity. In this study, we applied the allostasis concept to investigate interactions between EA and GBT. This concept comprises additive effects of stressors, which can lead to allostatic overload. Stress coping mechanisms become maladaptive in such situations, which can be indicated by an inability to mount a proper cortisol response in fish. Fish were exposed to sublethal levels of simulated EA (SEA), GSS (a total gas pressure; TGP; of 110%) or a combination of these stressors for six days. Effects on allostatic load were subsequently investigated by assessing the cortisol response to an acute stress test. SEA increased cortisol responsiveness and GSS induced clinical signs of GBT, but no interacting effects between GSS and SEA were observed. This suggests that that 110% TGP did not have an additive effect on the allostatic load imposed by SEA.publishedVersio

Karakterisering og kildesporing av polysykliske aromatiske substanser (PAC) i sediment rundt Mongstad

Prosjektleder: Merete GrungPolysykliske aromatiske substanser (PAC) ble målt i sedimentprøver fra 16 stasjoner i Fensfjorden nær Mongstad oljeraffineri. PAC‐konsentrasjoner ble vurdert mot klassegrenser i vannforskriften, både AA‐EQS og MAC‐EQS. Ingen stasjoner overskred klassegrense 3 for sumPAH16, men enkelte PAC overskred klassegrense 3. Ingen PAC overskred MAC‐EQS. Ved en hierarkisk gruppering ble det identifisert 3‐4 hovedgrupper av stasjoner basert på konsentrasjon og PAC‐mønster. Ulike indekser viste statistiske forskjeller mellom noen av gruppene, spesielt med henblikk petrogene og pyrogene PAC. Ved stasjon Mo55 ble det påvist høyt innhold av krysener (C) relativt til andre PAC. En C‐ratio (krysener/andre PAC) viste at ratioen var høy ved Mo55. C‐ratio var lavere i området rundt Mongstad, og lavest for stasjoner på dypet og stasjoner lengre unna Mongstad. Resultatene fra sedimentanalyser antyder at Fensfjorden har en pyrogen bakgrunn av PAC som blandes med et petrogent innslag fra Mongstad. Også i utslippsvann fra Mongstad var krysen dominerende. Lignende ratioer av krysener mot tunge PAC ble gjenfunnet i nærstasjoner av sediment til Mongstad, men ikke fra sedimentstasjoner dypt i Fensfjorden. Dette styrker konklusjonen fra sedimentanalysene med en pyrogen bakgrunn i Fensfjorden som blandes med et petrogent innslag fra Mongstad.Mongstad, Equinor ASApublishedVersio

Biological intercalibration: Invertebrates 2023

Prosjektleder: Kari AustnesThe ICP Waters biological intercalibration of invertebrates was executed to harmonise taxonomic work across countries and is of high value in programmes where the focus is on community analyses, e.g., for the classification of ecological status according to the EU Water Framework Directive. The 27th biological intercalibration of invertebrates in ICP Waters included four participants. A total 99.9 % of the species and 99.9 % of the genera were correctly identified in 2023. The mean Quality assurance index (Qi) ranged from 98.1 to 100.0. The results show that the average Qi has remained above 80% since 1992, suggesting skilled taxonomists in the laboratories affiliated to ICP Waters.Norwegian Ministry of Climate and Environment, United Nations Economic Commission for Europe (UNECE)publishedVersio

Does sedation with AQUI-S® mitigate transport stress and post transport mortality in ballan wrasse (Labrus bergyltae)?

Ballan wrasse (Labrus bergylta) are commonly used as cleaner fish in salmon farms as a biological treatment to mitigate sea lice infestation. Improved welfare for cleaner fish both during production of these fish and when in sea-cages with salmon is crucial for the industry’s development. A common operational procedure in ballan wrasse production is transporting juveniles from one land-based farm to another for further on-growing. Episodes of increased mortality have been reported after such transportations. In this study, the relationship between transport stress and post-transport mortality at the on-growing facility was examined. It was also investigated if light sedation with AQUI-S® can mitigate stress during transport. Stress was quantified by measuring cortisol release rate to the tank water during transport. This was investigated in 10 commercial live carrier truck transports (6 without AQUI-S® sedation and 4 with sedation during loading and transport). The total time of transport varied between 12 and 21 h. In general, mortality was significantly higher (1.0 ± 0.6% day−1) the first five days post-transport compared to 15–20 days post transport (0.5% day−1). There was also a strong relationship between fish weight at transport and post-transport mortality, where higher mean weight at transport reduced mortality. In contrast to what was expected, AQUI-S® treatment during transport procedures increased cortisol excretion rate, suggesting a stimulating effect of AQUI-S® on the stress axis in ballan wrasse. Considering these results, the value of using AQUI-S® to reduce stress during transport of juvenile ballan wrasse might be questioned. However, there was no relationship between cortisol release rate during transport and post-transport mortality. Furthermore, this study emphasizes that water cortisol measurements can be used as a none-invasive tool for monitoring stress and can be integrated into the welfare evaluation during commercial fish transports.publishedVersio

Hydrogen sulphide dynamics in recirculating aquaculture systems with moving or fixed bed biofilters: A case study in two commercial salmon smolt producing farms in Norway

Sudden mass mortalities of fish reared in recirculating aquaculture systems (RAS) have occurred in recent years. High total dissolved sulphide (H2S + HS- + S2-) levels in the rearing water have been suggested as an underlaying factor for such mass mortalities. However, limited information is available regarding H2S dynamics in commercial aquaculture production facilities. In this case study, we present H2S dynamics in the rearing water of two commercial salmon post-smolt (150–250 g) RAS facilities equipped with different biofilters: one RAS with fixed bed biofilters (fRAS) and the other RAS with moving bed biofilters (mRAS). The farms operated at different water exchange rates and cumulative feed load but were otherwise comparable in terms of biomass and feed loading throughout the monitoring period. Self-calibrating, automatic gas-phase H2S sensors were installed at three locations per farm: after the fish tanks, after the biofilters and after the degassers and operated for a period of approximately 70 days in both farms. H2S was observed at maximum daily average of 0.6 µg/L in all locations monitored in the two RAS facilities and no significant fish mortality was reported during the monitoring period. In the fRAS, H2S concentration dynamics showed that there was a net concentration increase after the fish tanks and after the biofilters, and a net concentration decrease after the degassers. Furthermore, in the fRAS, backwashing of fixed bed biofilter chambers caused a slight increase in H2S after the biofilters. In the mRAS, there was a net positive increase in H2S after the fish tanks, and a net concentration decrease after the biofilters and degassers. Moreover, generally, H2S concentration in RAS seemed to be unrelated to feeding or fish biomass. Thus, this study suggests that the main contributing factors to H2S dynamics in RAS are biofilter design, system, and tank water exchange rates and, and potentially aeration and turbulence within each compartment.publishedVersio