NIVA Open Access Archive
Not a member yet
8416 research outputs found
Sort by
Biological effects monitoring of a thermomechanical cleaned cuttings discharge from the Johan Sverdrup installation
Get PDFProsjektleder Steven BrooksThe following study describes an integrated biological effects monitoring programme using field transplanted mussels to determine the potential effects of thermomechanical cleaned cuttings (TCC) discharged from the Johan Sverdrup installation in the North Sea. Chemical body burden (PAHs, metals) and a suite of biological effects markers were measured in mussels positioned at strategic locations in the Johan Sverdrup field for 6-7 weeks and compared to two reference locations and a day zero (T0) group. The biomarkers measured in the mussels included: condition index (CI); stress on stress (SoS); micronuclei (MN); lysosomal membrane stability (LMS); metallothionein (MT) and gill and digestive gland histology. Based on oceanographic parameters, the DREAM model was employed to predict, and then later confirm, the direction of the TCC plume during the discharge period. Exposure to the TCC was limited to a 3-day window at the end of the mussel exposure but this was considered representative of the sporadic nature of the TCC discharge. PAH body burden in mussels was low in all mussel groups positioned at the Johan Sverdrup installation, although slightly above the reference and day zero mussel groups. Metal concentrations were either on or below the lower limit of the Norwegian classification scale for metal concentrations in mussel tissue indicating insignificant risk. Overall, the biomarker responses were considered low and did not differentiate significantly between the mussel groups. The Principal Component Analysis (PCA) showed no clear association between the chemical and biological responses in mussels and proximity to the Johan Sverdrup installation. The short duration of exposure to the TCC discharge may be partly responsible for the lack of chemical accumulation and biological response observed.EquinorpublishedVersio
Spatio-Temporal Variability of Suspended Particulate Matter in a High-Arctic Estuary (Adventfjorden, Svalbard) Using Sentinel-2 Time-Series
Get PDFArctic coasts, which feature land-ocean transport of freshwater, sediments, and other terrestrial material, are impacted by climate change, including increased temperatures, melting glaciers, changes in precipitation and runoff. These trends are assumed to affect productivity in fjordic estuaries. However, the spatial extent and temporal variation of the freshwater-driven darkening of fjords remain unresolved. The present study illustrates the spatio-temporal variability of suspended particulate matter (SPM) in the Adventfjorden estuary, Svalbard, using in-situ field campaigns and ocean colour remote sensing (OCRS) via high-resolution Sentinel-2 imagery. To compute SPM concentration (CSPMsat), a semi-analytical algorithm was regionally calibrated using local in-situ data, which improved the accuracy of satellite-derived SPM concentration by ~20% (MRD). Analysis of SPM concentration for two consecutive years (2019, 2020) revealed strong seasonality of SPM in Adventfjorden. Highest estimated SPM concentrations and river plume extent (% of fjord with CSPMsat > 30 mg L−1) occurred during June, July, and August. Concurrently, we observed a strong relationship between river plume extent and average air temperature over the 24 h prior to the observation (R2 = 0.69). Considering predicted changes to environmental conditions in the Arctic region, this study highlights the importance of the rapidly changing environmental parameters and the significance of remote sensing in analysing fluxes in light attenuating particles, especially in the coastal Arctic Ocean.publishedVersio
Determining the effects of the discharge effluent from the Karmøy aluminium smelter using an integrated biological effects approach
Get PDFProsjektleder Ailbhe MackenThe report describes a monitoring programme using field transplanted mussels to determine the potential biological effects of the effluent discharge from the Karmøy aluminium smelter operated by Hydro Aluminium in Norway. Chemical body burden (54 PAH and metal concentrations) and a suite of biological effects markers were measured in mussels positioned at known distances and at two depths from the aluminium smelters discharge for a period of 8 weeks. In addition, chemical concentrations of the sediment were also measured within the fjord to evaluate the impact of the aluminium smelter on the local marine environment. The highest PAH and metal contamination of the sediment was observed at station 4, a sheltered lagoon 1-1.5 km south of the smelter (Nordalsvågen), and also elevated at station 3, 500 m south of the smelter. PAH contamination in mussels at the closest stations to the aluminium smelter reflected the PAH profiles of the sediment concentrations at each station. This was not true for metals, which were relatively low in all mussels. The PAH concentration in mussels 2 m above the seafloor (bottom), were higher than mussels 5 m from the surface (top/surface) for three out of the four stations. Despite the accumulation of PAH in the mussels, the five biomarker responses were low and overall did not differentiate significantly between the mussel groups. The Principal Component Analysis (PCA) found no clear association between the impact of PAHs and metals with the biological responses in mussels, even in mussels placed closest to the aluminium smelter.Aluminiumindustriens Miljøsekretariat (AMS)publishedVersio
Stream restoration and ecosystem functioning in lowland streams
Get PDFRestoration has been increasingly applied over the last decades as a way to improve the ecological conditions in stream ecosystems, but documentation of the impact of restoration on ecosystem functions is sparse. Here, we applied a space-for-time approach to explore effects of stream restoration on metabolism and organic matter decomposition in lowland agricultural streams. We included stream reaches that were restored >10 years ago and compared ecosystem functioning in these streams with those in channelized and naturally meandering stream reaches from the same geographical region. Specifically, we tested the following hypotheses: 1) rates of stream metabolism (gross primary production, GPP, and ecosystem respiration, ER) and organic matter decomposition in restored reaches resemble rates in naturally meandering reaches more than rates in channelized stream reaches and 2) higher resemblance in ecosystem metabolism and organic matter decomposition between restored reaches and meandering reaches can be attributed to the improved physical habitat conditions in the restored stream reaches. Overall, we did not find that stream metabolism or organic matter decomposition differed among restored, channelized and naturally meandering stream reaches even though habitat conditions differed among the three stream types. Instead, we found a large variation in ecosystem function characteristics across all sites. When analyzing all stream types combined, we found that GPP increased with increasing plant coverage and that ER increased with increasing stream size and with the coverage of coarse substratum on the stream bottom. Organic matter decomposition, on the other hand, only slightly increased with the number of plant species and declined with increasing concentrations of nutrients. Overall, our findings suggest that physical habitat improvements in restored stream reaches can affect ecosystem functions, but also that the restoration outcome is context-dependent since many of the physical characteristics playing a role for the measured functions were only to some extent affected by the restoration and/or clouded by interference with factors operating at a larger-scale.publishedVersio
Species composition and abundance of free-living turbellarians in three different wetlands in Southern Brazil
Get PDFFree-living turbellarians mostly live in marine and freshwater environments, but they have been little considered in ecological studies. The coastal plain in southern Brazil harbors a diverse fauna and flora, but only a few studies have related environmental factors to the abundance, richness, and distribution of turbellarians. Hence, we analyzed the structure of turbellarian communities in floating vegetation in three differently sized limnic environments. We aimed to determine differences in abundance, density, and richness of turbellarians among these habitats in relation to environmental factors. We found 1,225 turbellarians (34 species) distributed among 6 taxa. The most abundant was Tricladida with 49.4% relative abundance; the remaining (Catenulida, Dalytyphloplanida, Macrostomorpha, Kalyptorhynchia, and Prorhynchida) were less abundant. We found no significant differences among population parameters and environments. Small shallow lakes are a potentially rich environment, while water channels are the richest environment. Larger shallow lakes are not very diverse for turbellarians. Similarities regarding turbellarian communities among close limnic systems could be explained by the connectivity of bodies of water that presents similar aquatic macrophytes and hydrological subsystems, while larger shallow lakes have a different community because they have their own contributing basin and could be influenced by other factors.publishedVersio
Hot Vents Beneath an Icy Ocean: The Aurora Vent Field, Gakkel Ridge, Revealed
Get PDFEvidence of hydrothermal venting on the ultra-slow spreading Gakkel Ridge in the Central Arctic Ocean has been available since 2001, with first visual evidence of black smokers on the Aurora Vent Field obtained in 2014. But it was not until 2021 that the first ever remotely operated vehicle (ROV) dives to hydrothermal vents under permanent ice cover in the Arctic were conducted, enabling the collection of vent fluids, rocks, microbes, and fauna. In this paper, we present the methods employed for deep-sea ROV operations under drifting ice. We also provide the first description of the Aurora Vent Field, which includes three actively venting black smokers and diffuse flow on the Aurora mound at ~3,888 m depth on the southern part of the Gakkel Ridge (82.5°N). The biological communities are dominated by a new species of cocculinid limpet, two small gastropods, and a melitid amphipod. The ongoing analyses of Aurora Vent Field samples will contribute to positioning the Gakkel Ridge hydrothermal vents in the global biogeographic puzzle of hydrothermal ventspublishedVersio
Tiltaksorientert overvåking i vannområde Mjøsa. Hovedrapport for 2021
Get PDFProsjektleder Jan-Erik ThraneEn samlet vurdering av planteplankton, fosfor og siktedyp ved fire stasjoner i Mjøsa viser at hovedvannmassene var i god økologisk tilstand i 2021. Ved Skreia og i Furnesfjorden var det likevel noe mer alger enn miljømålet, med alge-biovolum i moderat tilstand. I juli var det en stor oppblomstring av den potensielt toksinproduserende cyanobakterien Dolichospermum lemmermannii, men ingen cyanotoksiner ble påvist. Middelkonsentrasjonene av total-fosfor på senvinteren (<3,5 μg P/l) og gjennom vekstsesongen (4,5–5,5 μg P/l) tilfredsstilte det lokale miljømålet og var i god tilstand ved alle stasjoner. Generelt var konsentrasjonene av fosfor høyere i perioden 2009–2016, sammenliknet med periodene 2002–2008 og etter 2017. Dette skyldes i hovedsak store tilførsler av næringssalter med flommene i 2011, 2013 og 2014. Det var klart vann i Mjøsa i 2021, og gjennomsnittlig siktedyp var høyere enn det lokale miljømålet på 8 m ved Skreia og Kise (svært god tilstand) og 7,2 m (god tilstand) i Furnesfjorden. Høyt siktedyp og lave fosforkonsentrasjoner i 2021 skyldes trolig at det var et uvanlig tørt år med lite avrenning. Dette gjenspeiles også i samlet elvetilførsel av fosfor til Mjøsa, som ble estimert til 68 tonn og er blant de laveste transportene i tidsserien. Fosforkonsentrasjonen i tilløpselvene viste god/svært god tilstand, men nivåene av nitrogen og E.coli var høye, unntatt i Lågen. Biologiske undersøkelser viste moderat tilstand for begroing eller heterotrof begroing i Vikselva og nedre deler av Hunnselva og Svartelva, men god eller svært god tilstand ved de resterende stasjonene og i Lågen. Nivåene av de allestedsnærværende stoffene kvikksølv og PBDE i fisk fra Hunnselva og Vikselva overskred vanndirektivets grenseverdier, men nivåene av kvikksølv var under EUs omsetningsgrense.publishedVersio
Aggregate exposure pathways for microplastics (mpAEP): An evidence-based framework to identify research and regulatory needs
Get PDFMicroplastics as emerging contaminants have been detected from peaks to poles. High concerns on the risks of microplastic pollution to humans and ecosystems have therefore been raised in the past decade. While a large number of studies have been conducted to investigate the environmental levels and toxicity of microplastics, the information generated to support risk assessment is fragmented and the coherence between different types of study is largely lacking. Here we introduced the Aggregate Exposure Pathway (AEP), a conceptual framework originally proposed for chemical exposure assessment, to facilitate organization, visualization and evaluation of existing information generated from microplastic research, and to efficiently identify future knowledge and regulatory needs. A putative microplastic AEP network (mpAEP) was developed to demonstrate the concept and model development strategies. Two mpAEP case studies, with polyethylene (PE) as a prototype, were then presented based on existing environmental exposure data collected from the Changjiang Estuary and the East China Sea (Case I), and the Oslo Fjord (Case II), respectively. Weight of evidence (WoE) assessment of the mpAEPs were performed for evaluating the essentiality, theoretical plausibility, empirical evidence and quantitative understanding of the evidence and relationships in the AEPs. Both cases showed moderate/high WoE to support the strength of the models, whereas also displayed clear knowledge gaps, thus providing guidance for future investigations and regulations. The mpAEP framework introduced herein presents a novel strategy for organizing fragmented information from diverse types of microplastic research, enhancing mechanistic understanding of causal relationships and facilitating the development of quantitative prediction models for research and regulation in the future.publishedVersio
ØKOKYST – DP Norskehavet Sør, Årsrapport 2021
Get PDFProsjektansvarlig Anne DeiningerOvervåkingsprogrammet "Økosystemovervåking i Kystvann – Økokyst" har til hensikt å overvåke miljøtilstanden langs norskekysten i henhold til vannforskriften. Økokyst delprogram Norskehavet Sør dekker kyststrekningen fra Ulsteinvik i sør til Helgeland i nord. Av de 11 vannforekomster som kunne klassifiseres, fikk 1 “svært god” tilstand, 7 «god» tilstand og 3 «moderat» tilstand. Tilstanden var minst “god” for makroalger, bløtbunnsfauna og planteplankton, mens det var støtteparameterne og ålegress som trakk ned tilstanden på stasjonene hvor samlet tilstand kun ble «moderat».publishedVersio
Tiltaksorientert overvåkning i Follafoss havneområde og Beitstadfjorden i 2021 for MM FollaCell AS og SalMar Settefisk AS
Get PDFProsjektleder/Hovedforfatter Gunhild BorgersenNIVA har gjennomført tiltaksorientert overvåking i henhold til vannforskriften i Beitstadfjorden på oppdrag fra MM FollaCell AS og SalMar Settefisk AS. Hensikten med overvåkingen har vært å identifisere hvorvidt bedriftenes utslipp påvirker vannforekomstenes økologiske og kjemiske tilstand. Overvåkingen omfattet undersøkelse av bunnfauna, makroalger, planteplankton (klorofyll a), næringssalter, vannregionspesifikke stoffer og prioriterte stoffer i biota og sediment. I vannforekomst «Follafoss havneområde» var den økologiske tilstanden «god» for makroalger på alle tre stasjoner. I vannforekomst «Beitstadfjorden» var den økologiske tilstanden «moderat» for planteplankton. For bunnfauna var den økologiske tilstanden «svært god» på stasjon SCE5 og «god» på stasjon SCE6 (nærmest utslippet). Stasjon SCE6 hadde også svært høyt innhold av organisk karbon og nitrogen i sedimentet. Innholdet av de prioriterte stoffene kvikksølv, bly, kadmium og nikkel i sediment ga «god» kjemisk tilstand på de to sedimentstasjonene». Kjemisk tilstand basert på analyser av kvikksølv fra tre blåskjellstasjoner ble også klassifisert til «god». Det var ingen overskridelser av EQS-verdier for vannregionspesifikke stoffer.publishedVersio