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Interlaboratory Validation of Toxicity Testing Using the Duckweed Lemna minor Root-Regrowth Test
Get PDFThe common duckweed (Lemna minor), a freshwater monocot that floats on the surfaces of slow-moving streams and ponds, is commonly used in toxicity testing. The novel Lemna root- regrowth test is a toxicity test performed in replicate test vessels (24-well plates), each containing 3 mL test solution and a 2–3 frond colony. Prior to exposure, roots are excised from the plant, and newly developed roots are measured after 3 days of regrowth. Compared to the three internationally standardized methods, this bioassay is faster (72 h), simpler, more convenient (requiring only a 3-mL) and cheaper. The sensitivity of root regrowth to 3,5-dichlorophenol was statistically the same as using the conventional ISO test method. The results of interlaboratory comparison tests conducted by 10 international institutes showed 21.3% repeatability and 27.2% reproducibility for CuSO4 and 21.28% repeatability and 18.6% reproducibility for wastewater. These validity criteria are well within the generally accepted levels of <30% to 40%, confirming that this test method is acceptable as a standardized biological test and can be used as a regulatory tool. The Lemna root regrowth test complements the lengthier conventional protocols and is suitable for rapid screening of wastewater and priority substances spikes in natural waters.publishedVersio
To veier mot god miljøtilstand. En sammenlikning av EU sitt havstrategidirektiv med de norske havforvaltningsplanene
Get PDFProsjektleder Gunnar SanderEUs havstrategidirektiv (MSFD) og de norske havforvaltningsplanene er eksempler på at økosystembasert forvaltning kan settes ut i praksis. Mens MSFD er en lov som gir rammer for de europeiske kyststatene, er de norske planene politiske instrumenter som i liten grad har formaliserte regler. Det er store likheter i formulering av mål for og måling av havets miljøtilstand. Det gir en felles innfallsvinkel til å lage rapporter om tilstanden og drive overvåking. Norge vil derfor neppe ha problemer med å rapportere miljødata i regionalt samarbeid med EU-land, som i OSPAR. I utarbeidelsen av planer er det derimot klare forskjeller. MSFD har krav om å vurdere både effekt, effektivitet og bieffekter av tiltak, og forslag til tiltaksprogram skal ut på offentlig høring. Forvaltningsplanene utarbeides derimot i en lukket prosess i sentralforvaltningen, uten krav om tiltaksanalyser. Det er derfor vanskelig å bedømme om politikken som regjeringen legger fram vil bidra til å nå målene. På bakgrunn av de mest iøynefallende forskjellene til MSFD anbefaler vi de ansvarlige for de norske planene å vurdere å: 1)formalisere prosedyrer og metoder; 2) innføre tiltaksplanlegging; 3) legge forslag til plan ut på høring; 4) innføre evaluering og 5)samarbeide faglig med EU om felles problemstillinger.publishedVersio
Passive Sampling Helps the Appraisal of Contaminant Bioaccumulation in Norwegian Fish Used for Regulatory Chemical Monitoring
Get PDFHexachlorobenzene (HCB), listed on the Stockholm Convention on persistent organic pollutants and regulated as a hazardous priority pollutant by the Water Framework Directive (WFD), is ubiquitously distributed in the environment and assumed to mildly biomagnify in aquatic foodwebs. The proposal to include trophic magnification factors (TMFs) in the procedure for comparing contaminant levels in biota at different trophic levels (TLs) with WFD environmental quality standards requires adequate selection of TMFs. In the first step of our study, we compared two independently obtained datasets of pentachlorobenzene (PeCB) and HCB concentration ratios from passive sampling (PS) in water and in fish through routine monitoring programs in Norway to evaluate possible biomagnification. In this procedure, PeCB is used for benchmarking the bioconcentration in fish, and the observed HCB/PeCB ratios in fish are compared with ratios expected in the case of (i) HCB bioconcentration or (ii) biomagnification using published TMF values. Results demonstrate that it is not possible to confirm that HCB biomagnifies in fish species that would be used for WFD monitoring in Norway and challenges the proposed monitoring procedures for such compounds in Norwegian or European waters. In the second step, fish-water chemical activity ratios for HCB and PeCB as well as for polychlorinated biphenyls where biota and PS were conducted alongside were calculated and found to rarely exceed unity for cod (Gadus morhua), a fish species with a TL of approximately 4.publishedVersio
Land Use Change to Reduce Freshwater Nitrogen and Phosphorus will Be Effective Even with Projected Climate Change
Get PDFRecent studies have demonstrated that projected climate change will likely enhance nitrogen (N) and phosphorus (P) loss from farms and farmland, with the potential to worsen freshwater eutrophication. Here, we investigate the relative importance of the climate and land use drivers of nutrient loss in nine study catchments in Europe and a neighboring country (Turkey), ranging in area from 50 to 12,000 km2. The aim was to quantify whether planned large-scale, land use change aimed at N and P loss reduction would be effective given projected climate change. To this end, catchment-scale biophysical models were applied within a common framework to quantify the integrated effects of projected changes in climate, land use (including wastewater inputs), N deposition, and water use on river and lake water quantity and quality for the mid-21st century. The proposed land use changes were derived from catchment stakeholder workshops, and the assessment quantified changes in mean annual N and P concentrations and loads. At most of the sites, the projected effects of climate change alone on nutrient concentrations and loads were small, whilst land use changes had a larger effect and were of sufficient magnitude that, overall, a move to more environmentally focused farming achieved a reduction in N and P concentrations and loads despite projected climate change. However, at Beyşehir lake in Turkey, increased temperatures and lower precipitation reduced water flows considerably, making climate change, rather than more intensive nutrient usage, the greatest threat to the freshwater ecosystem. Individual site responses did however vary and were dependent on the balance of diffuse and point source inputs. Simulated lake chlorophyll-a changes were not generally proportional to changes in nutrient loading. Further work is required to accurately simulate the flow and water quality extremes and determine how reductions in freshwater N and P translate into an aquatic ecosystem response.publishedVersio
Tiltaksorientert overvåking av Ranfjorden i 2021. Overvåking for Mo Industripark AS, Celsa Armeringsstål AS, Elkem ASA Rana, Ferroglobe Mangan Norge AS, Miljøteknikk Terrateam AS, Rana Gruber AS og Rana kommune
Get PDFProsjektleder Sigurd ØxnevadNIVA har gjennomført tiltaksorientert overvåking av Ranfjorden i 2021 på oppdrag for Mo Industripark AS, Celsa Armeringsstål AS, Elkem ASA Rana, Ferroglobe Mangan Norge, Miljøteknikk Terrateam AS, Rana Gruber AS og Rana kommune. Overvåkingsprogrammet er utført i henhold til Vannforskriften på bakgrunn av hvilke stoffer som bedriftene og kommunen har utslipp av til Ranfjorden. Hensikten med overvåkingen har vært å identifisere hvorvidt utslippene påvirker vannforekomstens kjemiske og økologiske tilstand. Kjemisk tilstand ble bestemt ved analyse av miljøgifter i prøver av blåskjell fra tre stasjoner og i sedimentprøver fra fire stasjoner. Det ble gjort analyser av metaller (arsen, bly, kadmium, kobber, krom, kvikksølv, nikkel og sink), polysykliske aromatiske hydrokarboner (PAH), polyklorerte bifenyler (PCB), perfluorerte alkylstoffer (PFAS) og tinnorganiske forbindelser. Det ble også analysert for flotasjonskjemikaliet Lilaflot D817M og total mengde hydrokarboner (THC) i sedimentprøver. Økologisk tilstand ble bestemt ved overvåking av bløtbunnsfauna på tolv stasjoner. Ni av disse hadde tilstand dårligere enn «god», og utstrekningen av påvirket areal har økt. Kjemisk tilstand for tre av sedimentstasjonene klassifiseres som «ikke god» på grunn av overskridelse av grenseverdier for prioriterte stoffer. Kjemisk tilstand for blåskjellstasjonen nord for Toraneskaia klassifiseres som «ikke god» på grunn av overskridelse av grenseverdi for det prioriterte stoffet benzo(a)pyren. De to andre blåskjellstasjonene var i «god» kjemisk tilstand.publishedVersio
Assessing Tolerance to the Hydrodynamic Exposure of Posidonia oceanica Seedlings Anchored to Rocky Substrates
Get PDFAmong a suite of abiotic and biotic factors, the hydrodynamic regime strongly influences the success of seagrass recruitment through sexual propagules. Uprooting of propagules by drag forces exerted by currents and waves is one of the main causes for the failed establishment and the consequent recruitment. Substrate type and stability play a key role in determining the success of colonization through sexual propagules, as seedling establishment probabilities proved to be significantly higher on rocky bottoms than on unstable unconsolidated substrates. In this research, the current and wave flow intensity that Posidonia oceanica seedlings anchored to rocky substrates can withstand before uprooting were evaluated and the influence of substrate complexity on seedling anchorage success and anchorage strength was investigated. P. oceanica seedlings withstood the current velocity of 70 cm s–1 and increased orbital flow velocities up to 25 cm s–1. Seedling adhesion strength ranged from 3.92 to 29.42 N. Results of the present study corroborate the hypothesis that substrate complexity at scales relevant to the size of propagules is a crucial feature for P. oceanica seedling establishment. The intensity of unidirectional and oscillatory flow that seedlings can withstand without being dislodged assessed in this study support the hypothesis that P. oceanica sexual propagules, once adhered to a consolidated substrate, are able to tolerate high hydrodynamic stress. The results of the present study contribute to re-evaluation of the habitat requirements of P. oceanica, assessing the range of hydrodynamic conditions that this species can tolerate during the early stages of its life history.publishedVersio
Diversified Farming Systems: Impacts and Adaptive Responses to the COVID-19 Pandemic in the United States, Norway and China
Get PDFThe COVID-19 pandemic fully exposed the vulnerability of the global agri-food system to shocks and stresses, highlighting the need for transformation and action to make it more resilient and inclusive. This paper offers a unique insight into the global nature of the COVID-19 pandemic by examining impacts and responses in the agri-food sector within three very distinct contexts, namely the United States, Norway, and China. Focusing on small, diversified farms, the study builds on prior research with the same farmers and support organizations from an on-going collaboration. Firstly, we conducted a short review of policy adaptations to understand how governments, the private sector, non-profit organizations, and communities “stepped up” to provide emergency relief, specialized training, and recovery support for farmers, support that was instrumental in preventing more devastating impacts in all three countries. Secondly, drawing from in-depth interviews with farmers (23) and government and non-governmental support organizations (19), we mapped the vulnerability and resiliency of selected farmers to shocks that severely disrupted traditional supply chains during the COVID-19 pandemic. Data were collected on both the negative and positive impacts of the pandemic to farmer inputs, including labor, operations, and markets, how these changed from the initial lockdowns in early 2020 and through 2021, and on farmer adaptive responses to these impacts. In some contexts, innovation and adaptive responses counteracted negative impacts. We saw diversifying markets, catering to consumer safety concerns, switching to direct and e-markets, hiring in more labor or relying on family labor, and switching to high demand crops and products as the most prominent adaptive responses. Farmers who lacked access to information and government programs, in large part because of language, technology and institutional barriers, missed out on pandemic related opportunities and suffered the most. As we enter the post-pandemic new normal it is important to take stock of lessons learned, and to continue to support those initiatives and innovations that were pivotal not only for weathering the storm, but for building a more inclusive and resilient agri-food system in the long-run.publishedVersio
Kelp carbon sink potential decreases with warming due to accelerating decomposition
Get PDFCycling of organic carbon in the ocean has the potential to mitigate or exacerbate global climate change, but major questions remain about the environmental controls on organic carbon flux in the coastal zone. Here, we used a field experiment distributed across 28° of latitude, and the entire range of 2 dominant kelp species in the northern hemisphere, to measure decomposition rates of kelp detritus on the seafloor in relation to local environmental factors. Detritus decomposition in both species were strongly related to ocean temperature and initial carbon content, with higher rates of biomass loss at lower latitudes with warmer temperatures. Our experiment showed slow overall decomposition and turnover of kelp detritus and modeling of coastal residence times at our study sites revealed that a significant portion of this production can remain intact long enough to reach deep marine sinks. The results suggest that decomposition of these kelp species could accelerate with ocean warming and that low-latitude kelp forests could experience the greatest increase in remineralization with a 9% to 42% reduced potential for transport to long-term ocean sinks under short-term (RCP4.5) and long-term (RCP8.5) warming scenarios. However, slow decomposition at high latitudes, where kelp abundance is predicted to expand, indicates potential for increasing kelp-carbon sinks in cooler (northern) regions. Our findings reveal an important latitudinal gradient in coastal ecosystem function that provides an improved capacity to predict the implications of ocean warming on carbon cycling. Broad-scale patterns in organic carbon decomposition revealed here can be used to identify hotspots of carbon sequestration potential and resolve relationships between carbon cycling processes and ocean climate at a global scale.publishedVersio
Examining the Relevance of the Microplastic-Associated Additive Fraction in Environmental Compartments
Get PDFPlastic contamination is ubiquitous in the environment and has been related to increasing global plastic usage since the 1950s. Considering the omnipresence of additives in plastics, the risk posed by this contamination is related not only to the physical effects of plastic particles but also to their additive content. Until now, most routine environmental monitoring programs involving additives have not considered the presence of these additives still associated with the plastic they were added to during their production. Understanding environmental additive speciation is essential to address the risk they pose through their bioavailability and plastic-associated transport. Here, we present and apply a theoretical framework for sampling and analytical procedures to characterize the speciation of hydrophobic nonionized additives in environmental compartments. We show that this simple framework can help develop sampling and sample treatment procedures to quantify plastic-associated additives and understand additive distribution between plastics and organic matter. When applied to concrete cases, internal consistency checks with the model allowed for identifying plastic-associated additives in a sample. In other cases, the plastic-organic carbon ratio and additive concentration in the matrix are key factors affecting the ability to identify plastic-associated additives. The effect of additive dissipation through diffusion out of plastic particles is also considered.publishedVersio
Volcanically hosted venting with indications of ultramafic influence at Aurora hydrothermal field on Gakkel Ridge
Get PDFThe Aurora hydrothermal system, Arctic Ocean, hosts active submarine venting within an extensive field of relict mineral deposits. Here we show the site is associated with a neovolcanic mound located within the Gakkel Ridge rift-valley floor, but deep-tow camera and sidescan surveys reveal the site to be ≥100 m across—unusually large for a volcanically hosted vent on a slow-spreading ridge and more comparable to tectonically hosted systems that require large time-integrated heat-fluxes to form. The hydrothermal plume emanating from Aurora exhibits much higher dissolved CH4/Mn values than typical basalt-hosted hydrothermal systems and, instead, closely resembles those of high-temperature ultramafic-influenced vents at slow-spreading ridges. We hypothesize that deep-penetrating fluid circulation may have sustained the prolonged venting evident at the Aurora hydrothermal field with a hydrothermal convection cell that can access ultramafic lithologies underlying anomalously thin ocean crust at this ultraslow spreading ridge setting. Our findings have implications for ultra-slow ridge cooling, global marine mineral distributions, and the diversity of geologic settings that can host abiotic organic synthesis - pertinent to the search for life beyond EarthpublishedVersio