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Intercomparison 2438: pH, Conductivity, Alkalinity, NO3-N, Cl, SO4, Ca, Mg, Na, K, TOC, Tot-P, Tot-N, Al, Fe, Mn, Cd, Pb, Cu, Ni, and Zn
Get PDFProsjektleder: Tina BryntesenTwenty-one laboratories from fifteen countries accepted the invitation to join the ICP Waters chemical intercomparison. Two sets of samples were prepared and distributed to the participants: one for the determination of ions and one for metals. This year, acceptance rates were based on the Z’-scores obtained by the participants. In general, acceptance rates were high for all parameters. General trends in the choice of techniques continue to shift towards plasma from atomic absorption, and to mass detection from ionic emission. This is especially promising for the determination of metals at low levelsNorwegian Ministry of Climate and Environment United Nations Economic Commission for Europe (UNECE)publishedVersio
Low to moderate wave exposure did not impact blue mussel (Mytilus edulis) growth in a mesocosm study.
Get PDFLittle is known about the causes of the decline in blue mussel populations in the North Atlantic. If mussel beds are to be protected, and maybe even restored, we need knowledge about environmental conditions under which blue mussels can survive and grow. Wave exposure impacts the growth and abundance of blue mussels by impacting food availability, predation, competition and sedimentation. In the field it is difficult to separate the effects of the different variables, and we therefore wanted to perform a simple, but controlled, mesocosm study on the impact of wave exposure on blue mussel (Mytilus edulis) growth. We placed three replicate blue mussels in each of 12 mesocosm basins, of which six had high and six had low wave level. Each of the 36 blue mussels were measured weekly for 13 summer weeks and the measured parameters (length, width, thickness, weight and displacement volume) were analysed against wave exposure and time using a non-parametric Generalised Additive Model (GAM). Surprisingly, we found no effect of wave exposure on any of the parameters. This could be because wave exposure is not as important as we have believed, but that it usually captures other factors, such as sedimentation, predation and competition. It could also be explained by the level and span in wave exposure being too low, failing to generate measurable effects. Our advice for future studies is to increase the difference in wave exposure levels, but still perform controlled studies to separate the effect of wave exposure from other variables.publishedVersio
Benthic diatom community response to the sudden rewetting of a coastal peatland
Get PDFThe coastline of the shallow southern Baltic Sea is a highly dynamic system of spits, lagoonal systems and subtidal flats. On the land side, coastal peatlands are common. Intact peatlands provide important ecosystem services, however, many peatlands have been severely degraded due to human activities. Many coastal peatlands are also separated from the Baltic Sea by artificial dunes or dykes in order to facilitate drainage and coastal protection measures. Due to their potential to act as carbon sinks, as well as buffer zones against sea level rise and flooding events, there is an increasing interest in the restoration and rewetting of coastal peatlands. Microphytobenthic communities are important primary producers in coastal systems and peatlands and diatoms are often the dominant microphytobenthic group in temperate regions. In November 2019, the removal of the dyke that separated the Polder Drammendorf (a drained, oligohaline peatland), from the adjacent Baltic Sea lagoon Kubitzer Bodden represented a unique chance to study the sudden rewetting of a degraded coastal peatland with brackish water and its effect on the microphytobenthos. The aims of this study were to investigate the poorly known diatom community composition of coastal peatlands, to determine the effects of flooding events on diatom composition and biomass in coastal peatlands as well as the effects of nutrient and substance release from the peatlands on the diatom communities of adjacent coastal waters. We investigated and documented the impact of this sudden rewetting on the benthic diatom communities of the peatland and the adjacent lagoon over the course of one year, applying the latest taxonomy and measuring key environmental factors. The results deepen the understanding of diatom community composition, taxonomy and ecology and explore the influence of land-sea exchange processes on the benthic diatoms of the Baltic Sea coast.publishedVersio
Carbon stocks in Norwegian eelgrass meadows across environmental gradients
Get PDFSeagrass meadows are well-known for their capacity to capture and store blue carbon in sediments. However carbon stocks vary significantly between meadows, spanning more than three orders of magnitude on both local and global scales. Understanding the drivers of seagrass carbon stocks could help improve strategies for incorporating blue carbon into management plans. Here, we measured sediment carbon stocks in eelgrass (Zostera marina) meadows and unvegetated areas along the Norwegian coast, spanning wide gradients in temperature, wave exposure, water depth, salinity, and eelgrass biomass. Carbon stocks were generally higher in eelgrass meadows than in adjacent unvegetated areas, yet they displayed considerable variation (400 − 30 000 g C m−2 at 50 cm sediment depth) even among nearby sites. Overall, the highest carbon stocks were found in deeper, muddier, sheltered meadows near river mouths. These sites likely have the highest input and retention of carbon from different sources. Consequently, they should be prioritized as conservation targets for preserving coastal blue carbon stocks. Despite ever-increasing efforts to quantify seagrass blue carbon globally, high uncertainties still persist, partly due to differing methodologies, processes, and environmental context. Blue carbon stock estimates could be improved through the coordination of standardised mapping and sampling methods.publishedVersio
A systematic review on the use of food web models for addressing the social and economic consequences of fisheries policies and environmental change
Get PDFFisheries are complex systems. Food web models are increasingly being used to study the ecological consequences of fisheries policies and environmental change on such systems around the world. Nonetheless, these consequences extend well into the social, economic, cultural, and political domains of such systems. The main goal of this contribution is to characterize how food web models are being used to study the socioeconomic consequences of management actions and environmental change. We conducted a systematic literature review covering research published between January 2010 and July 2023. Only 47 papers (out of an initial pool of 506 publications) met our research criteria. Based on this, it is evident that the body of literature has been increasing slowly and at a constant rate – a condition not shared with other emerging research fields. Modeled systems were mostly marine (87%), covering the waters of 38 countries across 19 Large Marine Ecosystems; albeit mostly in the Global North. The ecological components of the reviewed models (e.g., functional groups) were represented at a much finer scale than their socioeconomic counterparts. Most models were developed using Ecopath with Ecosim (68%) or Atlantis (21%) modeling software suites. Four key research foci were identified across the selected literature. These shaped the methodological approaches followed, as well as the models’ capabilities, the simulation drivers, the way food webs were integrated with bioeconomic models, and the performance metrics they used and reported. Nonetheless, less than half captured social concerns, only one-third addressed trade-offs among management objectives, and only a handful explicitly addressed uncertainty. The implications of these findings are discussed in detail with respect to resource managers needs for ecosystem-based fisheries management and ecosystem-based management. Our collective understanding of the interlinkages between the biophysical and socioeconomic components of aquatic systems is still limited. We hope this review is seen as a call for action and that the food web modeling community rises to the challenge of embracing interdisciplinarity to bridge existing knowledge silos and improve our ability to model aquatic systems across all their domains and components.publishedVersio
Plastics in biota: technological readiness level of current methodologies
Get PDFPlastics are persistent in the environment and may be ingested by organisms where they may cause physical harm or release plastic additives. Monitoring is a crucial mechanism to assess the risk of plastics to the marine and terrestrial ecosystem. Unfortunately, due to unharmonised procedures, it remains difficult to compare the results of different studies. This publication, as part of the Horizon project EUROqCHARM, aims to identify the properties of the available analytical processes and methods for the determination of plastics in biota. Based on a systematic review, reproducible analytical pipelines were examined and the technological readiness levels were assessed so that these methods may eventually (if not already) be incorporated into (harmonised) monitoring programs where biota are identified as indicators of plastic pollution.publishedVersio
Mikroplast i avløpsvann fra gjenvinningsanlegg for plast
Get PDFAvløpsvann fra to gjenvinningsanlegg for plast ble analysert for mikroplast. I begge anleggene ble mikroplast påvist, og konsentrasjonene varierte fra 7-51 partikler pr. liter og masse fra 8-316 μg pr. liter. Polypropylen og polyetylen var de dominerende plastpartiklene som ble påvist, som også utgjorde hovedpart av plastpolyme- rene som ble gjenvunnet. Tilførsler (kg/år) kunne ikke beregnes da vannforbruk ikke måles. Konsentrasjonene og massene som ble påvist var betydelig lavere enn funn i avløpsvann fra gjenvinningsbedrifter fra andre land. Sammen- ligning av målte konsentrasjoner og masser av mikroplast fra ulike studier er derimot utford- rende, da standardiserte metoder mangler, og svært ulike prøvetakningsmetoder og analyse- metoder for påvisning av mikroplast benyttes. Informasjon om innhold av mikroplast i avløps- vann fra gjenvinningsanlegg for plast er mange- lfullt i Norge og andre land, og det er behov for mer kunnskap. Ved utslipp av mikroplast bør rensetiltak vurderes, da det er store bekymrin- ger knyttet til effekter av mikroplast på vann- miljøet.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
Get PDFSudden 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
Effect of pooled sampling in the MILFERSK program
Get PDFProsjektleder: Morten JartunThe MILFERSK monitoring program is studying the occurrence and biomagnification of contaminants in freshwater ecosystems, mainly Lake Mjøsa. For the last 10 years, individual samples of muscle and liver from brown trout have been analyzed for a wide range of environmental contaminants. In this report we are statistically evaluating the effect of converting to pooled samples, i.e., 5 individuals constituting one composite sample. Main results indicate that analyzing pooled samples could mask or hide extreme concentrations, limiting the possibility to detect early occurrence in the environment. The statistical power will be weaker when studying biomagnification potential and time series, as fewer data points are included in the statistical models.MiljødirektoratetpublishedVersio
Sulphate removal by membrane filtration minimizes the risk of hydrogen sulphide formation in fixed bed biofilters
Get PDFHydrogen sulphide (H2S) is one of the suspected reasons behind sudden mass fish mortalities in recirculating aquaculture systems (RAS) in recent years. H2S production in aquaculture systems depends on sulphate and organic matter availability, presence of specific microbial groups, and local anoxic conditions. Specific potential H2S production hotspots in RAS have been identified within biofilters and in accumulated sludge. Current H2S control methods have been identified, such as improved hydrodynamics, increasing degassing efficiency, chemical addition of hydrogen peroxide or ozone, but have not been efficient or widespread applied. In this study, a nanomembrane filtration system was installed at a brackish water (mixture of seawater and freshwater to 15 ppt) smolt production site in Norway to remove sulphate ions from the seawater intake line (15 times reduction). The hydrogen sulphide production potential of the nanofiltered seawater mixed with freshwater (n = 3) was compared to an unfiltered seawater and freshwater mixture (15 ppt, n = 3) for 42 days in experimental scale biofilters using industrial fixed bed media. In both treatments, the linear production of H2S started around the time that bulk water measurements of oxidation-reduction potential (ORP) and dissolved oxygen (DO) dropped below 0 mV and 1 mg/L, respectively. As expected, the highest H2S concentration was observed in unfiltered water reactors, which also reached the highest concentration faster than filtered-water reactors. A 15 times reduction in initial sulphate levels by the nanofiltration membrane led to overall three times lower H2S production and delayed the onset of production by two days. Hence, membrane-filtering intake water decreased the risk of H2S production. A limitation in this study, however, was that sulphate was not completely removed from the intake water, and the next steps should evaluate how increasing the effort of membrane operation to completely remove sulphate affect the dynamics of H2S production in RAS.publishedVersio