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Riverine Plastic Monitoring during the Rainy Season in the Citarum Estuary of Muara Gembong
Get PDFThe restoration effort to clean up the river, known as "Citarum Harum" requires monitoring to estimate both the composition and the volumes of plastic pollution. The objective of the monitoring is to obtain a scientific baseline of marine plastics from Citarum River as a function of other influencing aspects. A static net trawl (60 m x 10 m, mesh size 2.5 cm, and about 1 meter submerged) was installed under the New Muara Gembong Bridge for eight consecutive days in March and April 2021 or during the rainy season. The trapped debris was collected manually into boxes using two boats and simple tools. After the drying, weighting, classification processes and by excluding natural organics (leaves/branches), plastics contributed as the most dominant for both abundance (83%) and weight (31%) followed by textiles, hazardous materials, construction materials and rubbers. The hydrological conditions as well as the tides were also observed to be one of dominant parameters. The quantification of macro-plastic litter transport from River Citarum into the Java Sea is also an aim for the ASEANO project (ASEAN – Norway cooperation project on local capacity building for reducing plastic pollution in the ASEAN region).publishedVersio
Storskala utprøving av klordosering i Driva 2021
Get PDFProsjektleder Anders Gjørwad HagenLakseparasitten Gyrodactylus salaris er ansett som en stor trussel mot norsk villaks, og myndighetene har som mål å utrydde den fra alle områder hvor den er etablert (Anon 2014). Nåværende smittestatus, i tillegg til faren for fremtidige nye innførsler fra smittede regioner og/eller infiserte vassdrag i våre naboland, tilsier at vedlikehold og utvikling av metoder for bekjempelse fortsatt er viktig. Det har derfor i en årrekke vært jobbet med å utvikle klormetoden til et fullverdig verktøy for bekjempelse av G. salaris. Gjennomføringen av forsøket i 2021 ble svært ulikt de foregående år, siden det ble store vannføringsendringer og krevende forhold. Dette har vært en fordel for metodeutviklingen, siden slike forhold fremprovoserte en del feilsituasjoner som det er svært nyttig å få luket vekk før en eventuell utryddelsesbehandling i Driva i 2022. Hoveddoseringsanleggene fungerte svært godt og etter hensikt, men vil likevel få noen få forbedringer. Sidebekkanleggene i dette forsøket viste at designet var godt og i de fleste tilfeller velfungerende. Driftssikkerheten ble likevel for mye redusert når det ble store vannføringsendringer i sidebekkene, og designendringer vil blir gjort for å avhjelpe dette. Overordnet logistikk med tanke på kjemikalier og utstyr fungerte bra, men det ble også tydelig at det ved dette omfanget er nødvendig med dedikerte team som holder orden på kjemikaliebehovet ved de ulike stasjonene. Forsøket var totalt sett vellykket, og særlig vellykket gitt de værmessige forutsetningene forsøket ble gjennomført under. Dette gir grunn til å forvente at et fullskala tiltak med klormetoden i Driva vil være gjennomførbart og med god sannsynlighet for å lykkes.publishedVersio
COASTAL HABITAT MAPPING WITH UAV MULTI-SENSOR DATA: AN EXPERIMENT AMONG DCNN-BASED APPROACHES
Get PDFWith recent abundant availability of high resolution multi-sensor UAV data and rapid development of deep learning models, efficient automatic mapping using deep neural network is becoming a common approach. However, with the ever-expanding inventories of both data and deep neural network models, it can be confusing to know how to choose. Most models expect input as conventional RGB format, but that can be extended to incorporate multi-sensor data. In this study, we re-implement and modify three deep neural network models of various complexities, namely UNET, DeepLabv3+ and Dense Dilated Convolutions Merging Network to use both RGB and near infrared (NIR) data from a multi-sensor UAV dataset over a Norwegian coastal area. The dataset has been carefully annotated by marine experts for coastal habitats. We find that the NIR channel increases UNET performance significantly but has mixed effects on DeepLabv3+ and DDCM. The latter two are capable of achieving best performance with RGB-only. The class-wise evaluation shows that the NIR channel greatly increases the performance in UNET for green, red algae, vegetation and rock. However, the purpose of the study is not to merely compare the models or to achieve the best performance, but to gain more insights on the compatibility between various models and data types. And as there is an ongoing effort in acquiring and annotating more data, we aim to include them in the coming year.publishedVersio
Driftskontroll av kalkdoseringsanlegg i Arendalsvassdraget År 2021
Get PDFProsjektleder/Hovedforfatter Rolf HøgbergetDriftskontroll av kalkdoseringsanlegg i Arendalsvassdraget gjennomføres for å avdekke effektiviteten til anleggene. Denne statusrapporten gir en dokumentasjon på driften i rapporteringsperioden (2021) og inneholder samtidig en fortegnelse over hendelser og avvik som kan danne grunnlag for forbedringstiltak knyttet til driftsrutiner, installasjoner eller kalkingsstrategi.
Bøylefoss kalkdoseringsanlegg hadde fem avvik fra pH-målet hvorav minst et kan ha hatt negativ betydning for smoltkvaliteten. Likevel betegnes driftssikkerheten som god. Kalkforbruket var 2/3 av forbruket i 2020, hovedsakelig på grunn av lavere avrenning i 2021. Ved Gauperå doseringsanlegg i Songeelva kom kalkingen tregt i gang ved flomsituasjoner, og utstrakt bruk av fast doseringshastighet gav svært varierende doser. Det var mange avvik fra pH-målet. Et stort avvik kan ha påvirket smoltkvaliteten negativt. Driftssikkerheten var ikke god. Omplassering av pH-stasjonen nedstrøms anlegget og/eller endring av styringsprinsipp kan endre forholdene. Tiltak for bedring av pH-målingene oppstrøms anlegget må også gjennomføres dersom disse skal benyttes som styringsparameter. Vanntemperaturen bør innføres som logget parameter i Songeelva.publishedVersio
Global marine litter research 2015–2020: Geographical and methodological trends
Get PDFA systematic review of research on marine macrolitter densities in the past five years (2015–2020) revealed considerable knowledge gaps in the field. Nearly half he reviewed studies were on stranded litter. Data are scarce from many of the regions estimated to mismanage the largest amounts of plastic waste. In regions where data are available these are typically from coastal areas with few data from the high and deep seas; 57% and 87% of studies on pelagic and seafloor litter, respectively, took place within 100 km from shore. Data on pelagic litter are generally constrained to the sea surface and only two of 30 pelagic studies have measured macrolitter deeper in the water column. Reported litter densities are generally highest for stranded litter, although seafloor litter densities by weight are high in some areas. Reported densities of floating litter are several orders of magnitude lower. However, a lack of standardisation of methods makes it difficult both to assess and to compare litter densities within and across the different environmental compartments in time and space. The review illustrates a great need for survey design development within the field of macroplastics and point to some long-established considerations from ecological research pertaining to independence of data points, spatial autocorrelation, sampling scale, and plot size and shape which are highly relevant also for marine litter research. These considerations are relevant both for global standardisation efforts and for independent studies. Furthermore, the knowledge gaps created by geographic and compartment biases in research needs to be addressed to identify further research needs, validate models and inform policy.publishedVersio
Naive Bayes classification model for isotopologue detection in LC-HRMS data
Get PDFIsotopologue identification or removal is a necessary step to reduce the number of features that need to be identified in samples analyzed with non-targeted analysis. Currently available approaches rely on either predicted isotopic patterns or an arbitrary mass tolerance, requiring information on the molecular formula or instrumental error, respectively. Therefore, a Naive Bayes isotopologue classification model was developed that does not depend on any thresholds or molecular formula information. This classification model uses the elemental mass defects of six elemental ratios and successfully identified isotopologues for both theoretical isotopic patterns and wastewater influent samples, outperforming one of the most commonly used approaches (i.e., 1.0033 Da mass difference method - CAMERA). For the theoretical isotopologues, the classification model outperformed an “in-house” mass difference method with a true positive rate (TPr) of 99.0% and false positive rate (FPr) of 1.8% compared to a TPr of 16.2% and an FPr of 0.02%, assuming no error. As for the wastewater influent samples, the classification model, with a TPr of 99.8% and false detection rate (FDr) of 0.5%, again performed better than the mass difference method, with a TPr of 96.3% and FDr of 4.8%. Therefore, it can be concluded that the classification model can be used for isotopologue identification, requiring no thresholds or information on the molecular formula.publishedVersio
Unravelling reasons for variability in the OECD 306 marine biodegradation test
Get PDFThe recommended test for assessing if a chemical can be biodegraded in the marine environment is performed according to the Organisation for Economic Cooperation and Development Marine biodegradation test guideline (OECD 306). However, this test is known to generate highly variable test results when comparing interlaboratory test results for the same compound. One reason can be the relatively low bacterial content compared to the inoculum used for OECD readily biodegradation tests (OECD 301). Some of the variability in data obtained from OECD 306 tests can also be due to the flexibility on how to store the seawater inoculum before starting a test. Another variable in the seawater inoculum is the source of seawater used by different laboratories, i.e., geographical location and anthropogenic activities at the source. In this study, the effect of aging seawater and the source of seawater (sample time and depth) were investigated to determine differences in the biodegradation of the reference compound aniline. Aging the seawater before starting the test is recommended in OECD 306 to reduce the background levels of organic carbon in the water. However, it also functions to acclimatize the bacterial community from the environmental source temperature to the test temperature (normally 20 °C). Herein, the microbial community was monitored using flowcytometer during the aging process. As expected, the microbial community changed over time. In one experiment, aging significantly improved the biodegradation of aniline, while in two experiments, there was no significant difference in biodegradation. Interestingly however, there was significant variability in the biodegradation of aniline between sampling seasons and depths, even when all experiments were performed in the same lab, by the same operator and seawater obtained from the same source. This highlights the need for a more robust and consistent microbial inoculum source to reduce variability in seawater biodegradation tests.publishedVersio
Tiltaksorientert overvåking av larvikittbruddene i Larvik kommune i 2021
Get PDFProsjektleder Jonas PerssonI 2021 ble bunndyr i utvalgte bekker fra steinbruddene i områdene Tvedalen og Tjølling prøvetatt. Stasjonene er plassert slik at de skal kunne måle påvirkninger fra bruddene. Referansestasjoner, som er lite eller upåvirket av avrenning fra bruddene, er også inkludert. Resultatene tyder på at bruddet Klåstad ikke har en tydelig påvirkning på bunndyrene ved stasjonen undersøkt i 2021 (KLÅ4). Bruddene Tvedalen mot Askedalsbekken, Saga Pearl og Håkestad viser derimot påvirkning i 2021 (lavere PSI-verdier enn ved referansestasjonene). Påvirkningen fra Tvedalen mot Askedalsbekken har blitt mindre etter at etablering av sedimentasjonsdam har redusert utslippene av partikulært stoff. Bedringen er mer stabil ved stasjonen ASK_opp, men det er fortsatt stor variasjon i tilstand ved ASK som ligger lengre nedstrøms i et mer roligflytende parti av bekken. Ved stasjonen fra bruddet Håkestad var det i 2020 og 2021 en betydelig større påvirkning av finsediment enn de tidligere årene.publishedVersio
New insights into submarine tailing disposal for a reduced environmental footprint: Lessons learnt from Norwegian fjords
Get PDFSubmarine tailing disposal (STD) in fjords from land-based mines is common practice in Norway and takes place in other regions worldwide. We synthesize the results of a multidisciplinary programme on environmental impacts of STDs in Norwegian fjords, providing new knowledge that can be applied to assess and mitigate impact of tailing disposal globally, both for submarine and deep-sea activities. Detailed geological seafloor mapping provided data on natural sedimentation to monitor depositional processes on the seafloor. Modelling and analytical techniques were used to assess the behaviour of tailing particles and process-chemicals in the environment, providing novel tools for monitoring. Toxicity tests showed biological impacts on test species due to particulate and chemical exposure. Hypersedimentation mesocosm and field experiments showed a varying response on the benthos, allowing to determine the transition zone in the STD impact area. Recolonisation studies indicate that full community recovery and normalisation of metal leakage rates may take several decades due to bioturbation and slow burial of sulfidic tailings. The results are synthesised to provide guidelines for the development of best available techniques for STDs.publishedVersio
Opportunities for seasonal forecasting to support water management outside the tropics
Get PDFAdvance warning of seasonal conditions has the potential to assist water management in planning and risk mitigation, with large potential social, economic, and ecological benefits. In this study, we explore the value of seasonal forecasting for decision-making at five case study sites located in extratropical regions. The forecasting tools used integrate seasonal climate model forecasts with freshwater impact models of catchment hydrology, lake conditions (temperature, water level, chemistry, and ecology), and fish migration timing and were co-developed together with water managers. To explore the decision-making value of forecasts, we carried out a qualitative assessment of (1) how useful forecasts would have been for a problematic past season and (2) the relevance of any windows of opportunity (seasons and variables where forecasts are thought to perform well) for management. Overall, water managers were optimistic about the potential for improved decision-making and identified actions that could be taken based on forecasts. However, there was often a mismatch between those variables that could best be predicted and those which would be most useful for management. Reductions in forecast uncertainty and a need to develop practical, hands-on experience were identified as key requirements before forecasts would be used in operational decision-making. Seasonal climate forecasts provided little added value to freshwater forecasts in these extratropical study sites, and we discuss the conditions under which seasonal climate forecasts with only limited skill are most likely to be worth incorporating into freshwater forecasting workflows.publishedVersio