| 1. |
- Sonesten, Lars, et al.
(författare)
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Uncertainty in nutrient loads resulting from discharge data uncertainty
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Reliable estimates of nutrient loads discharged to the sea are important for managing marine and upstream water resources. Most major river mouths in Sweden are monitored for discharge and nutrient concentrations. These data are used together with direct point source loads as the basis for annual load estimates. The estimates are used as a basis for national environmental policy and they are reported to international bodies such as the EEA (SoE TCM report), OSPAR (OSPAR RID report) and HELCOM (PLC-Annual report). The Pollution Load Compilation-Annual (PLC-Annual) report to HELCOM is used as evidence for managing eutrophication in the Baltic Sea. The reliability of load estimates based on monitoring data in gauged catchments is affected by uncertainty in the discharge and nutrient concentration data. Knowledge about the uncertainty associated with the load estimate values is of fundamental importance when using these data as a basis for management decisions, e.g. for assessing fulfillment of national environmental objectives, or analysing trends in the loads over time (i.e. is it a real change that is observed or is it a result of data uncertainty?). In the PLC-Annual reports for 2015 and onwards both the loads and the estimated uncertainty in the loads should be reported. The aim of this study was to quantify uncertainty in discharge data resulting from rating curve uncertainty and its impact on uncertainty in the nitrogen and phosphorous PLC-Annual load estimates at selected river mouths. In total there are 34 river mouth stations for which the PLC-Annual load calculations are based entirely on measured discharge (i.e. no modelled data are used). We used data from the 12 river mouth stations that are run by the Swedish Meteorological and Hydrological Institute, SMHI, for which data were available to estimate discharge uncertainty. These stations are representative of all the 34 stations in terms of catchment characteristics except for a lower degree of river regulation. Discharge was calculated indirectly from water level (stage) at all these stations using a rating curve, which is fitted to stage–discharge gaugings. For each discharge station we used 15-minute water-level data for 2005–2014 and the stage–discharge gaugings that had been used to fit the current rating curve equation. Rating curve uncertainty was estimated with the Voting Point likelihood method in a Monte Carlo analysis, essentially estimating multiple feasible rating-curve parameter sets that are compatible with the uncertain gauging data. We estimated 40,000 rating curves and the method succeeded in 5 capturing the uncertainty in the gauging data at all stations. Only a few of the stations had extrapolated rating curves during the time period and most of the stations had a well constrained rating curve uncertainty for the mid and high flow range. For each rating curve a time series of discharge was calculated from the stage time series and aggregated to daily values. The 90% uncertainty interval for the relative uncertainty in the daily flow percentiles was around ±15–50% for low flows (Q95, i.e. the flow exceeded 95% of the time), ±10% for mean flow, and around ±10–25% for high flows (Q0.1 and Q0.01). These estimates include both model and data error, which means that they are likely conservative estimates. Rating curves are normally updated continuously as new data become available. Effects of historic rating curve updates were visible in the official discharge time series for some of the stations (as differences in comparison to the PLC-Annual discharge data). These differences were of a similar magnitude as the 90% uncertainty interval from the rating-curve uncertainty estimated here. The uncertainties we estimated from the gauging data were therefore representative of those stemming from real rating-curve changes in the last 10 years. The nutrient load uncertainty was estimated by repeating the PLC-Annual load calculation method (interpolation of monthly nutrient concentrations to daily values that are then multiplied by discharge) for each estimated discharge time series. As a result of the rating curve uncertainty, the estimated relative uncertainty in the PLC-Annual nitrogen and phosphorous loads was ±7–14% (the half-widths of the 90% interval). However, there were biased uncertainty distributions up to ±30–40% for individual years as a result of errors in the water-level time series (that had been updated after the data was delivered for the load calculations). We therefore recommend that the historic load estimates are updated regularly in the future to take advantage of successive data quality improvements. The potential impact of load uncertainty should be considered when load estimates are used for other analyses or as a basis for policy decisions. We expect a greater impact on load comparisons between catchments compared to between sea basins, and for individual years compared to long-term averages. Trend analyses are expected to be obscured where the magnitude of the uncertainty is large in relation to the strength of the measured trend. This study has quantified the uncertainty arising from discharge data and has established an uncertainty estimation method that can be extended to include other components of the total load uncertainty. We recommend that future studies build on the current method to include uncertainty
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| 2. |
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| 3. |
- Sonesten, Lars, et al.
(författare)
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Vattenkvaliten i Vänerns tillflöden och utlopp
- 2016
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Ingår i: Vänern : årsskrift från Vänerns vattenvårdsförbund. ; 96, s. 50-59
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- De flesta av Vänerns tillflöden uppvisade en något högre vattenföring under året än normalt, vilket framförallt beror på att året överlag var jämförelsevis nederbördsrikt. Den något förhöjda vattenföringen innebar även att transporterna av näringsämnen i vattendrag var något förhöjda. Halterna av kväve och fosfor var överlag på normala nivåer, även om några vattendrag har uppvisat ökande halter under senare år. Halterna av organiskt material har under senare år stabiliserats eller i några fall till och med minskat efter en period med stadigt ökande halter.
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| 4. |
- Ejhed, Helene, et al.
(författare)
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Uppskattning av utsläpp för Cd, Hg, Cu ochZn på TRK-områden : Slutrapport januari 2005
- 2005
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna rapport sammanställer lokala bruttoutsläpp av diffusa källor , punktkällor samt totalt utsläpp av metallerna kadmium, koppar, kvicksilver och zink geografiskt fördelat till rapporteringsområden för att ge underlag till rapportering enligt ramdirektivet för vatten. Ingen beräkning av avskiljning av metaller till mark eller sediment under transporten genom vattensystemet har genomförts.Utsläpp av diffusa källor har beräknats baserat på inom projektet nya framtagna typhalter och samband för utlakning av metaller för olika markanvändning samt sammanställningar av kända typhalter för utlakning av typhalter där de bedömts vara trovärdiga. De nya typhalterna baseras på uppmätta halter från miljöövervakningsprogram för sjöar och vattendrag samt typområden för jordbruksmark. Deposition av metallerna på öppen sjöyta har tagits fram baserat på uppmätta depositionsvärden kopplat till nederbörd för området samt för metallerna kadmium, koppar och zink baserat på ett omfattande nätverk av uppmätta halter i husmossa och väggmossa. Typhalterna har multiplicerats markanvändning som till stor del tagits fram inom TRK-projektet förutom vägmark som tagits fram för det statliga vägnätet inom detta projekt. Typhalterna har också multiplicerats med avrinningen för området som togs fram inom TRK-projektet som ett långtidsmedel för perioden 1985-2000. Stora punktutsläpp har framför allt inhämtats från Länsstyrelsens databas EMIR med efterföljande omfattande kvalitetssäkring av data. Data har inhämtats för år 2003 eller senast registrerat data, nedlagd verksamhet exkluderad utom avseende deponier och avfallsupplag. Utöver denna databas har data inhämtats från enskilda Statistiska meddelanden avseende utsläpp från reningsverk och miljörapporter och uppgifter från Länsstyrelser och Naturvårdsverks rapporter avseende gruvverksamhet samt SMED rapport avseende avfallsanläggningar. Små punktkällor har ansatts schabloner för utsläpp baserat på resultat i enskilda referenser och SMED rapporter och avseende små reningsverk baserat på medelvärde för reningsgrad och föroreningsmängd redovisat för stora reningsverk.Resultaten redovisas i tabeller summerat per vattendistrikt och i kartbilder över utsläppen per rapporteringsområde och havsområde. Kartorna läggs till rapporten i separata filer med numrering enligt rapportens avsnitt kartbilder. Kartorna presenterar klassade data enligt percentil indelning av utsläpp i kg i 25:e, 50:e, 75:e och 90:e percentilen för att visa fördelningen av utsläppen så tydligt som möjligt samt kartor över omräknat utsläpp vid källan med hjälp av avrinning och områdets areal till mg/l med klassning enligt bedömningsgrunder för miljökvalitet, sjöar och vattendrag för att visa utsläppen i förhållande till gränser för biologisk effekt. Resultaten presenteras även för tillförseln till havsområden klassade enligt 25:e, 50:e, 75:e samt 95:e percentilen av diffusa utsläpp och totalt utsläpp i enheten g/ha för att skillnader i tillrinningsområdets areal inte skulle dominera resultatet. Tillförseln av punktkällor till havsområdena presenteras totalt summerat i kg eftersom dessa källor inte är relaterade till arealen. Jämförelser mellan beräknat resultat och beräknade transporter baserat på uppmätta halter i flodmynningarna visar att beräkningarna är av rätt storleksordning. Vissa områden har större transport baserat på uppmätta data än beräknat resultat och kan bero på brister i de ingående utsläppen eller avsaknad av utsläppskällor som till exempel återcirkulation av metaller från sediment.Osäkerheter i markläckagens storlek vilka står för en stor del av utsläppen kan också vara en orsak till skillnad i resultat och transporterad mängd i flodmynningarna. Resultaten för jordbruksmarkens utlakning av kadmium jämfördes dessutom med en beräkning av kadmiumbalansen baserat på tillförsel i form av gödsel, kalkning, utsäde, deposition samt slam och bortförsel i form av upptag i gröda till jordbruksmarken.Skillnader mellan resultat i denna rapport och tidigare totala sammanställningar av utsläpp av metaller till vatten beskrivs översiktligt i avsnittet diskussion. Brister i indata redovisas delvis i delrapporter avseende typhalter för de diffusa markläckagen i appendix till rapporten och delvis i avsnittet bristanalys. Estimerat bortfall av utsläpp för olika typer av större punktkällor på grund av saknade data har beräknats och visar att stora enskilda utsläpp troligen saknas i rapportens resultat.
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| 5. |
- Fonticella, D, et al.
(författare)
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Tilapia aquaculture in Cuba
- 2000
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Ingår i: Tilapia Aquaculture in the Americas. - : Baton Rouge: The World Aquaculture Society. ; , s. 184-203
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 6. |
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| 7. |
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| 8. |
- Fölster, Jens, et al.
(författare)
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Åtgärder ger effekt
- 2012
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Ingår i: Havet 2012. - 9789198064612 ; , s. 33-34
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 9. |
- Grimvall, Anders, et al.
(författare)
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Mitigating marine eutrophication in the presence of strong societal driving forces. Report no 2017:3 Swedish Institute for the Marine Environment
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Man-made eutrophication of lakes, coastal waters, and oceans occurs in practically all populated parts of the world, and in many regions the problem is increasing. The ecological effects of excessive input of nutrients include massive algal blooms, extensive oxygen depletion, and recurrent incidences of fish kills. The East China Sea, the Gulf of Mexico, the Bay of Bengal, and the Baltic Sea are some examples of sea basins in which nutrient over-enrichment has resulted in unnaturally large hypoxic zones, where the oxygen concentration is so low that animal life suffocates and dies. Such serious effects are negative not only for ecological reasons, but they also mean the loss of economically valuable resources. Measures to prevent or reduce fluxes of nutrients into marine waters were first undertaken in some parts of Europe and North America. Wastewater treatment plants in urban areas were upgraded to enable the efficient removal of nutrients, and discharges from industry were substantially reduced. Step by step, diffuse emissions from agriculture, transport, and other sectors were also addressed. A brief review of the measures currently in place in a number of countries showed that, despite progress in some areas, the targets of international conventions and other agreements are rarely completely achieved. One reason might be that the flow of nutrients through society and into coastal waters is strongly intertwined with basic human needs, especially the production and consumption of food. Another reason might be that all relevant actors do not participate in the mitigation efforts. In addition, the impact of global social and economic trends is rarely addressed by the authorities who are developing programs of measures (POMs). This report elucidates how politicians, numerous decision-makers in both authorities and enterprises, and conscious consumers can help to reduce eutrophication of coastal waters and oceans. This is done by first reviewing the current measures and instruments in place to mitigate marine eutrophication. Thereafter, it is explored how the range of intervention options can be expanded by systematically linking the flows of substances and goods to the relevant actors and by assessing these actors’ potential to influence nutrient fluxes. Selected global trends and innovative technologies of relevance are also considered. Moreover, the need and benefit of simultaneously working toward different sustainable development goals is addressed. Current measures in selected countries. Sweden, which is one of the nine Baltic Sea countries, has developed a very complex mix of physical measures and policy instruments to combat marine eutrophication. Efficient wastewater treatment has been accomplished by simultaneously paying attention to institutions, legislation, and financing of measures. Leakage of nutrients from agriculture has been reduced by combining legislation and ordinances from the Government and national agencies with inspections and guidance from county administrative boards and municipalities. Voluntary actions by farmers are to some extent subsidized. Emissions from shipping, especially nitrogen emissions from fuel combustion, are another major source of marine eutrophication, and national regulations have been decided upon and implemented. Collaboration with other countries is needed to achieve unified actions, but such actions take time. Denmark, which is another Baltic Sea nation, produces large amounts of pig meat, and this has made it necessary to address the leakage of nutrients from agriculture. Originally, nitrate pollution of inland waters and groundwater was in focus, but measures to protect such waters have also resulted in the improved status of marine waters. Politically, Denmark has met the challenges by employing two different abatement strategies. Detailed regulation of agricultural practices using almost identical rules in the whole of Denmark is now being replaced by spatially differentiated regulation. The Netherlands by the North Sea is another country with large-scale and intensive animal farming. Because livestock production generates considerably more manure than is required by agriculture in the immediate vicinity, the cycling of nutrients is disrupted. To reduce regional imbalances in nutrient fluxes, Dutch farmers are now required to have a certain percentage of their surplus manure treated for sale outside the Dutch fertilizer market. In the US, POMs have long had a strong focus on point-source emissions, including emissions from concentrated animal feeding operations. Extensive outreach activities, voluntary actions, and strong ambitions to involve a wide range of stakeholders characterize several of the POMs. However, the overall progress to reduce fundamental imbalances in nutrient fluxes in food production has been slow. India and Bangladesh, which border the Bay of Bengal, are two countries with a rapidly increasing population and rapid urbanization. Urban sanitation and wastewater treatment for the large cities are in focus, but without upgrading the treatment systems so that they include efficient removal of nutrients, there is a substantial risk of increased eutrophication problems. China has changed faster than any other large country over the past few decades. New environmental laws and substantial investments in wastewater treatment plants indicate an increased willingness to address water pollution, including marine eutrophication. However, implementation of new environmental standards is lagging behind changes in nutrient fluxes. The impact of urbanization, transitions in agriculture, and dietary shifts are so strong that fundamental imbalances in nutrient fluxes are likely to persist for a long time. Generally, abatement of eutrophication problems starts with efforts to eliminate hot spots of nutrient pollution by regulating point-source emissions and agricultural practices. Addressing eutrophication by considering large-scale imbalances in nutrient fluxes and desirable transitions in society usually comes later. Increased cooperation within sea conventions, stronger involvement of major enterprises, and coordinated efforts to simultaneously achieve several sustainable development goals represent a way forward. Cooperation within international sea conventions and watershed task forces In Europe, the contracting partners of the HELCOM and OSPAR conventions are cooperating to reduce eutrophication in the Baltic Sea and the Northeast Atlantic, respectively. Such regional sea conventions are important platforms for mutual decisions between the member states. They also form bodies large enough to push forward issues in global organizations such as the International Maritime Organization. The European Union broadens the cooperation possibilities by offering more partners and by providing unified legislation and financial support. India and Bangladesh participated in the Bay of Bengal Large Marine Ecosystem project as a way to share visions and objectives and to engage in discussion concerning the measures to be implemented. This project ended in 2015, and future work related to the project is currently being discussed. In the US and China, the Mississippi and Yangtze river basins are so large that watershed task forces play a key role in abatement programs. Expansion of intervention options The human pressure on many coastal and offshore water bodies remains unacceptably high even though several measures have already been implemented. This indicates that there is a need to expand the range of intervention options. Systems analysis of fluxes of nutrients through society can reveal a multitude of activities and behavioral patterns of institutions, organizations, and individuals that affect the pressure on marine environments. When developing policy instruments and measures to reduce the pressure on marine environments, it is important to identify actors who have the potential to change their behaviors. By analyzing product chains, it is often possible to identify such actors or groups of actors. A case study of the product chain for meat produced and consumed in Sweden revealed that although the number of activities in the chain is large, the actual number of influential actors is rather small. This study also showed that it is not only the actors who actually release nutrients into the sea who can influence the nutrient loads. Large food retailers, for example, can influence what is consumed and thereby also the fluxes of nutrients along the entire chain from production of animal feed and food to emissions from sewage systems. Chefs with a media presence, NGOs, and conscious consumers are other examples of key actors. Taking stock of the current measures as well as our general procedure for linking key actors to fluxes of substances and products, we propose new measures to mitigate the eutrophication of marine waters. In contrast to many of the current measures that can be characterized as endof- pipe solutions or cleanup operations, these new measures have the potential to transform society into becoming more ecologically, economically, and socially sustainable. The proposed measures all relate to dietary issues or to better recycling of nutrients. Three proposed measures A. Protein consumption adjusted to health requirements. People in many countries have increased their average protein consumption to levels far higher than needed. Phosphorus and nitrogen fluxes through society and from society to nature increase with increased protein consumption. Taking Sweden as an example, a 20% lower production and consumption of protein could substantially lower the nutrient input into the Baltic Sea without increasing the risk of protein deficiency. Such dietary changes are in the hands of many actors such as legislators, agencies, market actors, and NGOs. B. Increased aquaculture with minimal loss of nutrients. Aquaculture has considerable potential to e
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| 10. |
- Quintana, Isabel, et al.
(författare)
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Vänern - Växtplankton
- 2011
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Ingår i: Rapport - Vänerns vattenvårdsförbund. - 1403-6134. ; , s. 35-38
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Annan publikation (övrigt vetenskapligt/konstnärligt)
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