| 11. |
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| 12. |
- Chen, Deliang, 1961, et al.
(författare)
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Attenuation of biologically effective UV doses under overcast skies: a case study from the eastern Atlantic sector of the Southern Ocean
- 2004
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Ingår i: Deep-Sea Research Part Ii-Topical Studies in Oceanography. - : Elsevier BV. - 0967-0645. ; 51:22-24, s. 2673-2682
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Tidskriftsartikel (refereegranskat)abstract
- This study deals attenuation of ultraviolet solar radiation measured during the SWEDARP 1997/1998 expedition in the eastern Atlantic sector of the Southern Ocean. Experimental data were measured on board a ship and theoretical computation of radiative transfer has been applied. Focus has been placed on biologically effective UV-B doses using three commonly applied biological weighting functions based on: inhibition of carbon dioxide fixation (Science 258 (1992) 646); Generalized plant effects (Stratospheric Ozone Reduction, Solar Ultraviolet Radiation and Plant Life 1986, Springer, Berlin) and DNA lesions (Proc. Nat. Acad. Sci. USA 71 (1974) 3363). The ratio of measured dose to that under clear sky condition, calculated by a model, was defined as transmittance which was studied in relation to other information. Further, the interrelationship between the biologically effective UV doses and various broadband irradiance in the UV-A, UV-B and PAR was established. It shows that the UV-B doses based on the three weighting functions are closely linked to each other and their cloud transmittances are nearly the same. The biologically effective UV-B doses can be estimated with reasonable accuracy from the broadband irradiance in the UV-A, UV-B and PAR regions, with UV-B giving the best results. Univariate analysis between the transmittance and zenith angle, total cloud cover and cloud base height was performed. It is found that attenuation is almost independent of zenith angle. Transmission is reduced by 7.7% if the cloud cover is increased by one octa. The average transmittance of the UV-B doses is 0.40, indicating that clouds have played an important role in reducing the UV radiation. (C) 2004 Elsevier Ltd. All rights reserved.
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| 13. |
- Dave, Göran, 1945, et al.
(författare)
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Ecosystem health of Lake Vanern: Past, present and future research
- 2015
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Ingår i: Aquatic Ecosystem Health & Management. - : Michigan State University Press. - 1463-4988 .- 1539-4077. ; 18:2, s. 205-211
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Tidskriftsartikel (refereegranskat)abstract
- The large lakes of Sweden (Vanern, Vattern, Malaren and Hjalmaren) have been monitored for more than four decades for water quality conditions to assess the impact of eutrophication from anthropogenic activities. Lake Vanern is basically an oligotrophic lake that showed signs of eutrophication, notably the emergence of algal blooms in the coastal areas (1967-1968). The lake was also contaminated, due to the discharge of pulp and paper effluents including metals such as mercury. However, ecosystem-based information is lacking for Lake Vanern. Consequently a symposium was organized in 2012 by the University of Gothenburg, Motesplats Vanersborg and the Aquatic Ecosystem Health and Management Society to: assess the current status of the health of Lake Vanern's ecosystem, identify knowledge gaps and develop a road map for the future. In this regard, Lake Vanern was compared with the North American Great Lakes to learn from their extensive, long-term data sets. A special issue devoted to the State of Lake Vanern Ecosystem symposium was published in Aquatic Ecosystem Health and Management (AEHM, Vol. 17, no. 4) including keynotes and contributed papers. The conclusions shown in the appendix (available in the online supplementary information) summarize the authors' contributions. Most of the articles covered Lake Vanern, but some were directed towards monitoring and management of Great Lakes in general, and others addressed co-operation under the auspices of international agreements and directives. Based on the background information provided by the State of Lake Vanern Ecosystem symposium and its publication in the special issue, the conveners decided that a synthesis of the symposium with recommendations for the future would be useful in boosting ecosystem research in Lake Vanern.
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| 14. |
- Drotz, Marcus, 1968, et al.
(författare)
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Forskning och kunskapsproducenter runt Vänern. Kunskapsunderlag inom Vänersamarbetet
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Rapporten är en kunskaps- och forskningsinventering av befintlig och avslutad forskning, samt kunskapsproducenter med anknytning till Vänern. Geografiskt har inventeringen begränsats till kommunerna i anslutning till Vänern samt vattnet och dess tillflöden, utflöde och kanaler. Ämnesmässigt har inventeringen fokuserat på forskning och kunskapsproduktion som direkt rör Vänerområdet inom såväl natruvetenskap, samhällsvetenskap som humaniora, speciellt det som rör arbetet inom Vänersamarbetet som är relaterat till hållbar utveckling socialt, ekonomiskt och ekologiskt. Tidsmässigt har arbetet fokuserats på att sammanställa projekt som pågår eller är avslutade under de senaste fem åren. Genom denna avgränsning har vi i mindre utsträckning tagit med forskning, kunskapsproduktion, nätverk och myndighetsdokumentation som rör större regionala områden eller Sverige i stort. Målgruppen är forskare, tjänstemän och beslutsfattare inom den offentliga sektorn. Projektet har genomförts i samarbete med Västra Götalandsregionen och Region Värmland. Till rapporten hör en referenssamling i form av en bilaga, ISBN: 91-88048-18-7.
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| 15. |
- Drotz, M.K., et al.
(författare)
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Lake Vänern: A historical outline
- 2014
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Ingår i: Aquatic Ecosystem Health and Management. - : Michigan State University Press. - 1463-4988 .- 1539-4077. ; 17:4, s. 323-330
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Tidskriftsartikel (refereegranskat)abstract
- © 2014, Copyright © AEHMS. Although Lake Vänern is the largest freshwater reservoir in Western Europe, it remains relatively unknown to the scientific community outside of Scandinavia. Therefore, we aim to give a brief outline of the lake and its geological history, in particular the landscape transformation, resource utilization, pollution history, and environmental development of the region. The landscape around Lake Vänern was shaped into its present form during the latest glaciations some 10,000years ago. Large variation exists in its tributaries, with forest in the north and agricultural areas in the south. Human influence on the landscape was relatively small until the mid-18th century. Later, in the mid-19th century, the agriculture, forestry and shipping industries underwent large transformations as the towns around the lake grew and the economy changed. Development of fishing equipment, processes and changes in catching methods industrialized the fishing industry after mid-20th century. In the 1960s the lake was considered to be one of the most heavily mercury-polluted lakes in the world. After the passing of the first national environmental protection law in Sweden the lake turned into a success story: It has been declared to be healthy. However, old pollution still affects the fishing industry. With this new focus on the environment, the scientific community started to be interested in the lake. The lake has also played a very important role as the largest hydropower reservoir in Sweden. Here, too, the environmental question is in focus and the effects of the water regulation are still under debate. The result has been loss of biodiversity and an increased risk of an inflow of invasive species from international shipping. However, still many questions remain to be answered regarding the lake and effect of ongoing climate change on the sustainable development of the lake region.
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| 16. |
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| 17. |
- Hader, D. P., et al.
(författare)
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Effects of UV radiation on aquatic ecosystems and interactions with other environmental factors
- 2015
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Ingår i: Photochemical & Photobiological Sciences. - : Springer Science and Business Media LLC. - 1474-905X .- 1474-9092. ; 14:1, s. 108-126
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Tidskriftsartikel (refereegranskat)abstract
- Interactions between climate change and UV radiation are having strong effects on aquatic ecosystems due to feedback between temperature, UV radiation, and greenhouse gas concentration. Higher air temperatures and incoming solar radiation are increasing the surface water temperatures of lakes and oceans, with many large lakes warming at twice the rate of regional air temperatures. Warmer oceans are changing habitats and the species composition of many marine ecosystems. For some, such as corals, the temperatures may become too high. Temperature differences between surface and deep waters are becoming greater. This increase in thermal stratification makes the surface layers shallower and leads to stronger barriers to upward mixing of nutrients necessary for photosynthesis. This also results in exposure to higher levels of UV radiation of surface-dwelling organisms. In polar and alpine regions decreases in the duration and amount of snow and ice cover on lakes and oceans are also increasing exposure to UV radiation. In contrast, in lakes and coastal oceans the concentration and colour of UV-absorbing dissolved organic matter (DOM) from terrestrial ecosystems is increasing with greater runoff from higher precipitation and more frequent extreme storms. DOM thus creates a refuge from UV radiation that can enable UV-sensitive species to become established. At the same time, decreased UV radiation in such surface waters reduces the capacity of solar UV radiation to inactivate viruses and other pathogens and parasites, and increases the difficulty and price of purifying drinking water for municipal supplies. Solar UV radiation breaks down the DOM, making it more available for microbial processing, resulting in the release of greenhouse gases into the atmosphere. In addition to screening solar irradiance, DOM, when sunlit in surface water, can lead to the formation of reactive oxygen species (ROS). Increases in carbon dioxide are in turn acidifying the oceans and inhibiting the ability of many marine organisms to form UV-absorbing exoskeletons. Many aquatic organisms use adaptive strategies to mitigate the effects of solar UV-B radiation (280-315 nm), including vertical migration, crust formation, synthesis of UV-absorbing substances, and enzymatic and non-enzymatic quenching of ROS. Whether or not genetic adaptation to changes in the abiotic factors plays a role in mitigating stress and damage has not been determined. This assessment addresses how our knowledge of the interactive effects of UV radiation and climate change factors on aquatic ecosystems has advanced in the past four years.
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| 18. |
- Hoffmann, L. J., et al.
(författare)
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Influence of trace metal release from volcanic ash on growth of Thalassiosira pseudonana and Emiliania huxleyi
- 2012
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Ingår i: Marine Chemistry. - : Elsevier BV. - 0304-4203. ; 132-133, s. 28-33
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies demonstrate that volcanic ash has the potential to increase phytoplankton biomass in the open ocean. However, besides fertilizing trace metals such as Fe, volcanic ash contains a variety of potentially toxic metals such as Cd, Cu, Pb, and Zn. Especially in coastal regions closer to the volcanic eruption, where ash depositions can be very high, toxic effects are possible. Here we present the first results from laboratory experiments, showing that trace metal release from different volcanic ashes can have both fertilizing and toxic effects on marine phytoplankton in natural coastal seawater. The diatom Thalassiosira pseudonana generally showed higher growth rates in seawater that was in short contact with volcanic ash compared to the controls without ash addition. In contrast to that, the addition of volcanic ash had either no effect or significantly decreased the growth rate of the coccolithophoride Emiliania huxleyi. It was not possible to attribute the effects to single trace metals, however, our results suggest that Mn plays an important role in regulating the antagonistic and synergistic effects of the different trace metals. This study shows that volcanic ash can lead to changes in the phytoplankton species composition in the high fall-out area of the surface ocean.
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| 19. |
- Jansen, Marcel A. K., et al.
(författare)
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Environmental plastics in the context of UV radiation, climate change, and the Montreal Protocol
- 2024
-
Ingår i: Global Change Biology. - : John Wiley & Sons. - 1354-1013 .- 1365-2486. ; 30:4
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Tidskriftsartikel (refereegranskat)abstract
- There are close links between solar UV radiation, climate change, and plastic pollution. UV-driven weathering is a key process leading to the degradation of plastics in the environment but also the formation of potentially harmful plastic fragments such as micro- and nanoplastic particles. Estimates of the environmental persistence of plastic pollution, and the formation of fragments, will need to take in account plastic dispersal around the globe, as well as projected UV radiation levels and climate change factors.image
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| 20. |
- Jansen, Marcel A. K., et al.
(författare)
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Plastics in the environment in the context of UV radiation, climate change and the Montreal Protocol : UNEP Environmental Effects Assessment Panel, Update 2023
- 2024
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Ingår i: Photochemical and Photobiological Sciences. - : Springer Nature. - 1474-905X .- 1474-9092. ; 23, s. 629-650
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Tidskriftsartikel (refereegranskat)abstract
- This Assessment Update by the Environmental Effects Assessment Panel (EEAP) of the United Nations Environment Programme (UNEP) considers the interactive effects of solar UV radiation, global warming, and other weathering factors on plastics. The Assessment illustrates the significance of solar UV radiation in decreasing the durability of plastic materials, degradation of plastic debris, formation of micro- and nanoplastic particles and accompanying leaching of potential toxic compounds. Micro- and nanoplastics have been found in all ecosystems, the atmosphere, and in humans. While the potential biological risks are not yet well-established, the widespread and increasing occurrence of plastic pollution is reason for continuing research and monitoring. Plastic debris persists after its intended life in soils, water bodies and the atmosphere as well as in living organisms. To counteract accumulation of plastics in the environment, the lifetime of novel plastics or plastic alternatives should better match the functional life of products, with eventual breakdown releasing harmless substances to the environment.
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