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- Bergman, Eva, 1959-, et al.
(författare)
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Atlantic salmon and brown trout in Lake Vänern : A proposal for a co-management system
- 2014
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Ingår i: Aquatic Ecosystem Health & Management. - : Taylor & Francis Group. - 1463-4988 .- 1539-4077. ; 17:4, s. 365-373
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Tidskriftsartikel (refereegranskat)abstract
- Co-management is of increasing interest for fisheries management. We explore possibilities for, and barriers to, developing a co-management system, using threatened populations of landlocked Atlantic Salmon and Brown Trout as examples. Good management of natural resources requires not only knowledge about the resource but also suitable tools to collect information and make decisions. In large ecosystems this can be difficult because many actors are involved, and various societal borders and traditions become barriers. Vänern is the largest lake in the EU and it holds several distinct populations of large-bodied landlocked Atlantic Salmon and Brown Trout. The lake is used for commercial, subsistence, and sport fishing as well as for other recreational activities, and in Klarälven, the largest river entering Vänern, sport fishing is popular. These salmonid populations were at critically low levels during the 1960s, but a stocking program since then has maintained the fishery, and at least one wild stock appears to be recovering since being protected in 1993. Ecosystem users all have different needs: in the lake, sport fishermen say that catches of hatchery fish have declined, and commercial fishermen have focused on other species. In the river, wild salmon may be recovering: sport fishing is popular and an ongoing project investigates the possibilities for salmon to be able to circumvent hydro-electrical plants and reach historical Norwegian spawning areas. Not only do we lack information about the salmonids’ different life stages, we also lack a suitable socio-political organization to find sustainable solutions to the different needs of diverse user groups. We argue that a co-management system that enfranchises user groups in the Vänern-Klarälven ecosystem will improve sustainable management of wild and hatchery fish.
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| 2. |
- Carlson, Andrew K., et al.
(författare)
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More than ponds amid skyscrapers : Urban fisheries as multiscalar human-natural systems
- 2022
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Ingår i: Aquatic Ecosystem Health & Management. - : Michigan State University Press. - 1463-4988 .- 1539-4077. ; 25:1, s. 49-58
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Tidskriftsartikel (refereegranskat)abstract
- Although social-ecological fisheries research is growing, comparatively little attention is paid to fisheries in urban environments. We aim to address this imbalance, because as cities expand worldwide, we expect urban fisheries to become more widespread and important in providing food/nutrition security, recreation, community well-being, and other benefits to fisheries stakeholders and urban dwellers across spatiotemporal scales. This paper contains a first analysis of the economic and sociocultural provisions, trade-offs, and dilemmas associated with urban fisheries to yield insights for sustainable management and planning of urban blue space. To address these objectives, we use the metacoupling framework, a method for assessing human-nature interactions within and across adjacent and distant fisheries systems. We use examples from multiple countries and data from the United States to illustrate how urban fisheries encompass flows of people, money, and information across multiple spatiotemporal scales and provide nutritional, recreational, social, and cultural benefits to fisheries stakeholders. Throughout the world, urban fisheries are influenced by wide-ranging human needs (e.g. food provisioning, recreation, aquatic resource education) that generate social-ecological effects within and beyond cities. Our analysis yields insights for developing holistic, metacoupling-informed management approaches that address the diverse social-ecological objectives and trade-offs involved in sustainable development of urban fisheries.
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| 3. |
- Dave, Göran, 1945, et al.
(författare)
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Aquatic ecosystems across boundaries: Significance of international agreements and cooperation
- 2014
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Ingår i: Aquatic Ecosystem Health & Management. - : Michigan State University Press. - 1463-4988 .- 1539-4077. ; 17:4, s. 437-446
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Tidskriftsartikel (refereegranskat)abstract
- Historically, international environmental agreements on shared transboundary waters have dealt with exploitation of natural resources like oil, minerals, forests, fisheries, shipping and trade. Presently the focus is on environmental issues relevant to conservation, restoration, protection, sustainability over-fishing, pollution, invasive species and climate change. Global assessment indicates a lack of international agreements between multiple users. A brief review of major conventions and agreements is offered with emphasis on the Great Lakes Water Quality Agreement on the North American Great Lakes and the European Water Framework Directive, since they appear to be ecologically sound and predominantly ecosystem-based. This article exemplifies the history behind these agreements with examples of environmental threats and consequences (eutrophication, pollution, invasive species and loss of biodiversity). It is concluded that such ecosystem-based agreements are essential for all large aquatic ecosystems shared by multiple users or countries for holistic and integrated management of aquatic resources.
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| 4. |
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| 5. |
- 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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| 9. |
- Dave, Göran, 1945, et al.
(författare)
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The contribution of cobalt and manganese to the acute and chronic toxicity of sediments from Lake Molnbyggen and adjacent lakes around Leksand, Sweden.
- 2004
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Ingår i: Aquatic Ecosystem Health and Management. - : Michigan State University Press. - 1463-4988 .- 1539-4077. ; 7:3
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Tidskriftsartikel (refereegranskat)abstract
- A number of studies of pollutants and their effects on the fish fauna of Lake Molnbyggen outside Leksand, Sweden have been focused on leachate from the municipal landfill (Lindbodarna), which is located above the lake. The aim of the present study was to test the toxicity of sediment from Molnbyggen and some adjacent lakes, in order to see if this could explain the causes of the effects on the fish. The sampling sites were selected in co-operation with the project group at the Swedish Environmental Protection Agency to make the results more easily comparable with those from other studies on the fish fauna in the area. Both acute and chronic tests were made with the crustacean Ceriodaphnia dubia, and the sediment samples were equilibrated with standard reference water prior to exposure. The exposures were made under standard conditions in the laboratory to make them more readily comparable between the sampling locations and with previous studies. The effects on survival and reproduction were monitored during 8 days. After that a series of Toxicity Identification Evaluation manipulations of the tested waters were made in order to identify the cause(s) of the toxicity. The results from the Toxicity Identification Evaluation tests pointed towards heavy metals as the cause of toxicity, and the analytical results of heavy metals in the water phase showed that the concentrations of six metals (Cd, Co, Mn, Ni, Pb and Zn) were significantly correlated with toxicity. The concentrations of these metals were also correlated with each other making it hard to separate cause and effect among the metals. However, the concentrations of Cd, Ni, Pb and Zn were below the expected effect concentrations, but the measured concentrations of Co and Mn were high enough to be probable causes of the observed experimental toxicity. There was no indication that lipophilic compounds should have caused these effects. Therefore, the result of this study was rather surprising, showing that heavy metals like cobalt and/or manganese which are not generally considered as environmentally problematic may be of environmental concern. Potential effects of cobalt and manganese could be mediated through the olfactory system, because both these metals have been observed to affect this system in fish. However, the link between such effects and those observed on reproduction in Lake Molnbyggen is vague.
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| 10. |
- 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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