| 1. |
- Bauer, Barbara, et al.
(author)
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Reducing eutrophication increases spatial extent of communities supporting commercial fisheries : a model case study
- 2018
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In: ICES Journal of Marine Science. - : Oxford University Press (OUP). - 1054-3139 .- 1095-9289. ; 75:4, s. 1306-1317
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Journal article (peer-reviewed)abstract
- In this study we investigate if eutrophication management has the potential to substantially affect which areas are going to be most suitable for commercial fishing in the future. We use a spatial ecosystem model, forced by a coupled physical-biogeochemical model, to simulate the spatial distribution of functional groups within a marine ecosystem, which depends on their respective tolerances to abiotic factors, trophic interactions, and fishing. We simulate the future long-term spatial developments of the community composition and their potential implications for fisheries under three different nutrient management scenarios and changing climate. The three nutrient management scenarios result in contrasting developments of bottom oxygen concentrations and phytoplankton abundance, with substantial effects on fish production. Nutrient load reduction increases the spatial extent of the areas suitable for the commercially most valuable demersal fish predator and all types of fisheries. This suggests that strategic planning of fishery management strategies could benefit from considering future changes in species distributions due to changes in eutrophication. We show that combining approaches from climate research, physical oceanography, biogeochemistry, biogeography, and trophic ecology with economical information provides a strong foundation to produce scientific knowledge that can support a multisectoral management of ecosystems.
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| 2. |
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| 3. |
- Hammarlund, Cecilia, et al.
(author)
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Fisheries management under nutrient influence : Cod fishery in the Western Baltic Sea
- 2018
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In: Fisheries Research. - : Elsevier BV. - 0165-7836 .- 1872-6763. ; 201, s. 109-119
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Journal article (peer-reviewed)abstract
- A fisheries management model that identifies the economic optimal management of fisheries under the influence of nutrients is presented. The model starts from the idea that growth in fish biomass increases with increasing availability of nutrients owing to higher food availability up to a peak, after which growth falls due to eutrophication. The model is applied to Swedish and Danish cod fisheries in the Western Baltic Sea and identifies the welfare contribution of the fisheries, measured as the sum of resource rent and producer surplus. In 2010, the welfare contribution was −28% of the landing value. Maximizing the model with respect to effort alone and additionally over nitrogen concentration increases the contribution to 11% of the landing value in 2010. The analysis shows that the welfare effect of reducing fishing effort through management reforms is large, but that the effect of incorporating nitrogen in fisheries policy is small.
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| 4. |
- Nielsen, Max, et al.
(author)
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Can small-scale fisheries survive market-based management? Nordic evidence
- 2022
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In: Fish and Fisheries. - : Wiley. - 1467-2960 .- 1467-2979. ; 23:1, s. 256-272
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Journal article (peer-reviewed)abstract
- Market-based fisheries management systems give incentives to reduce the fleet size and employment, which increases earnings and contributes to resolve the tragedy of the commons. However, the often-stated expectation that economies of scale cause the disappearance of small-scale fishery is not observed in many cases. In this study, we investigate the effects on fleet structure in the period after introducing individual fishing quotas or individual fishing days with various degrees of transferability in selected fisheries in the seven Nordic countries. Despite observing economies of scale in most cases, it is found that the market-based fisheries management often does not reduce the small-scale fleet more than the fleet of large vessels. This is explained partly by small vessels targeting demersal species and large vessels pelagic species, and partly by the larger need of larger than small vessels to continuously utilize their capital stocks through fast adaptation to ensure return. A more important explanation is the regulation design, with limitations in sale of fishing rights and lease between vessel groups and regions and in the share of the total quota holdings of fishing rights by individuals and vessels. This is important for countries considering the introduction of market-based fisheries management, since the Nordic experiences show that with proper regulation design, economic gains can be achieved with small-scale fishing surviving even under economies of scale.
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| 5. |
- Nielsen, Max, et al.
(author)
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The myth of the poor fisher : Evidence from the Nordic countries
- 2018
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In: Marine Policy. - : Elsevier BV. - 0308-597X. ; 93, s. 186-194
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Journal article (peer-reviewed)abstract
- Fishers are often perceived to be poor, and low income levels are used to justify subsidies and other types of direct and indirect income support to maintain coastal communities. In this study fishers’ income levels are investigated in four Nordic countries; Denmark, Iceland, Norway and Sweden for different types of fishers and vessels and in comparison to alternative occupations. The most important result is that fishers in these countries are doing relatively well, and only in Sweden is the fishers’ average income level below the average national income. Within the fleets, there are substantial differences. Owners of coastal vessels tend to have the lowest income, and also lower than crews. Owners as well as crews on larger vessels tend to do much better and in the largest fishing nations, Iceland and Norway, they do especially well.
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| 6. |
- Nielsen, Rasmus, et al.
(author)
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Fishing for nutrients – economic effects of fisheries management targeting eutrophication in the Baltic Sea
- 2019
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In: Ecological Economics. - : Elsevier BV. - 0921-8009 .- 1873-6106. ; 160, s. 156-167
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Journal article (peer-reviewed)abstract
- The Baltic Sea is one of the most eutrophied seas in the world, facing challenges with both hypoxia and algae blooms. In this study we analyse the effect of using different fishery policy instruments to reduce nutrient loads by removing fish biomass from the ecosystem. The study covers Danish, Finnish and Swedish pelagic fisheries. We distinguish between a private optimum maximising the net present value from fishing and a social optimum including the positive externality of removing nutrients. A dynamic bio-economic model, FishRent, is used to estimate the effect of three policy scenarios: Fisheries regulation using individual transferable quotas (ITQ); Economic compensation provided to fishers for reducing nutrients; and Environmental regulation maximising sustainable catches. The results show that the highest social welfare gain is achieved by maximising catch volumes while having a flexible system for quota trade within the fishing sector. The social welfare gain from the positive externality of the extra fish landed in this case outweighs the private loss of not fishing at the optimal individual level (maximum economic yield).
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| 7. |
- Nielsen, Rasmus J., et al.
(author)
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Integrated ecological–economic fisheries models—Evaluation, review and challenges for implementation
- 2018
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In: Fish and Fisheries. - : Wiley. - 1467-2960 .- 1467-2979. ; 19:1, s. 1-29
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Research review (peer-reviewed)abstract
- Marine ecosystems evolve under many interconnected and area-specific pressures. To fulfil society's intensifying and diversifying needs while ensuring ecologically sustainable development, more effective marine spatial planning and broader-scope management of marine resources is necessary. Integrated ecological–economic fisheries models (IEEFMs) of marine systems are needed to evaluate impacts and sustainability of potential management actions and understand, and anticipate ecological, economic and social dynamics at a range of scales from local to national and regional. To make these models most effective, it is important to determine how model characteristics and methods of communicating results influence the model implementation, the nature of the advice that can be provided and the impact on decisions taken by managers. This article presents a global review and comparative evaluation of 35 IEEFMs applied to marine fisheries and marine ecosystem resources to identify the characteristics that determine their usefulness, effectiveness and implementation. The focus is on fully integrated models that allow for feedbacks between ecological and human processes although not all the models reviewed achieve that. Modellers must invest more time to make models user friendly and to participate in management fora where models and model results can be explained and discussed. Such involvement is beneficial to all parties, leading to improvement of models and more effective implementation of advice, but demands substantial resources which must be built into the governance process. It takes time to develop effective processes for using IEEFMs requiring a long-term commitment to integrating multidisciplinary modelling advice into management decision-making.
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