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• 1. [Article] Optimal Management of the Baltic Sea Fishery Under Climate Change: An Ecological-Economic Age-Structured Multi-Species Model Analysis

  Abstract only.

  Citation × Citation Citation Abstract Copy Title: Optimal Management of the Baltic Sea Fishery Under Climate Change: An Ecological-Economic Age-Structured Multi-Species Model Analysis Author: Voss, Rüdiger, Neuenfeldt, Stefan, Quaas, Martin F., Schmidt, Jörn O. Abstract only. Title: Optimal Management of the Baltic Sea Fishery Under Climate Change: An Ecological-Economic Age-Structured Multi-Species Model Analysis Author: Voss, Rüdiger, Neuenfeldt, Stefan, Quaas, Martin F., Schmidt, Jörn O. Abstract only. Close

• 2. [Article] The Stability of Rent Maximization in the Western and Central Pacific Fishery

  The potential for achieving sustainable and efficient harvesting of three species of migratory tuna in the Western and Central Pacific Ocean is examined. The stocks reside in exclusive economic zones (mainly ...

  Citation × Citation Citation Abstract Copy Title: The Stability of Rent Maximization in the Western and Central Pacific Fishery Author: Kennedy, John, Hannesson, Rögnvaldur The potential for achieving sustainable and efficient harvesting of three species of migratory tuna in the Western and Central Pacific Ocean is examined. The stocks reside in exclusive economic zones (mainly those of Pacific island countries) and in the high seas. Most harvesting is carried out by distant water fishing nations, including the USA, Japan, Taiwan, China and Korea. Problems of achieving sustainability and efficiency in the harvesting of the stocks by disparate countries are made more difficult due to changes in the harvesting levels of one fleet affecting the rents of another fleet through changes in the age distribution of stock. These types of problem are under review by the Western and Central Pacific Fisheries Commission. Results from an age-structured steady-state bioeconomic model are used to show: the changes in fleet rents and catches of tuna if all fleets form a cooperative grand coalition to deploy fishing effort to maximize rents over the region; the likely non-stability of the grand coalition; and the inferior Nash Equilibria outcomes if fleets fish non-cooperatively to maximize their own rents. Title: The Stability of Rent Maximization in the Western and Central Pacific Fishery Author: Kennedy, John, Hannesson, Rögnvaldur The potential for achieving sustainable and efficient harvesting of three species of migratory tuna in the Western and Central Pacific Ocean is examined. The stocks reside in exclusive economic zones (mainly those of Pacific island countries) and in the high seas. Most harvesting is carried out by distant water fishing nations, including the USA, Japan, Taiwan, China and Korea. Problems of achieving sustainability and efficiency in the harvesting of the stocks by disparate countries are made more difficult due to changes in the harvesting levels of one fleet affecting the rents of another fleet through changes in the age distribution of stock. These types of problem are under review by the Western and Central Pacific Fisheries Commission. Results from an age-structured steady-state bioeconomic model are used to show: the changes in fleet rents and catches of tuna if all fleets form a cooperative grand coalition to deploy fishing effort to maximize rents over the region; the likely non-stability of the grand coalition; and the inferior Nash Equilibria outcomes if fleets fish non-cooperatively to maximize their own rents. Close

• 3. [Article] Age Structure Metrics for Precautionary Management: Can Simpler Assessment Techniques Save Fish, Time, and Money?

  Stock assessment techniques currently used in the United States are extremely costly to implement, involve significant data requirements, and are inaccessible to all but a few stock assessment scientists. ...

  Citation × Citation Citation Abstract Copy Title: Age Structure Metrics for Precautionary Management: Can Simpler Assessment Techniques Save Fish, Time, and Money? Author: Harte, Michael, Heppell, Selina, Sylvia, Gil, Cusack, Christopher, Larkin, Sherry Stock assessment techniques currently used in the United States are extremely costly to implement, involve significant data requirements, and are inaccessible to all but a few stock assessment scientists. A systematic decrease in fishery yields and the designation of several species as overfished on the west coast of the United States have resulted in stricter protocols regarding sustainable fisheries management and the rebuilding of overfished stocks, including the need to set annual harvest limits for all exploited species. An alternative and simpler approach to stock assessment which could address this need is described and an evaluation framework set up. Although no results have been obtained to date, possible costs and benefits of incorporating this approach into fisheries management are discussed. Title: Age Structure Metrics for Precautionary Management: Can Simpler Assessment Techniques Save Fish, Time, and Money? Author: Harte, Michael, Heppell, Selina, Sylvia, Gil, Cusack, Christopher, Larkin, Sherry Stock assessment techniques currently used in the United States are extremely costly to implement, involve significant data requirements, and are inaccessible to all but a few stock assessment scientists. A systematic decrease in fishery yields and the designation of several species as overfished on the west coast of the United States have resulted in stricter protocols regarding sustainable fisheries management and the rebuilding of overfished stocks, including the need to set annual harvest limits for all exploited species. An alternative and simpler approach to stock assessment which could address this need is described and an evaluation framework set up. Although no results have been obtained to date, possible costs and benefits of incorporating this approach into fisheries management are discussed. Close

• 4. [Article] Implications of bycatch reduction strategies for the economic viability of mixed fisheries

  There is growing recognition worldwide that the impacts of fishing on non-targeted components of marine ecosystems should be included in the assessment of fisheries sustainability. This leads to the inclusion ...

  Citation × Citation Citation Abstract Copy Title: Implications of bycatch reduction strategies for the economic viability of mixed fisheries Author: Thebaud, Olivier, Martinet, Vincent There is growing recognition worldwide that the impacts of fishing on non-targeted components of marine ecosystems should be included in the assessment of fisheries sustainability. This leads to the inclusion of new constraints in evaluations of the long-term bio-economic performance of fisheries. In this paper, we analyze the implications of such constraints based on the case of bycatch of juvenile hake in the Bay of Biscay (ICES area VIIIa,b) trawl fishery for nephrops. The analysis is based on a discrete time model of the trawl fishery including an age-structured representation of stock dynamics, with uncertainty. We define sustainability using the viability framework of analysis: viability objectives are represented as constraints which relate to the economic status of the fishing fleet and to the biological status of fish stocks. We include an ecological constraint defined as a minimal target threshold for the recruitment of mature hakes, which is related to the fishing mortality induced by trawlers on juvenile hake. Based on stochastic analysis, we define the probability that both economic and ecosystemic constraints are met, as a function of the level of these constraints. We use the model to assess the sustainability of the fishery under different scenarios as regards bycatch reduction strategies. Title: Implications of bycatch reduction strategies for the economic viability of mixed fisheries Author: Thebaud, Olivier, Martinet, Vincent There is growing recognition worldwide that the impacts of fishing on non-targeted components of marine ecosystems should be included in the assessment of fisheries sustainability. This leads to the inclusion of new constraints in evaluations of the long-term bio-economic performance of fisheries. In this paper, we analyze the implications of such constraints based on the case of bycatch of juvenile hake in the Bay of Biscay (ICES area VIIIa,b) trawl fishery for nephrops. The analysis is based on a discrete time model of the trawl fishery including an age-structured representation of stock dynamics, with uncertainty. We define sustainability using the viability framework of analysis: viability objectives are represented as constraints which relate to the economic status of the fishing fleet and to the biological status of fish stocks. We include an ecological constraint defined as a minimal target threshold for the recruitment of mature hakes, which is related to the fishing mortality induced by trawlers on juvenile hake. Based on stochastic analysis, we define the probability that both economic and ecosystemic constraints are met, as a function of the level of these constraints. We use the model to assess the sustainability of the fishery under different scenarios as regards bycatch reduction strategies. Close

• 5. [Article] Individual Perception of the Impact of Fishing on Halieutic Resources: European Evidence

  Our paper aims to study the image of the European fisheries sector, as perceived by European citizens. To our knowledge, no approach has focused on the perceived impact of fishing on the halieutic resources. ...

  Citation × Citation Citation Abstract Copy Title: Individual Perception of the Impact of Fishing on Halieutic Resources: European Evidence Author: Perraudeau, Yves, Salladarré, Frédéric, Hlaimi, Boubaker Our paper aims to study the image of the European fisheries sector, as perceived by European citizens. To our knowledge, no approach has focused on the perceived impact of fishing on the halieutic resources. More precisely, we seek to analyze the perceived impact on the marine environment of fishing activities in 5 European countries. Basing on a European sample, we examine the determinants of individual perceptions of the fishing impact on halieutic resources. Moreover, in order to put forward common and national specificities, we estimate the perceived impact for the five countries separately. We evidence that sociodemographic characteristics do not show significant effects on the perception except for age where young people seem to be more sensitive to this ecological issue. However, the perceived impact of fishing on halieutic resources is positively associated to the extent of fishing activities, whereas pollution and global warming surprisingly do not exert significant influence: this result implies that only fishing activities are perceived as having an impact on the biomass. In addition, our estimates show that the subjective impact on halieutic resources is positively influenced by the perceived level of fishing regulation, while an increasing time spent in seaside reduces it. Finally, we show the existence of important national differences in the way in which individuals apprehend the impact of fishing activities on the marine environment. Whereas Italy occupies an intermediate position, Denmark and France are characterized by a more favourable awareness of the perception of the fishing impact than Belgium and the Netherlands. Title: Individual Perception of the Impact of Fishing on Halieutic Resources: European Evidence Author: Perraudeau, Yves, Salladarré, Frédéric, Hlaimi, Boubaker Our paper aims to study the image of the European fisheries sector, as perceived by European citizens. To our knowledge, no approach has focused on the perceived impact of fishing on the halieutic resources. More precisely, we seek to analyze the perceived impact on the marine environment of fishing activities in 5 European countries. Basing on a European sample, we examine the determinants of individual perceptions of the fishing impact on halieutic resources. Moreover, in order to put forward common and national specificities, we estimate the perceived impact for the five countries separately. We evidence that sociodemographic characteristics do not show significant effects on the perception except for age where young people seem to be more sensitive to this ecological issue. However, the perceived impact of fishing on halieutic resources is positively associated to the extent of fishing activities, whereas pollution and global warming surprisingly do not exert significant influence: this result implies that only fishing activities are perceived as having an impact on the biomass. In addition, our estimates show that the subjective impact on halieutic resources is positively influenced by the perceived level of fishing regulation, while an increasing time spent in seaside reduces it. Finally, we show the existence of important national differences in the way in which individuals apprehend the impact of fishing activities on the marine environment. Whereas Italy occupies an intermediate position, Denmark and France are characterized by a more favourable awareness of the perception of the fishing impact than Belgium and the Netherlands. Close