Search

Search Results

• 1. [Article] Fishing in a Shallow Lake: A Case for Effort Controls?

  In many situation, fishing activity adversely impacts the state of the marine ecosystem, impacts which feed back to affect fish stocks. Some ecosystems appear to have multiple equilibria and exhibit hysteresis, ...

  Citation × Citation Citation Abstract Copy Title: Fishing in a Shallow Lake: A Case for Effort Controls? Author: Janmaat, John, Ruijs, Arjan In many situation, fishing activity adversely impacts the state of the marine ecosystem, impacts which feed back to affect fish stocks. Some ecosystems appear to have multiple equilibria and exhibit hysteresis, whereby they can become stuck in low productivity states. We show how adding ecosystem dynamics to a classic fisheries model can introduce hysteresis impacts, impacts that affect both the evolution of the fish stock and the fishery harvesting it. We demonstrate that harvest and effort taxes are not equivalent instruments for controlling this externality. We also show that if the fishery is sufficiently degraded, it may not be optimal to move the system back to a healthy environment. Title: Fishing in a Shallow Lake: A Case for Effort Controls? Author: Janmaat, John, Ruijs, Arjan In many situation, fishing activity adversely impacts the state of the marine ecosystem, impacts which feed back to affect fish stocks. Some ecosystems appear to have multiple equilibria and exhibit hysteresis, whereby they can become stuck in low productivity states. We show how adding ecosystem dynamics to a classic fisheries model can introduce hysteresis impacts, impacts that affect both the evolution of the fish stock and the fishery harvesting it. We demonstrate that harvest and effort taxes are not equivalent instruments for controlling this externality. We also show that if the fishery is sufficiently degraded, it may not be optimal to move the system back to a healthy environment. Close

• 2. [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

• 3. [Article] Linking ecology, economics, and fleet dynamics to evaluate alternative management strategies for US West Coast trawl fisheries

  Abstract only.

  Citation × Citation Citation Abstract Copy Title: Linking ecology, economics, and fleet dynamics to evaluate alternative management strategies for US West Coast trawl fisheries Author: Kaplan, Isaac, Fulton, Elizabeth, Holland, Daniel Abstract only. Title: Linking ecology, economics, and fleet dynamics to evaluate alternative management strategies for US West Coast trawl fisheries Author: Kaplan, Isaac, Fulton, Elizabeth, Holland, Daniel Abstract only. Close

• 4. [Article] Can Catch Shares Prevent Fisheries Collapse?

  Abstract only.

  Citation × Citation Citation Abstract Copy Title: Can Catch Shares Prevent Fisheries Collapse? Author: Gaines, Steve, Costello, Chris, Lynham, John Abstract only. Title: Can Catch Shares Prevent Fisheries Collapse? Author: Gaines, Steve, Costello, Chris, Lynham, John Abstract only. Close

• 5. [Article] Tev (total Economic Value) Analysis of A Marine Environment in Norway

  The push for ecosystem based management has opened up not only for including more of the natural systems when managing fish resources, but also a broader perspective on the human systems, and the diverse ...

  Citation × Citation Citation Abstract Copy Title: Tev (total Economic Value) Analysis of A Marine Environment in Norway Author: Kahui, Viktoria, Armstrong, Claire, Aanesen, Margrethe The push for ecosystem based management has opened up not only for including more of the natural systems when managing fish resources, but also a broader perspective on the human systems, and the diverse activities in the sea. This is reflected for instance in the EU Maritime Policy where fisheries is just one of many activities that marine management must take into account. Research into valuation of natural resources has shown that non-use values may be substantial in the marine environment; These are e.g. existence values, such as the existence of rare species and benthic components such as corals, and option values with regard to potential future applications, e.g. in marine bioprospecting. In addition, indirect use values, such as habitat values, recreational values and nutrient cycling often far exceed the direct use values, which are typically the value of the fisheries, aquaculture and marine tourism. Applying and critiquing the Total Economic Value (TEV) set up, we have estimated marine direct use values, including fisheries and aquaculture, indirect use values and non-use values in Nordland county in Norway, specifically connected to the Lofoten-Vesterålen marine area. Lofoten-Vesterålen is the most important spawning ground for commercial fish resources such as cod and herring, and it is also a very popular tourist destination. Yet when studying some of the other values that the marine environment supplies, these traditional values are not necessarily the most important. Title: Tev (total Economic Value) Analysis of A Marine Environment in Norway Author: Kahui, Viktoria, Armstrong, Claire, Aanesen, Margrethe The push for ecosystem based management has opened up not only for including more of the natural systems when managing fish resources, but also a broader perspective on the human systems, and the diverse activities in the sea. This is reflected for instance in the EU Maritime Policy where fisheries is just one of many activities that marine management must take into account. Research into valuation of natural resources has shown that non-use values may be substantial in the marine environment; These are e.g. existence values, such as the existence of rare species and benthic components such as corals, and option values with regard to potential future applications, e.g. in marine bioprospecting. In addition, indirect use values, such as habitat values, recreational values and nutrient cycling often far exceed the direct use values, which are typically the value of the fisheries, aquaculture and marine tourism. Applying and critiquing the Total Economic Value (TEV) set up, we have estimated marine direct use values, including fisheries and aquaculture, indirect use values and non-use values in Nordland county in Norway, specifically connected to the Lofoten-Vesterålen marine area. Lofoten-Vesterålen is the most important spawning ground for commercial fish resources such as cod and herring, and it is also a very popular tourist destination. Yet when studying some of the other values that the marine environment supplies, these traditional values are not necessarily the most important. Close

• 6. [Article] A Proposed Framework for Identifying and Evaluating Ecosystem Service Tradeoffs for Marine Protected Area Planning

  Existing research on the effectiveness of marine protected areas narrowly focuses on developing sets of management indicators tied to outcomes described in management plans or on the achievement of a single ...

  Citation × Citation Citation Abstract Copy Title: A Proposed Framework for Identifying and Evaluating Ecosystem Service Tradeoffs for Marine Protected Area Planning Author: Harte, Michael, Heppell, Selina, Rosenberger, Randall, Sylvia, Gil Existing research on the effectiveness of marine protected areas narrowly focuses on developing sets of management indicators tied to outcomes described in management plans or on the achievement of a single objective such as an increase in the size or number of older, more fecund female fish in a protected area. These approaches, however, fail to capture the dynamic complexity of social, cultural, economic and ecological processes, uncertainty, and tradeoffs associated with the establishment and operation of marine protected areas. Moreover, there is usually little recognition of local coastal communities, including fishing communities, and the values they hold in the evaluation of the relative benefits and costs of marine protected areas. We describe a framework for evaluating and assessing economic and ecosystem tradeoffs associated with marine protected areas and other forms of marine spatial planning. This framework integrates biophysical data and community-based social and economic evaluation methods. It identifies ecosystem services, their benefits and associated uncertainties in assessing the economic and social tradeoffs associated with changes in the use of the marine environment. Title: A Proposed Framework for Identifying and Evaluating Ecosystem Service Tradeoffs for Marine Protected Area Planning Author: Harte, Michael, Heppell, Selina, Rosenberger, Randall, Sylvia, Gil Existing research on the effectiveness of marine protected areas narrowly focuses on developing sets of management indicators tied to outcomes described in management plans or on the achievement of a single objective such as an increase in the size or number of older, more fecund female fish in a protected area. These approaches, however, fail to capture the dynamic complexity of social, cultural, economic and ecological processes, uncertainty, and tradeoffs associated with the establishment and operation of marine protected areas. Moreover, there is usually little recognition of local coastal communities, including fishing communities, and the values they hold in the evaluation of the relative benefits and costs of marine protected areas. We describe a framework for evaluating and assessing economic and ecosystem tradeoffs associated with marine protected areas and other forms of marine spatial planning. This framework integrates biophysical data and community-based social and economic evaluation methods. It identifies ecosystem services, their benefits and associated uncertainties in assessing the economic and social tradeoffs associated with changes in the use of the marine environment. Close

• 7. [Article] Creation of Marine Reserve and Incentives for Biodiversity Conservation

  Abstract only.

  Citation × Citation Citation Abstract Copy Title: Creation of Marine Reserve and Incentives for Biodiversity Conservation Author: Quach, Thi Khanh Ngoc Abstract only. Title: Creation of Marine Reserve and Incentives for Biodiversity Conservation Author: Quach, Thi Khanh Ngoc Abstract only. Close

• 8. [Article] Spatial management of small-scale fisheries targeting metapopulations with source-sink configuration: a parsimonious ecosystem approach

  Abstract only.

  Citation × Citation Citation Abstract Copy Title: Spatial management of small-scale fisheries targeting metapopulations with source-sink configuration: a parsimonious ecosystem approach Author: Seijo, Juan Carlos Abstract only. Title: Spatial management of small-scale fisheries targeting metapopulations with source-sink configuration: a parsimonious ecosystem approach Author: Seijo, Juan Carlos Abstract only. Close

• 9. [Article] A comparative approach of long term changes in the characteristics of fisheries at a regional scale

  Abstract only.

  Citation × Citation Citation Abstract Copy Title: A comparative approach of long term changes in the characteristics of fisheries at a regional scale Author: Le Floc'h, Pascal, Malouli, Mohammed, Amrani, Mohammed, Thébaud, Olivier, Chaboud, Christian, Blanchard, Fabian, Maski, Hicham Abstract only. Title: A comparative approach of long term changes in the characteristics of fisheries at a regional scale Author: Le Floc'h, Pascal, Malouli, Mohammed, Amrani, Mohammed, Thébaud, Olivier, Chaboud, Christian, Blanchard, Fabian, Maski, Hicham Abstract only. Close

• 10. [Article] A Socio-Economic Toolbox of Artificial Reef Projects

  It is widely accepted that in sea bottom areas where there is a scarcity of rocky formations and declining marine fish due to fisheries pressure, the deployment of artificial reefs (ARs) is a possible ...

  Citation × Citation Citation Abstract Copy Title: A Socio-Economic Toolbox of Artificial Reef Projects Author: Monteiro, Carlos C., Santos, Miguel N., Whitmarsh, David, Ramos, Jorge It is widely accepted that in sea bottom areas where there is a scarcity of rocky formations and declining marine fish due to fisheries pressure, the deployment of artificial reefs (ARs) is a possible way to mitigate the problem. If ARs have an ecosystem-based fisheries management goal that means their presence is believed to be a sine qua non condition to maintain the sustainability of coastal ecosystems. However, decisions relating to the deployment and management of ARs arguably need to be guided by the dictum that ‘an artificial reef that is not useful to people is not a successful reef’. The issue of ‘AR usefulness’ is raised because there are many studies on reef assessment, but usually focusing solely on biological approaches. Thus, these approaches are usually not enough to prove or refute the above premise. So, it is of fundamental importance to involve the affected people, i.e., stakeholders. With that in mind, the present study presents a socio-economic ‘toolbox’ where it is intended to find out people’s involvement, belief, attitude and behavior concerning artificial reef’s deployment. The toolbox is based on a flexible research design and includes three types of assessment that can be done in the scope of social and economic evaluation of ARs, namely: (1) Monitoring and description, (2) Social analysis, and (3) Economic assessment. In each one there are used different data collection and measurement techniques. Title: A Socio-Economic Toolbox of Artificial Reef Projects Author: Monteiro, Carlos C., Santos, Miguel N., Whitmarsh, David, Ramos, Jorge It is widely accepted that in sea bottom areas where there is a scarcity of rocky formations and declining marine fish due to fisheries pressure, the deployment of artificial reefs (ARs) is a possible way to mitigate the problem. If ARs have an ecosystem-based fisheries management goal that means their presence is believed to be a sine qua non condition to maintain the sustainability of coastal ecosystems. However, decisions relating to the deployment and management of ARs arguably need to be guided by the dictum that ‘an artificial reef that is not useful to people is not a successful reef’. The issue of ‘AR usefulness’ is raised because there are many studies on reef assessment, but usually focusing solely on biological approaches. Thus, these approaches are usually not enough to prove or refute the above premise. So, it is of fundamental importance to involve the affected people, i.e., stakeholders. With that in mind, the present study presents a socio-economic ‘toolbox’ where it is intended to find out people’s involvement, belief, attitude and behavior concerning artificial reef’s deployment. The toolbox is based on a flexible research design and includes three types of assessment that can be done in the scope of social and economic evaluation of ARs, namely: (1) Monitoring and description, (2) Social analysis, and (3) Economic assessment. In each one there are used different data collection and measurement techniques. Close