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• 1. [Article] Uncertainty and Risk in the Ecosystems Approach to Fisheries Management: Some Insights from an Ecosystem Computer Simulation Model

  Understanding the complexities of ecosystems is difficult enough, but when the human dimension is added to the inherent uncertainty and risk in fisheries management, the actual versus expected results ...

  Citation × Citation Citation Abstract Copy Title: Uncertainty and Risk in the Ecosystems Approach to Fisheries Management: Some Insights from an Ecosystem Computer Simulation Model Author: Ward, John, Metzner, Rebecca, DeYoung, Cassandra Understanding the complexities of ecosystems is difficult enough, but when the human dimension is added to the inherent uncertainty and risk in fisheries management, the actual versus expected results move from the counter-intuitive to the paradoxical. Without an adequate understanding of the interrelationships between ecosystem components, including the human dimension, scientific management becomes intuition-based management, which is often counterproductive to achieving desired goals and objectives. A computer simulation model is developed for multiple species, resource areas, stocks, and cohorts. To explicitly incorporate ecosystem effects predator-prey and competitor relationships are constructed to interpret interactions between different species of fish. Fishing fleet dynamics are captured by modeling multiple vessel classes based on specifications for catchability and concentration profiles. Additional uncertainty is included through the effects of market supply and demand on price for different discount rates. Economic impacts are also estimated for each point in time as biological and market conditions change. This simulation model results are then compared to determine if the management objective of maximization of net benefits subject to the fish stock conservation goal are achievable in an ecosystem context while also considering impacts on jobs, income, and sales. Insights from this simulation of an ecosystem should provide information on the needed research required for the ecosystem approach to fisheries management to be successful in achieving its multiple objectives. Title: Uncertainty and Risk in the Ecosystems Approach to Fisheries Management: Some Insights from an Ecosystem Computer Simulation Model Author: Ward, John, Metzner, Rebecca, DeYoung, Cassandra Understanding the complexities of ecosystems is difficult enough, but when the human dimension is added to the inherent uncertainty and risk in fisheries management, the actual versus expected results move from the counter-intuitive to the paradoxical. Without an adequate understanding of the interrelationships between ecosystem components, including the human dimension, scientific management becomes intuition-based management, which is often counterproductive to achieving desired goals and objectives. A computer simulation model is developed for multiple species, resource areas, stocks, and cohorts. To explicitly incorporate ecosystem effects predator-prey and competitor relationships are constructed to interpret interactions between different species of fish. Fishing fleet dynamics are captured by modeling multiple vessel classes based on specifications for catchability and concentration profiles. Additional uncertainty is included through the effects of market supply and demand on price for different discount rates. Economic impacts are also estimated for each point in time as biological and market conditions change. This simulation model results are then compared to determine if the management objective of maximization of net benefits subject to the fish stock conservation goal are achievable in an ecosystem context while also considering impacts on jobs, income, and sales. Insights from this simulation of an ecosystem should provide information on the needed research required for the ecosystem approach to fisheries management to be successful in achieving its multiple objectives. Close

• 2. [Article] Fishery Management When Biological and Economic Disturbances Are Correlated

  Economists studying the management of fisheries have universally assumed disturbances affecting harvest costs are unrelated to disturbances affecting biological growth. This paper gives examples of commercially ...

  Citation × Citation Citation Abstract Copy Title: Fishery Management When Biological and Economic Disturbances Are Correlated Author: Kennedy, Chris J. Economists studying the management of fisheries have universally assumed disturbances affecting harvest costs are unrelated to disturbances affecting biological growth. This paper gives examples of commercially valuable species that are impacted reproductively and behaviorally by a single environmental variable (e.g., temperature), leading to correlated disturbances in current marginal harvest costs and future biological growth. A general analytical model examines the importance of considering correlated disturbances when choosing optimal escapement targets, and shows how the presence of correlation affects the value of waiting for information on harvest costs. These results give insight as to the appropriate use of "self-correcting" mechanisms for controlling harvest, such as landing fees, versus hard targets, and provide a framework for proactive management of fisheries in the face of large-scale marine disturbances that can affect both the biological growth and behavior of commercially valuable species. Title: Fishery Management When Biological and Economic Disturbances Are Correlated Author: Kennedy, Chris J. Economists studying the management of fisheries have universally assumed disturbances affecting harvest costs are unrelated to disturbances affecting biological growth. This paper gives examples of commercially valuable species that are impacted reproductively and behaviorally by a single environmental variable (e.g., temperature), leading to correlated disturbances in current marginal harvest costs and future biological growth. A general analytical model examines the importance of considering correlated disturbances when choosing optimal escapement targets, and shows how the presence of correlation affects the value of waiting for information on harvest costs. These results give insight as to the appropriate use of "self-correcting" mechanisms for controlling harvest, such as landing fees, versus hard targets, and provide a framework for proactive management of fisheries in the face of large-scale marine disturbances that can affect both the biological growth and behavior of commercially valuable species. Close

• 3. [Article] A Stochastic Viability Approach for Ecosystem-Based Management of Mixed Fisheries: The Case of The Bay of Biscay Demersal Fisheries

  Abstract only.

  Citation × Citation Citation Abstract Copy Title: A Stochastic Viability Approach for Ecosystem-Based Management of Mixed Fisheries: The Case of The Bay of Biscay Demersal Fisheries Author: Gourguet, Sophie, Doyen, Luc, Thébaud, Olivier, Macher, Claire, Guyader, Olivier Abstract only. Title: A Stochastic Viability Approach for Ecosystem-Based Management of Mixed Fisheries: The Case of The Bay of Biscay Demersal Fisheries Author: Gourguet, Sophie, Doyen, Luc, Thébaud, Olivier, Macher, Claire, Guyader, Olivier Abstract only. Close