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• 1. [Article] Modeling Heterogeneous Fishing Fleet in an Ecosystem Based Management Context

  Multispecies fisheries pose a considerable management difficulty with respect to quota allocation between species. Externalities of direct control over the harvest may include, among others, creation of ...

  Citation × Citation Citation Abstract Copy Title: Modeling Heterogeneous Fishing Fleet in an Ecosystem Based Management Context Author: Hutniczak, Barbara Multispecies fisheries pose a considerable management difficulty with respect to quota allocation between species. Externalities of direct control over the harvest may include, among others, creation of unbalanced predator‐prey relationships in the environment. That, in turn, may affect the individual economic incentives of fishing vessels. Combining economic and ecological factors in one model has multiple advantages, whereas there have been little attempts to coordinate setting the total allowable catches in multispecies fisheries, particularly in the context of individual decision‐making process. The objective of this article is to develop a methodological framework for multispecies modeling with integrated ecological and economic realism suitable to evaluate the long term implications of the imposed regulations that can be used for better policy guidance. An empirical application is provided for the central Baltic Sea with its interacting fish community dominated by three species: cod, herring and sprat. The developed model includes three separate, dynamically updating, age‐structured submodels for each species, which are linked through predation. The harvest component is associated with the fishing vessels that optimize individual behavior subject to regulations, owned capital and individual technical efficiency derived with the use of a multiproduct distance function. The findings present a clear picture of asymmetries between vessels with respect to harvest process and reveal the rational harvest strategy that is accommodated in the multispecies simulation model. Title: Modeling Heterogeneous Fishing Fleet in an Ecosystem Based Management Context Author: Hutniczak, Barbara Multispecies fisheries pose a considerable management difficulty with respect to quota allocation between species. Externalities of direct control over the harvest may include, among others, creation of unbalanced predator‐prey relationships in the environment. That, in turn, may affect the individual economic incentives of fishing vessels. Combining economic and ecological factors in one model has multiple advantages, whereas there have been little attempts to coordinate setting the total allowable catches in multispecies fisheries, particularly in the context of individual decision‐making process. The objective of this article is to develop a methodological framework for multispecies modeling with integrated ecological and economic realism suitable to evaluate the long term implications of the imposed regulations that can be used for better policy guidance. An empirical application is provided for the central Baltic Sea with its interacting fish community dominated by three species: cod, herring and sprat. The developed model includes three separate, dynamically updating, age‐structured submodels for each species, which are linked through predation. The harvest component is associated with the fishing vessels that optimize individual behavior subject to regulations, owned capital and individual technical efficiency derived with the use of a multiproduct distance function. The findings present a clear picture of asymmetries between vessels with respect to harvest process and reveal the rational harvest strategy that is accommodated in the multispecies simulation model. Close

• 2. [Article] The Economic Cost of Ignoring Fishery Induced Evolution

  Ecologists warn that the rapid evolution occurring as a result of high-intensity commercial fishing could have potentially disastrous economic and ecological effects. The evolution of economically relevant ...

  Citation × Citation Citation Abstract Copy Title: The Economic Cost of Ignoring Fishery Induced Evolution Author: Faig, Amanda D. Ecologists warn that the rapid evolution occurring as a result of high-intensity commercial fishing could have potentially disastrous economic and ecological effects. The evolution of economically relevant life-history traits in fish, which can occur due to the harvesting pressure from commercial fisheries, can irreversibly diminish fisheries yields and ecological services. I model the interactions between the genetics, population structure, and economics of the fishery in order to determine whether the economic implications of this rapid evolution (called fisheries-induced evolution or FIE) are as potentially consequential as ecologists predict. My model is based on North-East Arctic Cod, which are long lived and for which an abundance of information exists, including proof of FIE. I compare the steady state reached by a `myopic’ fishery manager who sets effort and mesh size policy while ignoring evolution, to one who dynamically optimizes his strategy with the knowledge of how evolution will respond. This paper shows that ignoring evolution may lead to some profit loss, but not likely the `catastrophic’ amount of loss predicted by biologists. While the value of the fishery is somewhat improved when evolution is accounted for, an important auxiliary benefit of accounting for evolution is that the fish stock is healthier, with a larger biomass and a more balanced age-structure. Thus while, in a narrow sense, accounting for the evolutionary effects of fishing may yield only modest gains in the present value of returns, there may be broader reasons for fisheries managers to adopt policies that incorporate knowledge of FIE. Title: The Economic Cost of Ignoring Fishery Induced Evolution Author: Faig, Amanda D. Ecologists warn that the rapid evolution occurring as a result of high-intensity commercial fishing could have potentially disastrous economic and ecological effects. The evolution of economically relevant life-history traits in fish, which can occur due to the harvesting pressure from commercial fisheries, can irreversibly diminish fisheries yields and ecological services. I model the interactions between the genetics, population structure, and economics of the fishery in order to determine whether the economic implications of this rapid evolution (called fisheries-induced evolution or FIE) are as potentially consequential as ecologists predict. My model is based on North-East Arctic Cod, which are long lived and for which an abundance of information exists, including proof of FIE. I compare the steady state reached by a `myopic’ fishery manager who sets effort and mesh size policy while ignoring evolution, to one who dynamically optimizes his strategy with the knowledge of how evolution will respond. This paper shows that ignoring evolution may lead to some profit loss, but not likely the `catastrophic’ amount of loss predicted by biologists. While the value of the fishery is somewhat improved when evolution is accounted for, an important auxiliary benefit of accounting for evolution is that the fish stock is healthier, with a larger biomass and a more balanced age-structure. Thus while, in a narrow sense, accounting for the evolutionary effects of fishing may yield only modest gains in the present value of returns, there may be broader reasons for fisheries managers to adopt policies that incorporate knowledge of FIE. Close