Search

Search Results

• 11. [Article] The Cost of Avoiding Sea Cucumber Stock Depletion

  In 2013 a stock of sea cucumber (Isostichopus badionotus) was discovered in northern shelf of Yucatan. A survey calculated a biomass of 17,600 tons. The species has an attractive price for local fishers, ...

  Citation × Citation Citation Abstract Copy Title: The Cost of Avoiding Sea Cucumber Stock Depletion Author: Hernández-Flores, Alvaro, Cuevas-Jiménez, Alfonso, Aranda-Nah, Javier In 2013 a stock of sea cucumber (Isostichopus badionotus) was discovered in northern shelf of Yucatan. A survey calculated a biomass of 17,600 tons. The species has an attractive price for local fishers, therefore, in order to avoid the “race for sea cucumbers” and the collapse of the stock, authorities established a total quota of 1,278 tones, issued a limited number of permits and restricted the fishing season to six weeks. Because of fishers’ dynamic behavior and the installed local fishing capacity, the applied effort was higher than the authorized (750 boats per day). Regulations were not enough to avoid excess fishing and entry of non-authorized boats, driving the stock to a low level. We developed a spatial and density dependent bioeconomic model which calculates an optimum pathway to maximize the profits without putting the stock in peril. The model operates seasonally in the short-run. Because of catchability and cost depend on the sea cucumbers densities, both were modeled with asymptotic functions. In order to avoid the Allee effect, the species requires a minimum density of 0.1 individuals per square meter. Our results indicate that the maximum quota could be 5,700 tons, which is about 32% of the vulnerable biomass. This quota would produce profits of US$2,300,000. If minimum density were neglected, the system would lead the biomass to 8,400 tons, instead 11,000 tons, with extra profits of US$76,000; however, in such level the density would be 0.08 individual per square meter, reaching the Allee effect and impeding the stock recovery. Title: The Cost of Avoiding Sea Cucumber Stock Depletion Author: Hernández-Flores, Alvaro, Cuevas-Jiménez, Alfonso, Aranda-Nah, Javier In 2013 a stock of sea cucumber (Isostichopus badionotus) was discovered in northern shelf of Yucatan. A survey calculated a biomass of 17,600 tons. The species has an attractive price for local fishers, therefore, in order to avoid the “race for sea cucumbers” and the collapse of the stock, authorities established a total quota of 1,278 tones, issued a limited number of permits and restricted the fishing season to six weeks. Because of fishers’ dynamic behavior and the installed local fishing capacity, the applied effort was higher than the authorized (750 boats per day). Regulations were not enough to avoid excess fishing and entry of non-authorized boats, driving the stock to a low level. We developed a spatial and density dependent bioeconomic model which calculates an optimum pathway to maximize the profits without putting the stock in peril. The model operates seasonally in the short-run. Because of catchability and cost depend on the sea cucumbers densities, both were modeled with asymptotic functions. In order to avoid the Allee effect, the species requires a minimum density of 0.1 individuals per square meter. Our results indicate that the maximum quota could be 5,700 tons, which is about 32% of the vulnerable biomass. This quota would produce profits of US$2,300,000. If minimum density were neglected, the system would lead the biomass to 8,400 tons, instead 11,000 tons, with extra profits of US$76,000; however, in such level the density would be 0.08 individual per square meter, reaching the Allee effect and impeding the stock recovery. Close

• 12. [Article] Fish consumption within the Finnish catering market

  Research Paper

  Citation × Citation Citation Abstract Copy Title: Fish consumption within the Finnish catering market Author: Honkanen, Asmo Research Paper Title: Fish consumption within the Finnish catering market Author: Honkanen, Asmo Research Paper Close

• 13. [Article] Comprehensive Fishery Wealth: A Bioeconomic, Ecosystem-Based Approach to Measuring Fisheries Sustainability

  Fisheries sustainability is a much sought-after goal. Yet, “sustainability” is often too ambiguously defined to be of much practical guidance to policymakers. Furthermore, fisheries managers are increasingly ...

  Citation × Citation Citation Abstract Copy Title: Comprehensive Fishery Wealth: A Bioeconomic, Ecosystem-Based Approach to Measuring Fisheries Sustainability Author: Fenichel, Eli P., Abbott, Joshua K. Fisheries sustainability is a much sought-after goal. Yet, “sustainability” is often too ambiguously defined to be of much practical guidance to policymakers. Furthermore, fisheries managers are increasingly expected to assess and manage fisheries in an “ecosystem-based” manner – accounting for the ecological interdependencies of species and their coupling with the physical environment. We build upon the green accounting and sustainable development literatures to downscale indices often used to measure sustainability at the nation-state scale to measure the current and projected future sustainability of exploited fishery ecosystems. We argue that the sustainability of a fishery ecosystem can be assessed by whether the properly measured value of the natural, physical and human capital stocks embodied within the fishery (i.e., the comprehensive fishery wealth) is non-decreasing over time. We extend our published work (Fenichel and Abbott 2014) to show how ecosystem models of fisheries can be integrated with bioeconomic models of human “predators’” responses to changes in multispecies fish stocks and policy to provide rigorous “shadow prices” for all species within the system and fishing capital. These prices can then be multiplied by their associated capital stocks to provide an index of inclusive fishery wealth. Changes in this index (i.e., comprehensive investment) allow managers to assess the ability of past and current fishery management regimes to maintain wealth within the fishery for future generations. Finally, we show how our wealth accounting approach – when coupled with ecosystem-based bioeconomic models – can be leveraged to prospectively evaluate the sustainability and efficiency of alternative management approaches. Title: Comprehensive Fishery Wealth: A Bioeconomic, Ecosystem-Based Approach to Measuring Fisheries Sustainability Author: Fenichel, Eli P., Abbott, Joshua K. Fisheries sustainability is a much sought-after goal. Yet, “sustainability” is often too ambiguously defined to be of much practical guidance to policymakers. Furthermore, fisheries managers are increasingly expected to assess and manage fisheries in an “ecosystem-based” manner – accounting for the ecological interdependencies of species and their coupling with the physical environment. We build upon the green accounting and sustainable development literatures to downscale indices often used to measure sustainability at the nation-state scale to measure the current and projected future sustainability of exploited fishery ecosystems. We argue that the sustainability of a fishery ecosystem can be assessed by whether the properly measured value of the natural, physical and human capital stocks embodied within the fishery (i.e., the comprehensive fishery wealth) is non-decreasing over time. We extend our published work (Fenichel and Abbott 2014) to show how ecosystem models of fisheries can be integrated with bioeconomic models of human “predators’” responses to changes in multispecies fish stocks and policy to provide rigorous “shadow prices” for all species within the system and fishing capital. These prices can then be multiplied by their associated capital stocks to provide an index of inclusive fishery wealth. Changes in this index (i.e., comprehensive investment) allow managers to assess the ability of past and current fishery management regimes to maintain wealth within the fishery for future generations. Finally, we show how our wealth accounting approach – when coupled with ecosystem-based bioeconomic models – can be leveraged to prospectively evaluate the sustainability and efficiency of alternative management approaches. Close

• 14. [Article] The Effects of Derelict Gear on Blue Crab Production in the Chesapeake Bay

  Several factors currently threaten blue crab (Callinectes sapidus) in the Chesapeake Bay. In addition to poor water quality, degraded habitat, and shifting environmental conditions, derelict gear has recently ...

  Citation × Citation Citation Abstract Copy Title: The Effects of Derelict Gear on Blue Crab Production in the Chesapeake Bay Author: Bilkovic, Donna M., Scheld, Andrew M., Havens, Kirk J. Several factors currently threaten blue crab (Callinectes sapidus) in the Chesapeake Bay. In addition to poor water quality, degraded habitat, and shifting environmental conditions, derelict gear has recently been recognized as a significant source of mortality for this economically and culturally significant species. From 2008 through 2014, commercial watermen in Virginia were hired during their winter off season to locate, document, and remove derelict gear as part of a larger research effort to determine the biological impacts of marine debris in the Chesapeake Bay. Data on derelict gear removal generated by this research was subsequently paired with spatially resolved catch and effort data and entered into a translog production model used to estimate the economic effects of derelict gear on commercial blue crab production. Model results indicate removal significantly improved pot production and economic profits, a finding which had been previously confounded by concurrent blue crab management action. Our research builds on previous work through explicit acknowledgment of important spatial production differences and incorporation of derelict gear removal. Title: The Effects of Derelict Gear on Blue Crab Production in the Chesapeake Bay Author: Bilkovic, Donna M., Scheld, Andrew M., Havens, Kirk J. Several factors currently threaten blue crab (Callinectes sapidus) in the Chesapeake Bay. In addition to poor water quality, degraded habitat, and shifting environmental conditions, derelict gear has recently been recognized as a significant source of mortality for this economically and culturally significant species. From 2008 through 2014, commercial watermen in Virginia were hired during their winter off season to locate, document, and remove derelict gear as part of a larger research effort to determine the biological impacts of marine debris in the Chesapeake Bay. Data on derelict gear removal generated by this research was subsequently paired with spatially resolved catch and effort data and entered into a translog production model used to estimate the economic effects of derelict gear on commercial blue crab production. Model results indicate removal significantly improved pot production and economic profits, a finding which had been previously confounded by concurrent blue crab management action. Our research builds on previous work through explicit acknowledgment of important spatial production differences and incorporation of derelict gear removal. Close

• 15. [Article] Measuring Productivity Change and its Components for Fisheries: The Alaskan Pollock Fishery, 1994-2003

  Research Paper

  Citation × Citation Citation Abstract Copy Title: Measuring Productivity Change and its Components for Fisheries: The Alaskan Pollock Fishery, 1994-2003 Author: Morrison-Paul, Catherine, Torres, Marcelo Research Paper Title: Measuring Productivity Change and its Components for Fisheries: The Alaskan Pollock Fishery, 1994-2003 Author: Morrison-Paul, Catherine, Torres, Marcelo Research Paper Close

• 16. [Article] Bioeconomic Analysis of the Artisanal Shrimp Trawl Fishery in the Tonkin Gulf, Vietnam

  Research Paper

  Citation × Citation Citation Abstract Copy Title: Bioeconomic Analysis of the Artisanal Shrimp Trawl Fishery in the Tonkin Gulf, Vietnam Author: Eide, Arne, Thanh, Nguyen Viet Research Paper Title: Bioeconomic Analysis of the Artisanal Shrimp Trawl Fishery in the Tonkin Gulf, Vietnam Author: Eide, Arne, Thanh, Nguyen Viet Research Paper Close

• 17. [Article] Sustainable Management of the Shrimp Trawl Fishery in Tonkin Gulf, Vietnam

  This study investigates the sustainability of shrimp stock in the trawl fishery in the Tonkin Gulf, Vietnam. It is a small scale and multi species fishery. The Verhulst-Schaefer and Gompertz-Fox surplus ...

  Citation × Citation Citation Abstract Copy Title: Sustainable Management of the Shrimp Trawl Fishery in Tonkin Gulf, Vietnam Author: Nguyen, Viet Thanh This study investigates the sustainability of shrimp stock in the trawl fishery in the Tonkin Gulf, Vietnam. It is a small scale and multi species fishery. The Verhulst-Schaefer and Gompertz-Fox surplus production models are applied. There are two shrimp spawning seasons in a year in the Gulf. Therefore, in this study, the surplus production models, associated to catch calendar and effort data, are applied for a half-year time interval. The results indicate that the fishing effort should be reduced by roughly 12-44% to achieve the maximum sustainable yield and 46-61% to reach the maximum economic yield. With a social discount rate of 10%, the effort should decrease by around 45-56% to achieve the optimal yield. The entry tax should be 92-279 USD/month/boat to achieve the maximum sustainable yield and 160-314 USD/month/boat to attain the maximum economic yield. Title: Sustainable Management of the Shrimp Trawl Fishery in Tonkin Gulf, Vietnam Author: Nguyen, Viet Thanh This study investigates the sustainability of shrimp stock in the trawl fishery in the Tonkin Gulf, Vietnam. It is a small scale and multi species fishery. The Verhulst-Schaefer and Gompertz-Fox surplus production models are applied. There are two shrimp spawning seasons in a year in the Gulf. Therefore, in this study, the surplus production models, associated to catch calendar and effort data, are applied for a half-year time interval. The results indicate that the fishing effort should be reduced by roughly 12-44% to achieve the maximum sustainable yield and 46-61% to reach the maximum economic yield. With a social discount rate of 10%, the effort should decrease by around 45-56% to achieve the optimal yield. The entry tax should be 92-279 USD/month/boat to achieve the maximum sustainable yield and 160-314 USD/month/boat to attain the maximum economic yield. Close

• 18. [Article] American consumers’ eating patterns of fish and knowledge of fish rich in omega-3 fatty acids

  Research Paper

  Citation × Citation Citation Abstract Copy Title: American consumers’ eating patterns of fish and knowledge of fish rich in omega-3 fatty acids Author: Martin, Anna B., Kudo, Koei Research Paper Title: American consumers’ eating patterns of fish and knowledge of fish rich in omega-3 fatty acids Author: Martin, Anna B., Kudo, Koei Research Paper Close

• 19. [Article] Can the Knowledge Society Turn Around 500 Years of Overfishing?

  Research Paper

  Citation × Citation Citation Abstract Copy Title: Can the Knowledge Society Turn Around 500 Years of Overfishing? Author: Froese, Rainer, Stern-Pirlot, Amanda Research Paper Title: Can the Knowledge Society Turn Around 500 Years of Overfishing? Author: Froese, Rainer, Stern-Pirlot, Amanda Research Paper Close

• 20. [Article] Regulatory Compliance in Lake Victoria Fisheries

  Research Paper

  Citation × Citation Citation Abstract Copy Title: Regulatory Compliance in Lake Victoria Fisheries Author: Eggert, Hakan, Lokina, Razack Research Paper Title: Regulatory Compliance in Lake Victoria Fisheries Author: Eggert, Hakan, Lokina, Razack Research Paper Close