Pub Date : 2012-06-27DOI: 10.1080/10641262.2012.695816
K. Stokesbury
The United States sea scallop management plan applies fishing mortality in a uniform manner, assigning a single value of instantaneous fishing mortality (F) to the entire resource. Applying a single value of fishing mortality assumes the scallop resource is a single population. Dividing the resource into Georges Bank and Mid-Atlantic Bight reveals that each has been either excessively fished or underutilized based on the present definition of optimum yield. The sea scallop resource was highest in 2003 and has declined by about 50,000 metric tons, entirely from the Mid-Atlantic Bight. Abundance and the corresponding harvest levels will likely continue if the resource is a single population and scallops in the closed areas of Georges Bank populate the entire resource. Abundance and the corresponding harvest levels will likely decline if Georges Bank and the Mid-Atlantic Bight are separate populations in that scallops within these areas have a closed lifecycle. The depletion of the large number of small scallops in the Mid-Atlantic observed in 2003, and poor recruitment from 2009 to 2011, could lead to a rapid reduction in abundance, seriously impacting the fishery that was valued at US$455 million in 2010.
{"title":"Stock Definition and Recruitment: Implications for the U.S. Sea Scallop (Placopecten magellanicus) Fishery from 2003 to 2011","authors":"K. Stokesbury","doi":"10.1080/10641262.2012.695816","DOIUrl":"https://doi.org/10.1080/10641262.2012.695816","url":null,"abstract":"The United States sea scallop management plan applies fishing mortality in a uniform manner, assigning a single value of instantaneous fishing mortality (F) to the entire resource. Applying a single value of fishing mortality assumes the scallop resource is a single population. Dividing the resource into Georges Bank and Mid-Atlantic Bight reveals that each has been either excessively fished or underutilized based on the present definition of optimum yield. The sea scallop resource was highest in 2003 and has declined by about 50,000 metric tons, entirely from the Mid-Atlantic Bight. Abundance and the corresponding harvest levels will likely continue if the resource is a single population and scallops in the closed areas of Georges Bank populate the entire resource. Abundance and the corresponding harvest levels will likely decline if Georges Bank and the Mid-Atlantic Bight are separate populations in that scallops within these areas have a closed lifecycle. The depletion of the large number of small scallops in the Mid-Atlantic observed in 2003, and poor recruitment from 2009 to 2011, could lead to a rapid reduction in abundance, seriously impacting the fishery that was valued at US$455 million in 2010.","PeriodicalId":49627,"journal":{"name":"Reviews in Fisheries Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/10641262.2012.695816","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59680584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-06-18DOI: 10.1080/10641262.2012.683210
C. Edwards, R. Hillary, P. Levontin, J. L. Blanchard, K. Lorenzen
Deepwater fish populations are often characterized by their life-history as being highly susceptible to overexploitation. Moreover, dependent fisheries often develop rapidly, so overexploitation may occur before resource dynamics are quantified sufficiently to assess safe biological limits. It is therefore crucial to employ assessment methods that make the best use of limited data and management procedures that account for large uncertainties. This review provides a critical synthesis of assessment and management approaches for deepwater fisheries. Given limitations in the data, it is clear that assessments are likely to benefit from the application of derived relationships between life-history characteristics and the sharing of this and other information across stocks. It is important that uncertainty in assessment results is represented adequately, and management methods must in turn ensure that decision mechanisms are robust to an incomplete picture of resource dynamics. This requires construction and testing of harvest control rules within a simulation framework. Harvest control rules themselves, however, need not be complicated, and simple empirical approaches can be adequate for situations in which only relative changes in biomass can be discerned from the data. Development and testing of these control rules is likely to prove a productive area of future research.
{"title":"Fisheries Assessment and Management: A Synthesis of Common Approaches with Special Reference to Deepwater and Data-Poor Stocks","authors":"C. Edwards, R. Hillary, P. Levontin, J. L. Blanchard, K. Lorenzen","doi":"10.1080/10641262.2012.683210","DOIUrl":"https://doi.org/10.1080/10641262.2012.683210","url":null,"abstract":"Deepwater fish populations are often characterized by their life-history as being highly susceptible to overexploitation. Moreover, dependent fisheries often develop rapidly, so overexploitation may occur before resource dynamics are quantified sufficiently to assess safe biological limits. It is therefore crucial to employ assessment methods that make the best use of limited data and management procedures that account for large uncertainties. This review provides a critical synthesis of assessment and management approaches for deepwater fisheries. Given limitations in the data, it is clear that assessments are likely to benefit from the application of derived relationships between life-history characteristics and the sharing of this and other information across stocks. It is important that uncertainty in assessment results is represented adequately, and management methods must in turn ensure that decision mechanisms are robust to an incomplete picture of resource dynamics. This requires construction and testing of harvest control rules within a simulation framework. Harvest control rules themselves, however, need not be complicated, and simple empirical approaches can be adequate for situations in which only relative changes in biomass can be discerned from the data. Development and testing of these control rules is likely to prove a productive area of future research.","PeriodicalId":49627,"journal":{"name":"Reviews in Fisheries Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/10641262.2012.683210","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59680258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-05-31DOI: 10.1080/10641262.2012.689025
A. Stoner
Reducing animal stress and mortality associated with bycatch and discard in fishing, aquaculture, and live-market trade depends upon improvements in fishing gear and the practices employed in capture, holding, handling, and transport. Several approaches have been used to evaluate the likely mortality of commercially important crustaceans: (1) assess external injuries assuming a direct relationship to mortality, (2) extrapolate from direct observations of mortality under specific environmental conditions and handling practices, (3) evaluate the physiological condition of test animals to predict the associated mortality, and (4) assess behavioral indicators of vitality. Intrinsic variables, such as animal size, gender, and shell condition, and external variables, such as season, fishing and environmental conditions, and type of injury (physiological and mechanical), all have large effects on the complex interactions between stressors and mortality. This review shows that physiological parameters provide insight into the mechanisms of stress and stress responses, but they are often unrelated to mortality outcomes, and the methods are difficult and expensive to carry out in routine field or factory applications. In contrast, behavioral indicators, particularly those utilizing observations on multiple reflex actions, can provide excellent tools where predicting mortality is the primary goal.
{"title":"Assessing Stress and Predicting Mortality in Economically Significant Crustaceans","authors":"A. Stoner","doi":"10.1080/10641262.2012.689025","DOIUrl":"https://doi.org/10.1080/10641262.2012.689025","url":null,"abstract":"Reducing animal stress and mortality associated with bycatch and discard in fishing, aquaculture, and live-market trade depends upon improvements in fishing gear and the practices employed in capture, holding, handling, and transport. Several approaches have been used to evaluate the likely mortality of commercially important crustaceans: (1) assess external injuries assuming a direct relationship to mortality, (2) extrapolate from direct observations of mortality under specific environmental conditions and handling practices, (3) evaluate the physiological condition of test animals to predict the associated mortality, and (4) assess behavioral indicators of vitality. Intrinsic variables, such as animal size, gender, and shell condition, and external variables, such as season, fishing and environmental conditions, and type of injury (physiological and mechanical), all have large effects on the complex interactions between stressors and mortality. This review shows that physiological parameters provide insight into the mechanisms of stress and stress responses, but they are often unrelated to mortality outcomes, and the methods are difficult and expensive to carry out in routine field or factory applications. In contrast, behavioral indicators, particularly those utilizing observations on multiple reflex actions, can provide excellent tools where predicting mortality is the primary goal.","PeriodicalId":49627,"journal":{"name":"Reviews in Fisheries Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/10641262.2012.689025","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59680266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-03-23DOI: 10.1080/10641262.2012.663421
You‐Gan Wang, Na Wang
The appealing concept of optimal harvesting is often used in fisheries to obtain new management strategies. However, optimality depends on the objective function, which often varies, reflecting the interests of different groups of people. The aim of maximum sustainable yield is to extract the greatest amount of food from replenishable resources in a sustainable way. Maximum sustainable yield may not be desirable from an economic point of view. Maximum economic yield that maximizes the profit of fishing fleets (harvesting sector) but ignores socio-economic benefits such as employment and other positive externalities. It may be more appropriate to use the maximum economic yield that which is based on the value chain of the overall fishing sector, to reflect better society's interests. How to make more efficient use of a fishery for society rather than fishing operators depends critically on the gain function parameters including multiplier effects and inclusion or exclusion of certain costs. In particular, the optimal effort level based on the overall value chain moves closer to the optimal effort for the maximum sustainable yield because of the multiplier effect. These issues are illustrated using the Australian Northern Prawn Fishery.
{"title":"Implications of Gain Functions in Fisheries Management","authors":"You‐Gan Wang, Na Wang","doi":"10.1080/10641262.2012.663421","DOIUrl":"https://doi.org/10.1080/10641262.2012.663421","url":null,"abstract":"The appealing concept of optimal harvesting is often used in fisheries to obtain new management strategies. However, optimality depends on the objective function, which often varies, reflecting the interests of different groups of people. The aim of maximum sustainable yield is to extract the greatest amount of food from replenishable resources in a sustainable way. Maximum sustainable yield may not be desirable from an economic point of view. Maximum economic yield that maximizes the profit of fishing fleets (harvesting sector) but ignores socio-economic benefits such as employment and other positive externalities. It may be more appropriate to use the maximum economic yield that which is based on the value chain of the overall fishing sector, to reflect better society's interests. How to make more efficient use of a fishery for society rather than fishing operators depends critically on the gain function parameters including multiplier effects and inclusion or exclusion of certain costs. In particular, the optimal effort level based on the overall value chain moves closer to the optimal effort for the maximum sustainable yield because of the multiplier effect. These issues are illustrated using the Australian Northern Prawn Fishery.","PeriodicalId":49627,"journal":{"name":"Reviews in Fisheries Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/10641262.2012.663421","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59680253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-03-09DOI: 10.1080/10641262.2012.660999
M. Wuenschel, K. Able, J. Buckel, James W Morley, T. Lankford, A. Branson, D. Conover, Damien Drisco, A. Jordaan, K. Dunton, D. Secor, R. Woodland, F. Juanes, D. Stormer
Protracted spawning and pulsed juvenile production are common in coastal spawning fishes, the phenology of which determines potential environmental effects on recruitment. This article examines bluefish (Pomatomus saltatrix), a cosmopolitan coastal spawning species that produces multiple cohorts of juveniles utilizing both estuarine and coastal habitats as nurseries along the U.S. east coast. To determine recruitment on a coastwide basis, ocean (bottom, neuston, and surfzone) and estuarine habitats were sampled in Florida and North Carolina south of Cape Hatteras in the South Atlantic Bight, and Maryland, New Jersey, and New York in the Middle Atlantic Bight. This coordinated sampling effort across multiple habitats with multiple gears on a coastwide basis allowed the resolution of the occurrence, growth, and movement of cohorts along the coast. Production of the spring-spawned cohort occurred in both South Atlantic Bight and Middle Atlantic Bight habitats, while summer-spawned cohort production was limited to the Middle Atlantic Bight. Information from the present study is synthesized with prior research to develop a conceptual model of the seasonal patterns of YOY bluefish habitat use and to emphasize the value of coordinated sampling at a large spatial scale in understanding recruitment processes in this and potentially other important marine species.
{"title":"Recruitment Patterns and Habitat Use of Young-of-the-Year Bluefish along the United States East Coast: Insights from Coordinated Coastwide Sampling","authors":"M. Wuenschel, K. Able, J. Buckel, James W Morley, T. Lankford, A. Branson, D. Conover, Damien Drisco, A. Jordaan, K. Dunton, D. Secor, R. Woodland, F. Juanes, D. Stormer","doi":"10.1080/10641262.2012.660999","DOIUrl":"https://doi.org/10.1080/10641262.2012.660999","url":null,"abstract":"Protracted spawning and pulsed juvenile production are common in coastal spawning fishes, the phenology of which determines potential environmental effects on recruitment. This article examines bluefish (Pomatomus saltatrix), a cosmopolitan coastal spawning species that produces multiple cohorts of juveniles utilizing both estuarine and coastal habitats as nurseries along the U.S. east coast. To determine recruitment on a coastwide basis, ocean (bottom, neuston, and surfzone) and estuarine habitats were sampled in Florida and North Carolina south of Cape Hatteras in the South Atlantic Bight, and Maryland, New Jersey, and New York in the Middle Atlantic Bight. This coordinated sampling effort across multiple habitats with multiple gears on a coastwide basis allowed the resolution of the occurrence, growth, and movement of cohorts along the coast. Production of the spring-spawned cohort occurred in both South Atlantic Bight and Middle Atlantic Bight habitats, while summer-spawned cohort production was limited to the Middle Atlantic Bight. Information from the present study is synthesized with prior research to develop a conceptual model of the seasonal patterns of YOY bluefish habitat use and to emphasize the value of coordinated sampling at a large spatial scale in understanding recruitment processes in this and potentially other important marine species.","PeriodicalId":49627,"journal":{"name":"Reviews in Fisheries Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/10641262.2012.660999","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59680197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-03-09DOI: 10.1080/10641262.2012.659775
I. Jarić, G. Cvijanovic, Jelena Knezevic-Jaric, M. Lenhardt
The present study applies a bibliometric approach to identify recent patterns and trends in the methods, subjects, and authorships in the literature published in fisheries science (2000–2009). The results indicate that the most frequently studied group of species were Salmonidae, although the interest for these species seems to be diminishing. The studies of the marine habitat and inland habitats, respectively, have revealed a marked increase and decrease in frequency. Genetics represents the most rapidly growing area of research. The model development was the most frequently applied method in fisheries science, although such publications have had a generally lower number of citations. The number of experimental studies was markedly low, but they were also the most frequently cited. The United States was the most productive country over the last decade with a gradually increasing output over the time, but it was surpassed by the total European Union output. An apparent difference in the research output has been recorded between the developed and developing countries. The findings of this study, however, indicate a positive tendency in this direction. A growing rate of publications based on international collaboration was recorded, and such publications also demonstrate a higher number of citations than the single-country publications.
{"title":"Trends in Fisheries Science from 2000 to 2009: A Bibliometric Study","authors":"I. Jarić, G. Cvijanovic, Jelena Knezevic-Jaric, M. Lenhardt","doi":"10.1080/10641262.2012.659775","DOIUrl":"https://doi.org/10.1080/10641262.2012.659775","url":null,"abstract":"The present study applies a bibliometric approach to identify recent patterns and trends in the methods, subjects, and authorships in the literature published in fisheries science (2000–2009). The results indicate that the most frequently studied group of species were Salmonidae, although the interest for these species seems to be diminishing. The studies of the marine habitat and inland habitats, respectively, have revealed a marked increase and decrease in frequency. Genetics represents the most rapidly growing area of research. The model development was the most frequently applied method in fisheries science, although such publications have had a generally lower number of citations. The number of experimental studies was markedly low, but they were also the most frequently cited. The United States was the most productive country over the last decade with a gradually increasing output over the time, but it was surpassed by the total European Union output. An apparent difference in the research output has been recorded between the developed and developing countries. The findings of this study, however, indicate a positive tendency in this direction. A growing rate of publications based on international collaboration was recorded, and such publications also demonstrate a higher number of citations than the single-country publications.","PeriodicalId":49627,"journal":{"name":"Reviews in Fisheries Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/10641262.2012.659775","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59680149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-02-24DOI: 10.1080/10641262.2011.654287
Sarah M. Martin, Tracy A. Cambridge, C. Grieve, F. Nimmo, D. Agnew
There is ongoing debate regarding the value of market-based instruments, such as certification schemes, as an approach to improving the environmental impact of fisheries. This article evaluates the effects of the Marine Stewardship Council on the environmental performance of fisheries over the period before and after certification. A large number of fisheries (n = 447) have undertaken pre-assessments, and in most cases (83%), the auditors recommended that significant improvements should be made before entering full assessment. In cases where substantial improvements were required, the proportion of performance indicators scoring over 80 (considered by the Marine Stewardship Council to be the point of best practice) increased by 22% between pre-assessment and certification. Significant improvements continued after certification, characterized by a 16% increase in the proportion of performance indicators scoring over 80 over a period of five years. Increases in scores assigned by auditors were significantly correlated with increases in real environmental performance (such as increases in stock biomass or the development of protected areas) and improvements in information, which led to increasing certainty that impacts were within sustainable limits. Although results show that certification is associated with real environmental benefits, most improvements are made by fisheries that require significant changes to enter the program. [Supplementary materials are available for this article. Go to the publisher's online edition of Reviews in Fisheries Science for the following free supplemental resources: information and references used in order to analyze the trends related to each fishery performance indicator]
{"title":"An Evaluation of Environmental Changes Within Fisheries Involved in the Marine Stewardship Council Certification Scheme","authors":"Sarah M. Martin, Tracy A. Cambridge, C. Grieve, F. Nimmo, D. Agnew","doi":"10.1080/10641262.2011.654287","DOIUrl":"https://doi.org/10.1080/10641262.2011.654287","url":null,"abstract":"There is ongoing debate regarding the value of market-based instruments, such as certification schemes, as an approach to improving the environmental impact of fisheries. This article evaluates the effects of the Marine Stewardship Council on the environmental performance of fisheries over the period before and after certification. A large number of fisheries (n = 447) have undertaken pre-assessments, and in most cases (83%), the auditors recommended that significant improvements should be made before entering full assessment. In cases where substantial improvements were required, the proportion of performance indicators scoring over 80 (considered by the Marine Stewardship Council to be the point of best practice) increased by 22% between pre-assessment and certification. Significant improvements continued after certification, characterized by a 16% increase in the proportion of performance indicators scoring over 80 over a period of five years. Increases in scores assigned by auditors were significantly correlated with increases in real environmental performance (such as increases in stock biomass or the development of protected areas) and improvements in information, which led to increasing certainty that impacts were within sustainable limits. Although results show that certification is associated with real environmental benefits, most improvements are made by fisheries that require significant changes to enter the program. [Supplementary materials are available for this article. Go to the publisher's online edition of Reviews in Fisheries Science for the following free supplemental resources: information and references used in order to analyze the trends related to each fishery performance indicator]","PeriodicalId":49627,"journal":{"name":"Reviews in Fisheries Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/10641262.2011.654287","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59680134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-01-01DOI: 10.1080/10641262.2011.643697
E. L. Brannon, K. Collins, M. Cronin, L. Moulton, A. Maki, K. Parker
The Exxon Valdez oil spill that occurred in Prince William Sound, Alaska, in March of 1989 was the largest crude oil spill in the United States at that time, and it was anticipated to have disastrous effects on the ecology and fisheries of that coastal region. The large pink salmon returns to the sound, a major commercial species in Alaska, were of great concern. The Exxon Valdez Oil Spill Trustee Council, a council of government agencies formed to assess the impact of the spill for recovery purposes, concluded that pink salmon in Prince William Sound were damaged by the oil, based on investigations of the Alaska Department of Fish and Game and the National Marine Fisheries Service. Agency scientists claimed that the oil increased incubation mortality of pink salmon and those exposed to oil experienced less growth, higher long-term mortality, and reduced reproductive success. This contrasted with data and conclusions of the non-agency scientists led by the University of Idaho researchers that showed no impact of oil on incubating eggs or on juvenile pink salmon in marine waters, and no reduction in egg viability of returning adults. In this article the authors re-examine the evidence and resolve the problems that resulted in the different interpretation of research conducted by agency and non-agency scientists. The resolution has far reaching implications on ascertaining the impacts of marine oil spills.
{"title":"Review of the Exxon Valdez Oil Spill Effects on Pink Salmon in Prince William Sound, Alaska","authors":"E. L. Brannon, K. Collins, M. Cronin, L. Moulton, A. Maki, K. Parker","doi":"10.1080/10641262.2011.643697","DOIUrl":"https://doi.org/10.1080/10641262.2011.643697","url":null,"abstract":"The Exxon Valdez oil spill that occurred in Prince William Sound, Alaska, in March of 1989 was the largest crude oil spill in the United States at that time, and it was anticipated to have disastrous effects on the ecology and fisheries of that coastal region. The large pink salmon returns to the sound, a major commercial species in Alaska, were of great concern. The Exxon Valdez Oil Spill Trustee Council, a council of government agencies formed to assess the impact of the spill for recovery purposes, concluded that pink salmon in Prince William Sound were damaged by the oil, based on investigations of the Alaska Department of Fish and Game and the National Marine Fisheries Service. Agency scientists claimed that the oil increased incubation mortality of pink salmon and those exposed to oil experienced less growth, higher long-term mortality, and reduced reproductive success. This contrasted with data and conclusions of the non-agency scientists led by the University of Idaho researchers that showed no impact of oil on incubating eggs or on juvenile pink salmon in marine waters, and no reduction in egg viability of returning adults. In this article the authors re-examine the evidence and resolve the problems that resulted in the different interpretation of research conducted by agency and non-agency scientists. The resolution has far reaching implications on ascertaining the impacts of marine oil spills.","PeriodicalId":49627,"journal":{"name":"Reviews in Fisheries Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/10641262.2011.643697","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59680088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-01-01DOI: 10.1080/10641262.2011.634930
W. J. Miller, B. Manly, D. Murphy, D. Fullerton, R. R. Ramey
The delta smelt is an annual fish that is endemic to the Sacramento-San Joaquin Estuary and is protected under federal and California Endangered Species Acts. Record low abundances have occurred since 2004. Three questions are addressed here: What is the relative importance of environmental factors with direct effects on abundance? Do factors that may have indirect effects provide an explanation of abundance changes? Are effects of environmental factors better accounted for individually or as criteria defining the volume of water with suitable abiotic attributes? Strong evidence was found of density-dependent population regulation. The density of prey was the most important environmental factor explaining variations in delta smelt abundance from 1972 to 2006 and over the recent period of decline in the abundance of the fish. Predation and water temperature showed possible effects. Entrainment of delta smelt at south Delta pumping plants showed statistically significant effects on adult-to-juvenile survival but not over the fish's life cycle. Neither the volume of water with suitable abiotic attributes nor other factors with indirect effects, including the location of the 2 ppt isohaline in the Delta in the previous fall (“fall X2”), explained delta smelt population trends beyond those accounted for by prey density. [Supplementary materials are available for this article. Go to the publisher's online edition of Reviews in Fisheries Science for the following free supplemental resources: information on factor selection and specification; and estimating the volume of abiotic habitat.]
{"title":"An Investigation of Factors Affecting the Decline of Delta Smelt (Hypomesus transpacificus) in the Sacramento-San Joaquin Estuary","authors":"W. J. Miller, B. Manly, D. Murphy, D. Fullerton, R. R. Ramey","doi":"10.1080/10641262.2011.634930","DOIUrl":"https://doi.org/10.1080/10641262.2011.634930","url":null,"abstract":"The delta smelt is an annual fish that is endemic to the Sacramento-San Joaquin Estuary and is protected under federal and California Endangered Species Acts. Record low abundances have occurred since 2004. Three questions are addressed here: What is the relative importance of environmental factors with direct effects on abundance? Do factors that may have indirect effects provide an explanation of abundance changes? Are effects of environmental factors better accounted for individually or as criteria defining the volume of water with suitable abiotic attributes? Strong evidence was found of density-dependent population regulation. The density of prey was the most important environmental factor explaining variations in delta smelt abundance from 1972 to 2006 and over the recent period of decline in the abundance of the fish. Predation and water temperature showed possible effects. Entrainment of delta smelt at south Delta pumping plants showed statistically significant effects on adult-to-juvenile survival but not over the fish's life cycle. Neither the volume of water with suitable abiotic attributes nor other factors with indirect effects, including the location of the 2 ppt isohaline in the Delta in the previous fall (“fall X2”), explained delta smelt population trends beyond those accounted for by prey density. [Supplementary materials are available for this article. Go to the publisher's online edition of Reviews in Fisheries Science for the following free supplemental resources: information on factor selection and specification; and estimating the volume of abiotic habitat.]","PeriodicalId":49627,"journal":{"name":"Reviews in Fisheries Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/10641262.2011.634930","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59680056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-10-01DOI: 10.1080/10641262.2011.611916
P. Glibert, D. Fullerton, J. Burkholder, J. Cornwell, T. Kana
Eutrophication has altered food webs across aquatic systems, but effects of nutrient stoichiometry (varying nutrient ratios) on ecosystem structure and function have received less attention. A prevailing assumption has been that nutrients are not ecologically relevant unless concentrations are limiting to phytoplankton. However, changes in nutrient stoichiometry fundamentally affect food quality at all levels of the food web. Here, 30-year records of nitrogen and phosphorus concentrations and ratios, phytoplankton, zooplankton, macroinvertebrates, and fish in the San Francisco Estuary (Bay Delta) were examined to collectively interpret ecosystem changes within the framework of ecological stoichiometry. Changes in nutrient concentrations and nutrient ratios over time fundamentally affect biogeochemical nutrient dynamics that can lead to conditions conducive to invasions of rooted macrophytes and bivalve molluscs, and the harmful cyanobacterium Microcystis. Several other aquatic ecosystems considered here have exhibited similar changes in food webs linked to stoichiometric changes. Nutrient stoichiometry is thus suggested to be a significant driver of food webs in the Bay Delta by altering food quality and biogeochemical dynamics. Since nitrogen-to-phosphorus ratios have increased over time, an overall implication is that remediation of fish populations in the San Francisco Estuary will require significant nitrogen reductions to restore the historic ecological stoichiometric balance and the food web.
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