This series is a secondary scientific series designed to assure the long-term documentation and t... more This series is a secondary scientific series designed to assure the long-term documentation and to enable the timely transmission of research results by Center and/or non-Center researchers, where such results bear upon the research mission of the Center (see the outside back cover for the mission statement). These documents receive internal scientific review, and most receive copy editing. The National Marine Fisheries Service does not endorse any proprietary material, process, or product mentioned in these documents. All documents issued in this series since April 2001, and several documents issued prior to that date, have been copublished in both paper and electronic versions. To access the electronic version of a document in this series, go to http://www.nefsc.noaa.gov/nefsc/publications/. The electronic version is available in PDF format to permit printing of a paper copy directly from the Internet. If you do not have Internet access, or if a desired document is one of the pre-April 2001 documents available only in the paper version, you can obtain a paper copy by contacting the senior Center author of the desired document. Refer to the title page of the document for the senior Center author's name and mailing address. If there is no Center author, or if there is corporate (i.e., non-individualized) authorship, then contact the Center's Woods Hole Laboratory Library (166 Water St., Woods Hole, MA 02543-1026). Editorial Treatment: To distribute this report quickly, it has not undergone the normal technical and copy editing by the Northeast Fisheries Science Center's (NEFSC's) Editorial Office as have most other issues in the NOAA Technical Memorandum NMFS-NE series. Other than the four covers and first two preliminary pages, all writing and editing have been performed by the authors listed within.
Reviews in Fish Biology and Fisheries, Mar 13, 2011
The summer flounder, or fluke, Paralichthys dentatus, supports the most important commercial and ... more The summer flounder, or fluke, Paralichthys dentatus, supports the most important commercial and recreational flatfish fisheries of the US Atlantic coast. The stock and fishery range from Massachusetts to North Carolina. The assessment and management of the summer flounder fishery has been very contentious since implementation of the joint Atlantic States Marine Fisheries Commission/Mid-Atlantic Fishery Management Council Fishery Management Plan (FMP) in 1989, when the poor status of the summer flounder stock was evident to scientists, managers, and fishermen. Management efforts to control fishing mortality in the face of increasing stock abundance and competing demand for fish from both the commercial and recreational sectors continue to evoke the question of ''How much fish is enough?'' to provide for long-term sustainability. In spite of the numerous controversies, however, by 2010 the fishing mortality on summer flounder had declined to its lowest level in at least 30 years, and summer flounder stock biomass was the highest since the stock assessments began in the 1960s. From a scientific perspective, future assessments need to: (a) better account for the uncertainty resulting from ''internal model'' retrospective error, (b) better integrate environmental, ecological, and other nontraditional calibration indices into the modeling framework, and (c) better discern summer flounder stock-recruitment dynamics by considering covariates such as environmental factors and predator/prey abundance. Initiatives are underway to acquire improved fishery and biological data to allow the assessments to better reflect the true ''state of nature.'' Keywords Summer flounder Á Fisheries Á Assessment Á Management There was always a minority afraid of something, and a great majority afraid of the dark, afraid of the future, afraid of the past, afraid of the present, afraid of themselves and shadows of themselves. from ''Usher II'' in The Martian Chronicles by Ray Bradbury (1997).
USA Commercial landings of cod, haddock, and yellowtail flounder were prorated using vessel trip ... more USA Commercial landings of cod, haddock, and yellowtail flounder were prorated using vessel trip report information, collected under the regional mandatory reporting system, to determine stock area landings for 1994, 1995 and 1996. Stock area landings in 1994, 1995 and 1996 are as follows: Gulf of Maine cod: 7877 mt, 6798 mt and 7194 mt, respectively; Georges Bank cod: 9893 mt, 6759 mt and 7020 mt, respectively; Georges Bank haddock: 218 mt, 218 mt and 313 mt, respectively; Georges Bank yellowtail flounder: 1588 mt, 292 mt, and 751 mt, respectively; and Southern New England yellowtail flounder: 225 mt, 187 mt, and 285 mt, respectively. These stock area landings are provisional pending a more complete audit of the vessel trip report data and until all of the 1996 landings data have been collected and finalized.
This series is a secondary scientific series designed to assure the long-term documentation and t... more This series is a secondary scientific series designed to assure the long-term documentation and to enable the timely transmission of research results by Center and/or non-Center researchers, where such results bear upon the research mission of the Center (see the outside back cover for the mission statement). These documents receive internal scientific review, and most receive copy editing. The National Marine Fisheries Service does not endorse any proprietary material, process, or product mentioned in these documents. All documents issued in this series since April 2001, and several documents issued prior to that date, have been copublished in both paper and electronic versions. To access the electronic version of a document in this series, go to http://www.nefsc.noaa.gov/nefsc/publications/. The electronic version is available in PDF format to permit printing of a paper copy directly from the Internet. If you do not have Internet access, or if a desired document is one of the pre-April 2001 documents available only in the paper version, you can obtain a paper copy by contacting the senior Center author of the desired document. Refer to the title page of the document for the senior Center author's name and mailing address. If there is no Center author, or if there is corporate (i.e., non-individualized) authorship, then contact the Center's Woods Hole Laboratory Library (166 Water St., Woods Hole, MA 02543-1026). Editorial Treatment: To distribute this report quickly, it has not undergone the normal technical and copy editing by the Northeast Fisheries Science Center's (NEFSC's) Editorial Office as have most other issues in the NOAA Technical Memorandum NMFS-NE series. Other than the four covers and first two preliminary pages, all writing and editing have been performed by the authors listed within.
Transactions of The American Fisheries Society, Sep 1, 1992
We simulated length-frequency distributions for 3-, 7-, and 13-age-class exploited populations to... more We simulated length-frequency distributions for 3-, 7-, and 13-age-class exploited populations to compare the performance of Shepherd's length composition analysis (SRLCA) and MULTIFAN in resolving the distributions to age frequencies. The length distributions were characterized by von Bertalanffy growth, variable recruitment, variable mortality, partial selectivity of fishing gear for the youngest age-groups, and a length-dependent trend in the standard deviation
This series is a secondary scientific series designed to assure the long-term documentation and t... more This series is a secondary scientific series designed to assure the long-term documentation and to enable the timely transmission of research results by Center and/or non-Center researchers, where such results bear upon the research mission of the Center (see the outside back cover for the mission statement). These documents receive internal scientific review, and most receive copy editing. The National Marine Fisheries Service does not endorse any proprietary material, process, or product mentioned in these documents. All documents issued in this series since April 2001, and several documents issued prior to that date, have been copublished in both paper and electronic versions. To access the electronic version of a document in this series, go to http://www.nefsc.noaa.gov/nefsc/publications/. The electronic version is available in PDF format to permit printing of a paper copy directly from the Internet. If you do not have Internet access, or if a desired document is one of the pre-April 2001 documents available only in the paper version, you can obtain a paper copy by contacting the senior Center author of the desired document. Refer to the title page of the document for the senior Center author's name and mailing address. If there is no Center author, or if there is corporate (i.e., non-individualized) authorship, then contact the Center's Woods Hole Laboratory Library (166 Water St., Woods Hole, MA 02543-1026). Editorial Treatment: To distribute this report quickly, it has not undergone the normal technical and copy editing by the Northeast Fisheries Science Center's (NEFSC's) Editorial Office as have most other issues in the NOAA Technical Memorandum NMFS-NE series. Other than the four covers and first two preliminary pages, all writing and editing have been performed by the authors listed within.
Although the contents have not been copyrighted and may be reprinted entirely, reference to the s... more Although the contents have not been copyrighted and may be reprinted entirely, reference to the source is appreciated.
Winter flounder Pseudopleuronectes arnericanus in Narragansett Bay, Rhode Island, reached peak ab... more Winter flounder Pseudopleuronectes arnericanus in Narragansett Bay, Rhode Island, reached peak abundance in 1968 and then went into an 8 yr decline, dropping to ' 1 7 of its former population size, as estimated from weekly tows by otter trawl. Meanwhile a succession of species increased offshore: red hake Urophycis chuss became the commercial dominant in 1973, the ocean pout Macrozoarces arnericanus and silver hake Merluccius bilinearis in 1974, but among these coastal migrants only scup Stenotomus chrysops entered the bay in substantial numbers. By 1976 scup had increased 25 times in the bay, numerically overshadowing the flounder's 8 yr decline. A year later, flounder began to recover; and after 3 yr (1979) it had achieved its former abundance, only to decrease 58% over the next 3 yr (1982). Throughout the entire sampling period, migrants and residents bore close inverse relations in bay and sound. Thus, when the bay's flounder population dropped to '/3 of its 1968 maximum, migrants dominated the sound's fishes, possibly having been attracted to the immediate area by foods not utilized by the dwindling flounder population during its spring-fall migration from estuarine to coastal waters. These patterns appeared to be initiated by warming and cooling trends so subtle that the effect may have been mediated by predation on larvae at metamorphosis, a process eventually influencing the entire complex of benthic fishes in the Narragansett Bay area.
Canadian Journal of Fisheries and Aquatic Sciences, Apr 1, 1991
We present an extension of the MULTIFAN method for simultaneously analyzing several length freque... more We present an extension of the MULTIFAN method for simultaneously analyzing several length frequency data sets from length frequency data collected by research trawl surveys. The assumption that the research trawl samples the animals in a regular fashion allows the proportions at age in the samples to be parameterized in terms of relative year class strengths and the age-dependent selectivity of the sampling procedure. When available, relative abundance data can be incorporated into the analysis and permit the estimation of mortality. The method is applied to Gulf of Maine northern shrimp (Pandalus borealis) data. The parameter estimates obtained agree substantially with those previously obtained using a more detailed knowledge of the species' biology.
Scup 293 Executive Summary The current biomass reference point for scup relies on the index of Sp... more Scup 293 Executive Summary The current biomass reference point for scup relies on the index of Spawning Stock Biomass (SSB) from the NEFSC spring trawl survey. Previous reviews of the stock assessment have indicated that while this index may be the most reliable fishery independent index of scup SSB, it is subject to a relatively high degree of inter-annual variability that reduces its utility as an indicator of stock status. Managers, scientists, and other stakeholders indicated a desire for a more reliable way to monitor the status of scup and support the annual specification of fishery regulations. The December 2008 Northeast Data Poor Stocks Peer Review Panel accepted a revised stock assessment using a statistical catch at age model (ASAP) as the basis for biological reference points and status determination for scup. The new model of scup population dynamics and the recommended reference points represent a more stable approach for monitoring stock status and specifying annual fishery regulations, compared with the current single index-based model. The new model integrates a broad array of fishery and survey input data and should be less sensitive to inter-annual changes in any single data component than the current model. The Peer Review Panel recommended F 40% as the proxy for F MSY , and the corresponding SSB F40% as the proxy for SSB MSY. The F 40% proxy for F MSY = 0.177, the proxy estimate for SSB MSY = 92,044 mt, and the proxy estimate for MSY = 16,161 mt (13,134 mt of landings, 3,027 mt of discards). The stock biomass threshold of ½ SSB MSY = ½ SSB F40% = 46,022 mt = 101.461 million lbs. The 2007 SSB estimate of 119,343 mt is 30% above SSB MSY = 92,044 mt, indicating the stock was not overfished. The F 2007 estimate of 0.054 is 31% of F MSY = 0.177, indicating overfishing was not occurring. Total catch (landings plus discards) was 7,867 mt in 2007, about 49% of MSY. The revised status determination represents a significant change from the recent biomass status update conducted in July 2008, which indicated that the stock was overfished in 2007, although not experiencing overfishing. While the accepted long-term MSY estimate appears feasible given historical evidence from the fishery, managers may wish to take an adaptive approach to the specification of fishery quotas in the short-term. Total fishery landings over the last five years (2003-2007) have averaged …
Summary There is currently no generally agreed methodological approach to adjusting projections t... more Summary There is currently no generally agreed methodological approach to adjusting projections to account for retrospective patterns in the stock assessment. This paper presents three alternative approaches and compares the resulting time series of spawning stock biomass, landings, and fishing mortality rate based on a summer flounder-like stock assessment. The three adjustments for retrospective patterns all reduce landings in the quota setting year, but the magnitude of the reduction is quite variable and the implications for future years in the projections are quite different. Adjusting the fishing mortality rate in the quota setting year is not recommended in the context of rebuilding programs because the future catches are greater than the unadjusted projections. Adjusting all ages in the starting population creates the largest decrease in projected catch, but typically cannot be justified based on the patterns observed at age. Making adjustments to the starting population based on the age specific retrospective patterns produces the most consistent approach, although the overall impact is relatively minor. A number of technical questions remain regarding exactly how to compute the retrospective adjustments at age. Management strategy evaluation work is required in the future to determine if any adjustment method performs better than the others.
This series is a secondary scientific series designed to assure the long-term documentation and t... more This series is a secondary scientific series designed to assure the long-term documentation and to enable the timely transmission of research results by Center and/or non-Center researchers, where such results bear upon the research mission of the Center (see the outside back cover for the mission statement). These documents receive internal scientific review, and most receive copy editing. The National Marine Fisheries Service does not endorse any proprietary material, process, or product mentioned in these documents. All documents issued in this series since April 2001, and several documents issued prior to that date, have been copublished in both paper and electronic versions. To access the electronic version of a document in this series, go to http://www.nefsc.noaa.gov/nefsc/publications/. The electronic version is available in PDF format to permit printing of a paper copy directly from the Internet. If you do not have Internet access, or if a desired document is one of the pre-April Editorial Treatment: To distribute this report quickly, it has not undergone the normal technical and copy editing by the Northeast Fisheries Science Center's (NEFSC's) Editorial Office as have most other issues in the NOAA Technical Memorandum NMFS-NE series. Other than the four covers and first two preliminary pages, all writing and editing have been performed by the authors listed within. Information Quality Act Compliance: In accordance with section 515 of Public Law 106-554, the Northeast Fisheries Science Center completed both technical and policy reviews for this report. These predissemination reviews are on file at the NEFSC Editorial Office. This assessment of the scup (Stenotomus chrysops) stock along the Atlantic coast (Massachusetts to North Carolina) is an update through 2011 of commercial and recreational fishery (MRIP) catch data, research survey indices of abundance, and the analyses of those data. The stock was not overfished and overfishing was not occurring in 2011 relative to the biological reference points established in the 2008 Northeast Data Poor Stocks (DPS) assessment. The fishing mortality rate (F) was estimated to be 0.034 in 2011, below the fishing mortality threshold reference point = Fishing mortality producing Maximum Sustainable Yield (FMSY) = F40% = 0.177. Spawning Stock Biomass (SSB) was estimated to be 190,424 metric tons (mt) = 420 million lbs in 2011, above the biomass target reference point = SSBMSY = SSB40% = 92,044 mt = 203 million lbs. recruitment estimates are influenced mainly by the assessment model stock-recruitment relationship. Since 1984, recruitment estimates from …
This series is a secondary scientific series designed to assure the long-term documentation and t... more This series is a secondary scientific series designed to assure the long-term documentation and to enable the timely transmission of research results by Center and/or non-Center researchers, where such results bear upon the research mission of the Center (see the outside back cover for the mission statement). These documents receive internal scientific review, and most receive copy editing. The National Marine Fisheries Service does not endorse any proprietary material, process, or product mentioned in these documents. All documents issued in this series since April 2001, and several documents issued prior to that date, have been copublished in both paper and electronic versions. To access the electronic version of a document in this series, go to http://www.nefsc.noaa.gov/nefsc/publications/. The electronic version is available in PDF format to permit printing of a paper copy directly from the Internet. If you do not have Internet access, or if a desired document is one of the pre-April 2001 documents available only in the paper version, you can obtain a paper copy by contacting the senior Center author of the desired document. Refer to the title page of the document for the senior Center author's name and mailing address. If there is no Center author, or if there is corporate (i.e., non-individualized) authorship, then contact the Center's Woods Hole Laboratory Library (166 Water St., Woods Hole, MA 02543-1026). Editorial Treatment: To distribute this report quickly, it has not undergone the normal technical and copy editing by the Northeast Fisheries Science Center's (NEFSC's) Editorial Office as have most other issues in the NOAA Technical Memorandum NMFS-NE series. Other than the four covers and first two preliminary pages, all writing and editing have been performed by the authors listed within.
Reviews in Fish Biology and Fisheries, Mar 13, 2011
The summer flounder, or fluke, Paralichthys dentatus, supports the most important commercial and ... more The summer flounder, or fluke, Paralichthys dentatus, supports the most important commercial and recreational flatfish fisheries of the US Atlantic coast. The stock and fishery range from Massachusetts to North Carolina. The assessment and management of the summer flounder fishery has been very contentious since implementation of the joint Atlantic States Marine Fisheries Commission/Mid-Atlantic Fishery Management Council Fishery Management Plan (FMP) in 1989, when the poor status of the summer flounder stock was evident to scientists, managers, and fishermen. Management efforts to control fishing mortality in the face of increasing stock abundance and competing demand for fish from both the commercial and recreational sectors continue to evoke the question of ''How much fish is enough?'' to provide for long-term sustainability. In spite of the numerous controversies, however, by 2010 the fishing mortality on summer flounder had declined to its lowest level in at least 30 years, and summer flounder stock biomass was the highest since the stock assessments began in the 1960s. From a scientific perspective, future assessments need to: (a) better account for the uncertainty resulting from ''internal model'' retrospective error, (b) better integrate environmental, ecological, and other nontraditional calibration indices into the modeling framework, and (c) better discern summer flounder stock-recruitment dynamics by considering covariates such as environmental factors and predator/prey abundance. Initiatives are underway to acquire improved fishery and biological data to allow the assessments to better reflect the true ''state of nature.'' Keywords Summer flounder Á Fisheries Á Assessment Á Management There was always a minority afraid of something, and a great majority afraid of the dark, afraid of the future, afraid of the past, afraid of the present, afraid of themselves and shadows of themselves. from ''Usher II'' in The Martian Chronicles by Ray Bradbury (1997).
USA Commercial landings of cod, haddock, and yellowtail flounder were prorated using vessel trip ... more USA Commercial landings of cod, haddock, and yellowtail flounder were prorated using vessel trip report information, collected under the regional mandatory reporting system, to determine stock area landings for 1994, 1995 and 1996. Stock area landings in 1994, 1995 and 1996 are as follows: Gulf of Maine cod: 7877 mt, 6798 mt and 7194 mt, respectively; Georges Bank cod: 9893 mt, 6759 mt and 7020 mt, respectively; Georges Bank haddock: 218 mt, 218 mt and 313 mt, respectively; Georges Bank yellowtail flounder: 1588 mt, 292 mt, and 751 mt, respectively; and Southern New England yellowtail flounder: 225 mt, 187 mt, and 285 mt, respectively. These stock area landings are provisional pending a more complete audit of the vessel trip report data and until all of the 1996 landings data have been collected and finalized.
This series is a secondary scientific series designed to assure the long-term documentation and t... more This series is a secondary scientific series designed to assure the long-term documentation and to enable the timely transmission of research results by Center and/or non-Center researchers, where such results bear upon the research mission of the Center (see the outside back cover for the mission statement). These documents receive internal scientific review, and most receive copy editing. The National Marine Fisheries Service does not endorse any proprietary material, process, or product mentioned in these documents. All documents issued in this series since April 2001, and several documents issued prior to that date, have been copublished in both paper and electronic versions. To access the electronic version of a document in this series, go to http://www.nefsc.noaa.gov/nefsc/publications/. The electronic version is available in PDF format to permit printing of a paper copy directly from the Internet. If you do not have Internet access, or if a desired document is one of the pre-April 2001 documents available only in the paper version, you can obtain a paper copy by contacting the senior Center author of the desired document. Refer to the title page of the document for the senior Center author's name and mailing address. If there is no Center author, or if there is corporate (i.e., non-individualized) authorship, then contact the Center's Woods Hole Laboratory Library (166 Water St., Woods Hole, MA 02543-1026). Editorial Treatment: To distribute this report quickly, it has not undergone the normal technical and copy editing by the Northeast Fisheries Science Center's (NEFSC's) Editorial Office as have most other issues in the NOAA Technical Memorandum NMFS-NE series. Other than the four covers and first two preliminary pages, all writing and editing have been performed by the authors listed within.
Transactions of The American Fisheries Society, Sep 1, 1992
We simulated length-frequency distributions for 3-, 7-, and 13-age-class exploited populations to... more We simulated length-frequency distributions for 3-, 7-, and 13-age-class exploited populations to compare the performance of Shepherd's length composition analysis (SRLCA) and MULTIFAN in resolving the distributions to age frequencies. The length distributions were characterized by von Bertalanffy growth, variable recruitment, variable mortality, partial selectivity of fishing gear for the youngest age-groups, and a length-dependent trend in the standard deviation
This series is a secondary scientific series designed to assure the long-term documentation and t... more This series is a secondary scientific series designed to assure the long-term documentation and to enable the timely transmission of research results by Center and/or non-Center researchers, where such results bear upon the research mission of the Center (see the outside back cover for the mission statement). These documents receive internal scientific review, and most receive copy editing. The National Marine Fisheries Service does not endorse any proprietary material, process, or product mentioned in these documents. All documents issued in this series since April 2001, and several documents issued prior to that date, have been copublished in both paper and electronic versions. To access the electronic version of a document in this series, go to http://www.nefsc.noaa.gov/nefsc/publications/. The electronic version is available in PDF format to permit printing of a paper copy directly from the Internet. If you do not have Internet access, or if a desired document is one of the pre-April 2001 documents available only in the paper version, you can obtain a paper copy by contacting the senior Center author of the desired document. Refer to the title page of the document for the senior Center author's name and mailing address. If there is no Center author, or if there is corporate (i.e., non-individualized) authorship, then contact the Center's Woods Hole Laboratory Library (166 Water St., Woods Hole, MA 02543-1026). Editorial Treatment: To distribute this report quickly, it has not undergone the normal technical and copy editing by the Northeast Fisheries Science Center's (NEFSC's) Editorial Office as have most other issues in the NOAA Technical Memorandum NMFS-NE series. Other than the four covers and first two preliminary pages, all writing and editing have been performed by the authors listed within.
Although the contents have not been copyrighted and may be reprinted entirely, reference to the s... more Although the contents have not been copyrighted and may be reprinted entirely, reference to the source is appreciated.
Winter flounder Pseudopleuronectes arnericanus in Narragansett Bay, Rhode Island, reached peak ab... more Winter flounder Pseudopleuronectes arnericanus in Narragansett Bay, Rhode Island, reached peak abundance in 1968 and then went into an 8 yr decline, dropping to ' 1 7 of its former population size, as estimated from weekly tows by otter trawl. Meanwhile a succession of species increased offshore: red hake Urophycis chuss became the commercial dominant in 1973, the ocean pout Macrozoarces arnericanus and silver hake Merluccius bilinearis in 1974, but among these coastal migrants only scup Stenotomus chrysops entered the bay in substantial numbers. By 1976 scup had increased 25 times in the bay, numerically overshadowing the flounder's 8 yr decline. A year later, flounder began to recover; and after 3 yr (1979) it had achieved its former abundance, only to decrease 58% over the next 3 yr (1982). Throughout the entire sampling period, migrants and residents bore close inverse relations in bay and sound. Thus, when the bay's flounder population dropped to '/3 of its 1968 maximum, migrants dominated the sound's fishes, possibly having been attracted to the immediate area by foods not utilized by the dwindling flounder population during its spring-fall migration from estuarine to coastal waters. These patterns appeared to be initiated by warming and cooling trends so subtle that the effect may have been mediated by predation on larvae at metamorphosis, a process eventually influencing the entire complex of benthic fishes in the Narragansett Bay area.
Canadian Journal of Fisheries and Aquatic Sciences, Apr 1, 1991
We present an extension of the MULTIFAN method for simultaneously analyzing several length freque... more We present an extension of the MULTIFAN method for simultaneously analyzing several length frequency data sets from length frequency data collected by research trawl surveys. The assumption that the research trawl samples the animals in a regular fashion allows the proportions at age in the samples to be parameterized in terms of relative year class strengths and the age-dependent selectivity of the sampling procedure. When available, relative abundance data can be incorporated into the analysis and permit the estimation of mortality. The method is applied to Gulf of Maine northern shrimp (Pandalus borealis) data. The parameter estimates obtained agree substantially with those previously obtained using a more detailed knowledge of the species' biology.
Scup 293 Executive Summary The current biomass reference point for scup relies on the index of Sp... more Scup 293 Executive Summary The current biomass reference point for scup relies on the index of Spawning Stock Biomass (SSB) from the NEFSC spring trawl survey. Previous reviews of the stock assessment have indicated that while this index may be the most reliable fishery independent index of scup SSB, it is subject to a relatively high degree of inter-annual variability that reduces its utility as an indicator of stock status. Managers, scientists, and other stakeholders indicated a desire for a more reliable way to monitor the status of scup and support the annual specification of fishery regulations. The December 2008 Northeast Data Poor Stocks Peer Review Panel accepted a revised stock assessment using a statistical catch at age model (ASAP) as the basis for biological reference points and status determination for scup. The new model of scup population dynamics and the recommended reference points represent a more stable approach for monitoring stock status and specifying annual fishery regulations, compared with the current single index-based model. The new model integrates a broad array of fishery and survey input data and should be less sensitive to inter-annual changes in any single data component than the current model. The Peer Review Panel recommended F 40% as the proxy for F MSY , and the corresponding SSB F40% as the proxy for SSB MSY. The F 40% proxy for F MSY = 0.177, the proxy estimate for SSB MSY = 92,044 mt, and the proxy estimate for MSY = 16,161 mt (13,134 mt of landings, 3,027 mt of discards). The stock biomass threshold of ½ SSB MSY = ½ SSB F40% = 46,022 mt = 101.461 million lbs. The 2007 SSB estimate of 119,343 mt is 30% above SSB MSY = 92,044 mt, indicating the stock was not overfished. The F 2007 estimate of 0.054 is 31% of F MSY = 0.177, indicating overfishing was not occurring. Total catch (landings plus discards) was 7,867 mt in 2007, about 49% of MSY. The revised status determination represents a significant change from the recent biomass status update conducted in July 2008, which indicated that the stock was overfished in 2007, although not experiencing overfishing. While the accepted long-term MSY estimate appears feasible given historical evidence from the fishery, managers may wish to take an adaptive approach to the specification of fishery quotas in the short-term. Total fishery landings over the last five years (2003-2007) have averaged …
Summary There is currently no generally agreed methodological approach to adjusting projections t... more Summary There is currently no generally agreed methodological approach to adjusting projections to account for retrospective patterns in the stock assessment. This paper presents three alternative approaches and compares the resulting time series of spawning stock biomass, landings, and fishing mortality rate based on a summer flounder-like stock assessment. The three adjustments for retrospective patterns all reduce landings in the quota setting year, but the magnitude of the reduction is quite variable and the implications for future years in the projections are quite different. Adjusting the fishing mortality rate in the quota setting year is not recommended in the context of rebuilding programs because the future catches are greater than the unadjusted projections. Adjusting all ages in the starting population creates the largest decrease in projected catch, but typically cannot be justified based on the patterns observed at age. Making adjustments to the starting population based on the age specific retrospective patterns produces the most consistent approach, although the overall impact is relatively minor. A number of technical questions remain regarding exactly how to compute the retrospective adjustments at age. Management strategy evaluation work is required in the future to determine if any adjustment method performs better than the others.
This series is a secondary scientific series designed to assure the long-term documentation and t... more This series is a secondary scientific series designed to assure the long-term documentation and to enable the timely transmission of research results by Center and/or non-Center researchers, where such results bear upon the research mission of the Center (see the outside back cover for the mission statement). These documents receive internal scientific review, and most receive copy editing. The National Marine Fisheries Service does not endorse any proprietary material, process, or product mentioned in these documents. All documents issued in this series since April 2001, and several documents issued prior to that date, have been copublished in both paper and electronic versions. To access the electronic version of a document in this series, go to http://www.nefsc.noaa.gov/nefsc/publications/. The electronic version is available in PDF format to permit printing of a paper copy directly from the Internet. If you do not have Internet access, or if a desired document is one of the pre-April Editorial Treatment: To distribute this report quickly, it has not undergone the normal technical and copy editing by the Northeast Fisheries Science Center's (NEFSC's) Editorial Office as have most other issues in the NOAA Technical Memorandum NMFS-NE series. Other than the four covers and first two preliminary pages, all writing and editing have been performed by the authors listed within. Information Quality Act Compliance: In accordance with section 515 of Public Law 106-554, the Northeast Fisheries Science Center completed both technical and policy reviews for this report. These predissemination reviews are on file at the NEFSC Editorial Office. This assessment of the scup (Stenotomus chrysops) stock along the Atlantic coast (Massachusetts to North Carolina) is an update through 2011 of commercial and recreational fishery (MRIP) catch data, research survey indices of abundance, and the analyses of those data. The stock was not overfished and overfishing was not occurring in 2011 relative to the biological reference points established in the 2008 Northeast Data Poor Stocks (DPS) assessment. The fishing mortality rate (F) was estimated to be 0.034 in 2011, below the fishing mortality threshold reference point = Fishing mortality producing Maximum Sustainable Yield (FMSY) = F40% = 0.177. Spawning Stock Biomass (SSB) was estimated to be 190,424 metric tons (mt) = 420 million lbs in 2011, above the biomass target reference point = SSBMSY = SSB40% = 92,044 mt = 203 million lbs. recruitment estimates are influenced mainly by the assessment model stock-recruitment relationship. Since 1984, recruitment estimates from …
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