Attainability of Accurate Age Frequencies for Ocean Quahogs (Arctica islandica) Using Large Datasets: Protocol, Reader Precision, and Error Assessment
Ocean quahogs (Arctica islandica) are the longest lived bivalve on Earth. Individuals on the deep continental shelf off Georges Bank can survive for centuries, and in the colder, boreal waters of Iceland, ages over 500 y can be reached. Ocean quahog landings in the United States represent a $24 mill...
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ftwilliammarycol:oai:scholarworks.wm.edu:vimsarticles-3221 2023-06-11T04:10:03+02:00 Attainability of Accurate Age Frequencies for Ocean Quahogs (Arctica islandica) Using Large Datasets: Protocol, Reader Precision, and Error Assessment Hemeon, Kathleen M. Powell, Eric N. Robillard, Eric Pace, Sara M. Redmond, Theresa E. Mann, Roger 2021-01-01T08:00:00Z application/pdf https://scholarworks.wm.edu/vimsarticles/2220 https://doi.org/10.2983/035.040.0206 https://scholarworks.wm.edu/context/vimsarticles/article/3221/viewcontent/Attainability_JSR.pdf unknown W&M ScholarWorks https://scholarworks.wm.edu/vimsarticles/2220 doi: doi:10.2983/035.040.0206 https://scholarworks.wm.edu/context/vimsarticles/article/3221/viewcontent/Attainability_JSR.pdf VIMS Articles Fisheries Science Peer-Reviewed Articles Aquaculture and Fisheries text 2021 ftwilliammarycol https://doi.org/10.2983/035.040.0206</p>10.2983/035.040.0206 2023-05-04T17:48:55Z Ocean quahogs (Arctica islandica) are the longest lived bivalve on Earth. Individuals on the deep continental shelf off Georges Bank can survive for centuries, and in the colder, boreal waters of Iceland, ages over 500 y can be reached. Ocean quahog landings in the United States represent a $24 million industry, yet assessment models operate with no age data because of the substantial sample size required to develop adequate population age distributions for such a long-lived species, the unknown error associated with age estimates, and the extensive time and financial investment required to create production-scale age datasets. Inclusion of age data for this species requires precision metrics to evaluate aging uncertainty such as percent agreement, percent error, coefficient of variation, and tests of bias. To move forward using error-validated age-composition data, a 3-fold error protocol was developed using a large dual-reader dataset (n = 610) from Georges Bank. First, a proxy age-validation study was performed to corroborate an aging method, followed by error evaluation in the context of age-reader bias, precision, and error frequency. Error thresholds were established for each of the three error methods. Georges Bank samples ranged from 33 to 261 y of age and met the predetermined error thresholds for bias (conditionally because of significant and nonsignificant results), precision (average coefficient of variation less than 7%), and error frequency (less than 10%). Consequently, age estimates were deemed acceptable to support age frequency analyses. Precision and bias error were greatest for the youngest animals and, in the context of age-reader bias, error rates were higher for young male ocean quahogs than for young females. Improved age validation of young, sex-differentiated A. islandica will constrain aging error and guide refinement of both aging and age-error protocols. Text Arctica islandica Iceland Ocean quahog W&M ScholarWorks |
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Open Polar |
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W&M ScholarWorks |
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unknown |
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Fisheries Science Peer-Reviewed Articles Aquaculture and Fisheries |
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Fisheries Science Peer-Reviewed Articles Aquaculture and Fisheries Hemeon, Kathleen M. Powell, Eric N. Robillard, Eric Pace, Sara M. Redmond, Theresa E. Mann, Roger Attainability of Accurate Age Frequencies for Ocean Quahogs (Arctica islandica) Using Large Datasets: Protocol, Reader Precision, and Error Assessment |
topic_facet |
Fisheries Science Peer-Reviewed Articles Aquaculture and Fisheries |
description |
Ocean quahogs (Arctica islandica) are the longest lived bivalve on Earth. Individuals on the deep continental shelf off Georges Bank can survive for centuries, and in the colder, boreal waters of Iceland, ages over 500 y can be reached. Ocean quahog landings in the United States represent a $24 million industry, yet assessment models operate with no age data because of the substantial sample size required to develop adequate population age distributions for such a long-lived species, the unknown error associated with age estimates, and the extensive time and financial investment required to create production-scale age datasets. Inclusion of age data for this species requires precision metrics to evaluate aging uncertainty such as percent agreement, percent error, coefficient of variation, and tests of bias. To move forward using error-validated age-composition data, a 3-fold error protocol was developed using a large dual-reader dataset (n = 610) from Georges Bank. First, a proxy age-validation study was performed to corroborate an aging method, followed by error evaluation in the context of age-reader bias, precision, and error frequency. Error thresholds were established for each of the three error methods. Georges Bank samples ranged from 33 to 261 y of age and met the predetermined error thresholds for bias (conditionally because of significant and nonsignificant results), precision (average coefficient of variation less than 7%), and error frequency (less than 10%). Consequently, age estimates were deemed acceptable to support age frequency analyses. Precision and bias error were greatest for the youngest animals and, in the context of age-reader bias, error rates were higher for young male ocean quahogs than for young females. Improved age validation of young, sex-differentiated A. islandica will constrain aging error and guide refinement of both aging and age-error protocols. |
format |
Text |
author |
Hemeon, Kathleen M. Powell, Eric N. Robillard, Eric Pace, Sara M. Redmond, Theresa E. Mann, Roger |
author_facet |
Hemeon, Kathleen M. Powell, Eric N. Robillard, Eric Pace, Sara M. Redmond, Theresa E. Mann, Roger |
author_sort |
Hemeon, Kathleen M. |
title |
Attainability of Accurate Age Frequencies for Ocean Quahogs (Arctica islandica) Using Large Datasets: Protocol, Reader Precision, and Error Assessment |
title_short |
Attainability of Accurate Age Frequencies for Ocean Quahogs (Arctica islandica) Using Large Datasets: Protocol, Reader Precision, and Error Assessment |
title_full |
Attainability of Accurate Age Frequencies for Ocean Quahogs (Arctica islandica) Using Large Datasets: Protocol, Reader Precision, and Error Assessment |
title_fullStr |
Attainability of Accurate Age Frequencies for Ocean Quahogs (Arctica islandica) Using Large Datasets: Protocol, Reader Precision, and Error Assessment |
title_full_unstemmed |
Attainability of Accurate Age Frequencies for Ocean Quahogs (Arctica islandica) Using Large Datasets: Protocol, Reader Precision, and Error Assessment |
title_sort |
attainability of accurate age frequencies for ocean quahogs (arctica islandica) using large datasets: protocol, reader precision, and error assessment |
publisher |
W&M ScholarWorks |
publishDate |
2021 |
url |
https://scholarworks.wm.edu/vimsarticles/2220 https://doi.org/10.2983/035.040.0206 https://scholarworks.wm.edu/context/vimsarticles/article/3221/viewcontent/Attainability_JSR.pdf |
genre |
Arctica islandica Iceland Ocean quahog |
genre_facet |
Arctica islandica Iceland Ocean quahog |
op_source |
VIMS Articles |
op_relation |
https://scholarworks.wm.edu/vimsarticles/2220 doi: doi:10.2983/035.040.0206 https://scholarworks.wm.edu/context/vimsarticles/article/3221/viewcontent/Attainability_JSR.pdf |
op_doi |
https://doi.org/10.2983/035.040.0206</p>10.2983/035.040.0206 |
_version_ |
1768384149735866368 |