Refining age at legal-size estimation in the Newfoundland & Labrador populations of the snow crab Chionoecetes opilio (Fabricius, 1788) (Decapoda: Brachyura: Oregoniidae)
Abstract Current knowledge of age at legal size in Newfoundland & Labrador (NL) and other snow-crab stocks is incomplete due to historic estimations not accounting for skip-molting growth delays. Previous work has shown skip-molting incidence to occasionally be very high in males, both in NL and...
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Oxford University Press (OUP)
2023
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Online Access: | http://dx.doi.org/10.1093/jcbiol/ruad067 https://academic.oup.com/jcb/article-pdf/43/4/ruad067/52837554/ruad067.pdf |
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croxfordunivpr:10.1093/jcbiol/ruad067 2023-12-31T10:05:54+01:00 Refining age at legal-size estimation in the Newfoundland & Labrador populations of the snow crab Chionoecetes opilio (Fabricius, 1788) (Decapoda: Brachyura: Oregoniidae) Mullowney, Darrell O’Connell, Nicole Kilada, Raouf Rochette, Rémy 2023 http://dx.doi.org/10.1093/jcbiol/ruad067 https://academic.oup.com/jcb/article-pdf/43/4/ruad067/52837554/ruad067.pdf en eng Oxford University Press (OUP) https://creativecommons.org/licenses/by/4.0/ Journal of Crustacean Biology volume 43, issue 4 ISSN 0278-0372 1937-240X Aquatic Science journal-article 2023 croxfordunivpr https://doi.org/10.1093/jcbiol/ruad067 2023-12-06T08:48:32Z Abstract Current knowledge of age at legal size in Newfoundland & Labrador (NL) and other snow-crab stocks is incomplete due to historic estimations not accounting for skip-molting growth delays. Previous work has shown skip-molting incidence to occasionally be very high in males, both in NL and some other major snow-crab stocks. This warrants research to better understand impacts of skip-molting on snow-crab age and growth dynamics, which are central to population assessment and resource management. We simulated the impact of skip-molting on growth dynamics of snow crabs from three regions around NL by coupling a nineteen year time series of molt-type probabilities derived from field trawl surveys to historical data on age-at-instar based on cohort analysis of wild populations that do not consider skip-molting in making age estimations. Trawl surveys and simulations showed that skip-molting is a prominent feature in NL snow crabs, with up to four skip-molts being a reasonable maximum possible estimate for males in portions of the NL snow-crab stock. A complementary analysis examining the ability to age snow crabs using gastric mill band counts showed overall strong agreement with published growth trajectories that were modified to include skip-molting as well as reasonable average age approximations for most crabs, but unexpectedly high variability in age estimates for individuals of a same instar stage and unexpectedly low age estimates for younger crabs. Our study leads to a refinement of age at legal size for NL snow crab from the current nine-year estimate to a range of 9–13 years. Although this range is deemed to capture virtually every crab reaching legal size in NL snow-crab populations, ages higher than 11 years to fishery recruitment (2 skip-molts) are relatively infrequent. Article in Journal/Newspaper Chionoecetes opilio Newfoundland Snow crab Oxford University Press (via Crossref) Journal of Crustacean Biology 43 4 |
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Oxford University Press (via Crossref) |
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croxfordunivpr |
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English |
topic |
Aquatic Science |
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Aquatic Science Mullowney, Darrell O’Connell, Nicole Kilada, Raouf Rochette, Rémy Refining age at legal-size estimation in the Newfoundland & Labrador populations of the snow crab Chionoecetes opilio (Fabricius, 1788) (Decapoda: Brachyura: Oregoniidae) |
topic_facet |
Aquatic Science |
description |
Abstract Current knowledge of age at legal size in Newfoundland & Labrador (NL) and other snow-crab stocks is incomplete due to historic estimations not accounting for skip-molting growth delays. Previous work has shown skip-molting incidence to occasionally be very high in males, both in NL and some other major snow-crab stocks. This warrants research to better understand impacts of skip-molting on snow-crab age and growth dynamics, which are central to population assessment and resource management. We simulated the impact of skip-molting on growth dynamics of snow crabs from three regions around NL by coupling a nineteen year time series of molt-type probabilities derived from field trawl surveys to historical data on age-at-instar based on cohort analysis of wild populations that do not consider skip-molting in making age estimations. Trawl surveys and simulations showed that skip-molting is a prominent feature in NL snow crabs, with up to four skip-molts being a reasonable maximum possible estimate for males in portions of the NL snow-crab stock. A complementary analysis examining the ability to age snow crabs using gastric mill band counts showed overall strong agreement with published growth trajectories that were modified to include skip-molting as well as reasonable average age approximations for most crabs, but unexpectedly high variability in age estimates for individuals of a same instar stage and unexpectedly low age estimates for younger crabs. Our study leads to a refinement of age at legal size for NL snow crab from the current nine-year estimate to a range of 9–13 years. Although this range is deemed to capture virtually every crab reaching legal size in NL snow-crab populations, ages higher than 11 years to fishery recruitment (2 skip-molts) are relatively infrequent. |
format |
Article in Journal/Newspaper |
author |
Mullowney, Darrell O’Connell, Nicole Kilada, Raouf Rochette, Rémy |
author_facet |
Mullowney, Darrell O’Connell, Nicole Kilada, Raouf Rochette, Rémy |
author_sort |
Mullowney, Darrell |
title |
Refining age at legal-size estimation in the Newfoundland & Labrador populations of the snow crab Chionoecetes opilio (Fabricius, 1788) (Decapoda: Brachyura: Oregoniidae) |
title_short |
Refining age at legal-size estimation in the Newfoundland & Labrador populations of the snow crab Chionoecetes opilio (Fabricius, 1788) (Decapoda: Brachyura: Oregoniidae) |
title_full |
Refining age at legal-size estimation in the Newfoundland & Labrador populations of the snow crab Chionoecetes opilio (Fabricius, 1788) (Decapoda: Brachyura: Oregoniidae) |
title_fullStr |
Refining age at legal-size estimation in the Newfoundland & Labrador populations of the snow crab Chionoecetes opilio (Fabricius, 1788) (Decapoda: Brachyura: Oregoniidae) |
title_full_unstemmed |
Refining age at legal-size estimation in the Newfoundland & Labrador populations of the snow crab Chionoecetes opilio (Fabricius, 1788) (Decapoda: Brachyura: Oregoniidae) |
title_sort |
refining age at legal-size estimation in the newfoundland & labrador populations of the snow crab chionoecetes opilio (fabricius, 1788) (decapoda: brachyura: oregoniidae) |
publisher |
Oxford University Press (OUP) |
publishDate |
2023 |
url |
http://dx.doi.org/10.1093/jcbiol/ruad067 https://academic.oup.com/jcb/article-pdf/43/4/ruad067/52837554/ruad067.pdf |
genre |
Chionoecetes opilio Newfoundland Snow crab |
genre_facet |
Chionoecetes opilio Newfoundland Snow crab |
op_source |
Journal of Crustacean Biology volume 43, issue 4 ISSN 0278-0372 1937-240X |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1093/jcbiol/ruad067 |
container_title |
Journal of Crustacean Biology |
container_volume |
43 |
container_issue |
4 |
_version_ |
1786837624593317888 |