Life history traits vary between geographically distinct populations in a protogynous hermaphrodite

Abstract Sequential hermaphroditic species, such as blue cod (Parapercis colias), are particularly vulnerable to selective harvesting as it can directly influence the sex ratio, timing of sex change, and consequentially recruitment success. We analyzed the population structure, at which males domina...

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Main Authors: Stina Kolodzey, Stephen R. Wing
Format: Article
Language:English
Published: Wiley 2022-09-01
Series:Ecosphere
Subjects:
Online Access:https://doi.org/10.1002/ecs2.4237
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author Stina Kolodzey
Stephen R. Wing
author_facet Stina Kolodzey
Stephen R. Wing
author_sort Stina Kolodzey
collection DOAJ
description Abstract Sequential hermaphroditic species, such as blue cod (Parapercis colias), are particularly vulnerable to selective harvesting as it can directly influence the sex ratio, timing of sex change, and consequentially recruitment success. We analyzed the population structure, at which males dominate the populations, and modeled fecundity of blue cod from the Marlborough Sounds in the north of New Zealand's South Island, and compared these results with previously collected data from a blue cod population in Fiordland on the southwest coast of the South Island. In addition to the geographical difference, there were differences in the time the two populations were sampled, and the fisheries management regime between regions. Within the Marlborough Sounds population, the length‐frequency distribution was skewed toward high numbers of smaller individuals with an average length of 290 ± 59 mm. In Fiordland, the average length of blue cod was 380 ± 78 mm. Larger proportions of males within each length class were observed in the Marlborough Sounds, whereas females were the dominant sex in the Fiordland population. The estimated length at which males dominate the population was significantly smaller for the Marlborough Sounds population (182 mm) than for blue cod from the Fiordland population (419 mm). Geographical and temporal differences in sampling likely played important roles in the observed life history differences, particularly in the observed differences in growth. However, when compared to length and age data from national surveys, the life history traits of both sampled populations have remained relatively stable over the past 15 years, indicating that differences in population management and fishing pressure are the most likely explanation for the observed differences in length frequency and length‐at‐sex‐change. For effective and sustainable management of species with sequential hermaphroditism, size‐sensitive management, particularly protecting larger individuals, is required to avoid declines in length structure and recruitment limitations.
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spelling doaj.art-e886863314fe40b48f768e20dbe7440d2022-12-22T04:27:16ZengWileyEcosphere2150-89252022-09-01139n/an/a10.1002/ecs2.4237Life history traits vary between geographically distinct populations in a protogynous hermaphroditeStina Kolodzey0Stephen R. Wing1Department of Marine Science University of Otago Dunedin New ZealandDepartment of Marine Science University of Otago Dunedin New ZealandAbstract Sequential hermaphroditic species, such as blue cod (Parapercis colias), are particularly vulnerable to selective harvesting as it can directly influence the sex ratio, timing of sex change, and consequentially recruitment success. We analyzed the population structure, at which males dominate the populations, and modeled fecundity of blue cod from the Marlborough Sounds in the north of New Zealand's South Island, and compared these results with previously collected data from a blue cod population in Fiordland on the southwest coast of the South Island. In addition to the geographical difference, there were differences in the time the two populations were sampled, and the fisheries management regime between regions. Within the Marlborough Sounds population, the length‐frequency distribution was skewed toward high numbers of smaller individuals with an average length of 290 ± 59 mm. In Fiordland, the average length of blue cod was 380 ± 78 mm. Larger proportions of males within each length class were observed in the Marlborough Sounds, whereas females were the dominant sex in the Fiordland population. The estimated length at which males dominate the population was significantly smaller for the Marlborough Sounds population (182 mm) than for blue cod from the Fiordland population (419 mm). Geographical and temporal differences in sampling likely played important roles in the observed life history differences, particularly in the observed differences in growth. However, when compared to length and age data from national surveys, the life history traits of both sampled populations have remained relatively stable over the past 15 years, indicating that differences in population management and fishing pressure are the most likely explanation for the observed differences in length frequency and length‐at‐sex‐change. For effective and sustainable management of species with sequential hermaphroditism, size‐sensitive management, particularly protecting larger individuals, is required to avoid declines in length structure and recruitment limitations.https://doi.org/10.1002/ecs2.4237blue codfecundityFiordlandlength frequencymarine reserveMarlborough Sounds
spellingShingle Stina Kolodzey
Stephen R. Wing
Life history traits vary between geographically distinct populations in a protogynous hermaphrodite
Ecosphere
blue cod
fecundity
Fiordland
length frequency
marine reserve
Marlborough Sounds
title Life history traits vary between geographically distinct populations in a protogynous hermaphrodite
title_full Life history traits vary between geographically distinct populations in a protogynous hermaphrodite
title_fullStr Life history traits vary between geographically distinct populations in a protogynous hermaphrodite
title_full_unstemmed Life history traits vary between geographically distinct populations in a protogynous hermaphrodite
title_short Life history traits vary between geographically distinct populations in a protogynous hermaphrodite
title_sort life history traits vary between geographically distinct populations in a protogynous hermaphrodite
topic blue cod
fecundity
Fiordland
length frequency
marine reserve
Marlborough Sounds
url https://doi.org/10.1002/ecs2.4237
work_keys_str_mv AT stinakolodzey lifehistorytraitsvarybetweengeographicallydistinctpopulationsinaprotogynoushermaphrodite
AT stephenrwing lifehistorytraitsvarybetweengeographicallydistinctpopulationsinaprotogynoushermaphrodite