Spawner weight and ocean temperature drive Allee effect dynamics in Atlantic cod, <i>Gadus morhua</i>: inherent and emergent density regulation
<p>Stocks of Atlantic cod, <i>Gadus morhua</i>, show diverse recovery responses when fishing pressure is relieved. The expected outcome of reduced fishing pressure is that the population regains its size. However, there are also cod stocks that seem to be locked in a state of low a...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-09-01
|
| Series: | Biogeosciences |
| Online Access: | https://bg.copernicus.org/articles/20/3683/2023/bg-20-3683-2023.pdf |
| _version_ | 1797687454641160192 |
|---|---|
| author | A.-M. Winter N. Vasilyeva A. Vladimirov A. Vladimirov |
| author_facet | A.-M. Winter N. Vasilyeva A. Vladimirov A. Vladimirov |
| author_sort | A.-M. Winter |
| collection | DOAJ |
| description | <p>Stocks of Atlantic cod, <i>Gadus morhua</i>, show diverse recovery responses when fishing pressure is relieved. The expected outcome of reduced
fishing pressure is that the population regains its size. However, there are also cod stocks that seem to be locked in a state of low abundance from
which population growth does not occur (or only slowly occurs). A plausible explanation for this phenomenon can be provided by the Allee effect, which
takes place when recruitment per capita is positively related to population density or abundance. However, because of methodological limitations and
data constraints, such a phenomenon is often perceived as being rare or non-existent in marine fish.</p>
<p>In this study, we used time series of 17 Atlantic cod stocks to fit a family of population equations that consider the abundance of spawners, their
body weight and sea water temperature as independent components of recruitment. The developed stock-recruitment function disentangles the
effects of spawner abundance, spawner weight and temperature on recruitment dynamics and captures the diversity of density dependencies
(compensation, Allee effect) of the recruitment production in Atlantic cod.</p>
<p>The results show for 13 cod stocks an inherent spawner-abundance-related Allee effect. Allee effect strength, i.e., the relative change between
maximum and minimum recruitment per capita at low abundance, was increased when recruitment production was suppressed by unfavorable
changes in water temperature and/or in spawner weight. The latter can be a concomitant of heavy fishing or a result of temperature-related altered
body growth. Allee effect strength was decreased when spawner weight and/or temperature elevated recruitment production. We show how
anthropogenic stress can increase the risk of Allee effects in stocks where ocean temperature and/or spawner weight had been beneficial in the past
but are likely to unmask and strengthen an inherent Allee effect under future conditions.</p> |
| first_indexed | 2024-03-12T01:18:16Z |
| format | Article |
| id | doaj.art-1dad0891b5b74db295a1a3c1235075ae |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-03-12T01:18:16Z |
| publishDate | 2023-09-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-1dad0891b5b74db295a1a3c1235075ae2023-09-13T10:03:12ZengCopernicus PublicationsBiogeosciences1726-41701726-41892023-09-01203683371610.5194/bg-20-3683-2023Spawner weight and ocean temperature drive Allee effect dynamics in Atlantic cod, <i>Gadus morhua</i>: inherent and emergent density regulationA.-M. Winter0N. Vasilyeva1A. Vladimirov2A. Vladimirov3Wageningen Marine Research, Wageningen University and Research, Ijmuiden, the NetherlandsInterdisciplinary Laboratory for Mathematical Modeling of Soil Systems, V.V. Dokuchaev Soil Science Institute, Pyzhevsky per. 7/2, 119017 Moscow, Russian FederationInterdisciplinary Laboratory for Mathematical Modeling of Soil Systems, V.V. Dokuchaev Soil Science Institute, Pyzhevsky per. 7/2, 119017 Moscow, Russian FederationBogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Russian Federation<p>Stocks of Atlantic cod, <i>Gadus morhua</i>, show diverse recovery responses when fishing pressure is relieved. The expected outcome of reduced fishing pressure is that the population regains its size. However, there are also cod stocks that seem to be locked in a state of low abundance from which population growth does not occur (or only slowly occurs). A plausible explanation for this phenomenon can be provided by the Allee effect, which takes place when recruitment per capita is positively related to population density or abundance. However, because of methodological limitations and data constraints, such a phenomenon is often perceived as being rare or non-existent in marine fish.</p> <p>In this study, we used time series of 17 Atlantic cod stocks to fit a family of population equations that consider the abundance of spawners, their body weight and sea water temperature as independent components of recruitment. The developed stock-recruitment function disentangles the effects of spawner abundance, spawner weight and temperature on recruitment dynamics and captures the diversity of density dependencies (compensation, Allee effect) of the recruitment production in Atlantic cod.</p> <p>The results show for 13 cod stocks an inherent spawner-abundance-related Allee effect. Allee effect strength, i.e., the relative change between maximum and minimum recruitment per capita at low abundance, was increased when recruitment production was suppressed by unfavorable changes in water temperature and/or in spawner weight. The latter can be a concomitant of heavy fishing or a result of temperature-related altered body growth. Allee effect strength was decreased when spawner weight and/or temperature elevated recruitment production. We show how anthropogenic stress can increase the risk of Allee effects in stocks where ocean temperature and/or spawner weight had been beneficial in the past but are likely to unmask and strengthen an inherent Allee effect under future conditions.</p>https://bg.copernicus.org/articles/20/3683/2023/bg-20-3683-2023.pdf |
| spellingShingle | A.-M. Winter N. Vasilyeva A. Vladimirov A. Vladimirov Spawner weight and ocean temperature drive Allee effect dynamics in Atlantic cod, <i>Gadus morhua</i>: inherent and emergent density regulation Biogeosciences |
| title | Spawner weight and ocean temperature drive Allee effect dynamics in Atlantic cod, <i>Gadus morhua</i>: inherent and emergent density regulation |
| title_full | Spawner weight and ocean temperature drive Allee effect dynamics in Atlantic cod, <i>Gadus morhua</i>: inherent and emergent density regulation |
| title_fullStr | Spawner weight and ocean temperature drive Allee effect dynamics in Atlantic cod, <i>Gadus morhua</i>: inherent and emergent density regulation |
| title_full_unstemmed | Spawner weight and ocean temperature drive Allee effect dynamics in Atlantic cod, <i>Gadus morhua</i>: inherent and emergent density regulation |
| title_short | Spawner weight and ocean temperature drive Allee effect dynamics in Atlantic cod, <i>Gadus morhua</i>: inherent and emergent density regulation |
| title_sort | spawner weight and ocean temperature drive allee effect dynamics in atlantic cod i gadus morhua i inherent and emergent density regulation |
| url | https://bg.copernicus.org/articles/20/3683/2023/bg-20-3683-2023.pdf |
| work_keys_str_mv | AT amwinter spawnerweightandoceantemperaturedrivealleeeffectdynamicsinatlanticcodigadusmorhuaiinherentandemergentdensityregulation AT nvasilyeva spawnerweightandoceantemperaturedrivealleeeffectdynamicsinatlanticcodigadusmorhuaiinherentandemergentdensityregulation AT avladimirov spawnerweightandoceantemperaturedrivealleeeffectdynamicsinatlanticcodigadusmorhuaiinherentandemergentdensityregulation AT avladimirov spawnerweightandoceantemperaturedrivealleeeffectdynamicsinatlanticcodigadusmorhuaiinherentandemergentdensityregulation |