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Mechanisms behind bottom-up effects: eutrophication increases fecundity by shortening the interspawning interval in stickleback

Anthropogenic eutrophication is altering aquatic environments by promoting primary production. This influences the population dynamics of consumers through bottom-up effects, but the underlying mechanisms and pathways are not always clear. To evaluate and mitigate effects of eutrophication on ecolog...

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Autores principales: Saarinen, Anne, Candolin, Ulrika
Formato: Online Artículo Texto
Lenguaje:English
Publicado: PeerJ Inc. 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7370929/
https://www.ncbi.nlm.nih.gov/pubmed/32742798
http://dx.doi.org/10.7717/peerj.9521
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author Saarinen, Anne
Candolin, Ulrika
author_facet Saarinen, Anne
Candolin, Ulrika
author_sort Saarinen, Anne
collection PubMed
description Anthropogenic eutrophication is altering aquatic environments by promoting primary production. This influences the population dynamics of consumers through bottom-up effects, but the underlying mechanisms and pathways are not always clear. To evaluate and mitigate effects of eutrophication on ecological communities, more research is needed on the underlying factors. Here we show that anthropogenic eutrophication increases population fecundity in the threespine stickleback (Gasterosteus aculeatus) by increasing the number of times females reproduce—lifetime fecundity—rather than instantaneous fecundity. When we exposed females to nutrient-enriched waters with enhanced algal growth, their interspawning interval shortened but the size of their egg clutches, or the size of their eggs, did not change. The shortening of the interspawning interval was probably caused by higher food intake, as algae growth promotes the growth of preferred prey populations. Enhanced female lifetime fecundity could increase offspring production and, hence, influence population dynamics. In support of this, earlier studies show that more offspring are emerging in habitats with denser algae growth. Thus, our results stress the importance of considering lifetime fecundity, in addition to instantaneous fecundity, when investigating the impact of human-induced eutrophication on population processes. At a broader level, our results highlight the importance of following individuals over longer time spans when evaluating the pathways and processes through which environmental changes influence individual fitness and population processes.
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spelling pubmed-73709292020-07-31 Mechanisms behind bottom-up effects: eutrophication increases fecundity by shortening the interspawning interval in stickleback Saarinen, Anne Candolin, Ulrika PeerJ Aquaculture, Fisheries and Fish Science Anthropogenic eutrophication is altering aquatic environments by promoting primary production. This influences the population dynamics of consumers through bottom-up effects, but the underlying mechanisms and pathways are not always clear. To evaluate and mitigate effects of eutrophication on ecological communities, more research is needed on the underlying factors. Here we show that anthropogenic eutrophication increases population fecundity in the threespine stickleback (Gasterosteus aculeatus) by increasing the number of times females reproduce—lifetime fecundity—rather than instantaneous fecundity. When we exposed females to nutrient-enriched waters with enhanced algal growth, their interspawning interval shortened but the size of their egg clutches, or the size of their eggs, did not change. The shortening of the interspawning interval was probably caused by higher food intake, as algae growth promotes the growth of preferred prey populations. Enhanced female lifetime fecundity could increase offspring production and, hence, influence population dynamics. In support of this, earlier studies show that more offspring are emerging in habitats with denser algae growth. Thus, our results stress the importance of considering lifetime fecundity, in addition to instantaneous fecundity, when investigating the impact of human-induced eutrophication on population processes. At a broader level, our results highlight the importance of following individuals over longer time spans when evaluating the pathways and processes through which environmental changes influence individual fitness and population processes. PeerJ Inc. 2020-07-17 /pmc/articles/PMC7370929/ /pubmed/32742798 http://dx.doi.org/10.7717/peerj.9521 Text en ©2020 Saarinen and Candolin https://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ) and either DOI or URL of the article must be cited.
spellingShingle Aquaculture, Fisheries and Fish Science
Saarinen, Anne
Candolin, Ulrika
Mechanisms behind bottom-up effects: eutrophication increases fecundity by shortening the interspawning interval in stickleback
title Mechanisms behind bottom-up effects: eutrophication increases fecundity by shortening the interspawning interval in stickleback
title_full Mechanisms behind bottom-up effects: eutrophication increases fecundity by shortening the interspawning interval in stickleback
title_fullStr Mechanisms behind bottom-up effects: eutrophication increases fecundity by shortening the interspawning interval in stickleback
title_full_unstemmed Mechanisms behind bottom-up effects: eutrophication increases fecundity by shortening the interspawning interval in stickleback
title_short Mechanisms behind bottom-up effects: eutrophication increases fecundity by shortening the interspawning interval in stickleback
title_sort mechanisms behind bottom-up effects: eutrophication increases fecundity by shortening the interspawning interval in stickleback
topic Aquaculture, Fisheries and Fish Science
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7370929/
https://www.ncbi.nlm.nih.gov/pubmed/32742798
http://dx.doi.org/10.7717/peerj.9521
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