The effects of small fish presence on a species-poor community dominated by omnivores: Example of a size-based trophic cascade
dc.contributor.author
dc.date.accessioned
2015-10-15T11:31:11Z
dc.date.available
2015-10-15T11:31:11Z
dc.date.issued
2012-05-01
dc.identifier.issn
0022-0981
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dc.description.abstract
Omniory is important in determining species interactions and weakening possible trophic cascade effects. The present study is focused on determining if an indirect effect of fish presence (trophic cascade effect) can be observed regardless of a high abundance of omnivores. With this aim a field experiment was carried out in a Mediterranean salt marsh. The natural top predator of these systems is a small and endangered fish, the Iberian toothcarp (Aphanius iberus). We wanted to assess if the presence of this fish could trigger a trophic cascade in the aquatic community. Six mesocosms were installed in a salt marsh lagoon without A. iberus presence, for two months. Twenty adult females of A. iberus were added to three mesocosms (fish treatment), while the other three were used as control (without any A. iberus addition). Physical and chemical water characteristics, as well as aquatic invertebrate samples (from bacteria to amphipoda, the largest organisms detected beside fish) were collected at the begining and the end of the experiment. To assess the trophic position of organisms, stable isotope analyses were used (13C and 15N). Our results show that the presence of A. iberus produces a trophic cascade even though only two trophic levels were differentiated by the stable isotope analysis. Body size appears to be determinant, since trophic interactions observed within the food web were mainly body-size dependent. Moreover, an unexpected positive but weak effect of A. iberus on macrophyte biomass was observed, caused probably by the decrease of small phytoplankton abundance. This effect may suppose an advantage for A. iberus, since macrophytes provide refuge and a food supply for this small fish
dc.description.sponsorship
This work was supported by a grant from the Spanish Ministerio de Ciencia e Innovacion, Programa de Investigacion Fundamental No Orientada (CGL2011-23907) and by a predoctoral grant from the University of Girona (ref. BR06/03). We would like to thank the Parc Natural dels Aiguamolls de l'Emporda for allowing us to perform the experiment at their facilities. We would also like to thank C. Conchillo, R. Lopez-Flores, A. Ruhi, A. Badosa and J. Sala for their field assistance during the experiment
dc.format.mimetype
application/pdf
dc.language.iso
eng
dc.publisher
Elsevier
dc.relation
info:eu-repo/grantAgreement/MICINN//CGL2011-23907/ES/EVALUACION DE LA CONEXION ENTRE LA ESTRUCTURA DE LAS REDES TROFICAS, EL ESPECTRO DE TAMAÑOS CORPORALES Y SUS DETERMINANTES AMBIENTALES EN LAGUNAS MEDITERRANEAS/
dc.relation.isformatof
Reproducció digital del document publicat a: http://dx.doi.org/10.1016/j.jembe.2012.03.004
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© Journal of Experimental Marine Biology and Ecology, 2012, vol. 418-419, p. 1-11
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Articles publicats (D-CCAA)
dc.rights
Tots els drets reservats
dc.title
The effects of small fish presence on a species-poor community dominated by omnivores: Example of a size-based trophic cascade
dc.type
info:eu-repo/semantics/article
dc.rights.accessRights
info:eu-repo/semantics/embargoedAccess
dc.embargo.terms
Cap
dc.date.embargoEndDate
info:eu-repo/date/embargoEnd/2026-01-01
dc.type.version
info:eu-repo/semantics/publishedVersion
dc.identifier.doi
dc.identifier.idgrec
018192
dc.contributor.funder
dc.relation.ProjectAcronym