An experimental test of how parasites of predators can influence trophic cascades and ecosystem functioning.

Autor: Anaya-Rojas JM; Department of Biological Science, Florida State University, Tallahassee, Florida, 32306, USA.; Center for Evolution & Biogeochemistry, Eawag, Swiss Federal Institute for Aquatic Science and Technology, Aquatic Ecology Seestrasse 79, Kastanienbaum, 6047, Switzerland., Best RJ; Center for Evolution & Biogeochemistry, Eawag, Swiss Federal Institute for Aquatic Science and Technology, Aquatic Ecology Seestrasse 79, Kastanienbaum, 6047, Switzerland.; School of Earth and Sustainability, Northern Arizona University, 525 South Beaver Street, Flagstaff, Arizona, 86011, USA., Brunner FS; Institute of Integrative Biology, University of Liverpool, Liverpool, L69 3BX, UK.; School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK., Eizaguirre C; School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK., Leal MC; MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, Lisboa, 1749-016, Portugal.; Fish Ecology and Evolution Department, Center for Evolution & Biogeochemistry, Eawag, Swiss Federal Institute for Aquatic Science and Technology, Seestrasse 79, Kastanienbaum, 6047, Switzerland., Melián CJ; Fish Ecology and Evolution Department, Center for Evolution & Biogeochemistry, Eawag, Swiss Federal Institute for Aquatic Science and Technology, Seestrasse 79, Kastanienbaum, 6047, Switzerland., Seehausen O; Fish Ecology and Evolution Department, Center for Evolution & Biogeochemistry, Eawag, Swiss Federal Institute for Aquatic Science and Technology, Seestrasse 79, Kastanienbaum, 6047, Switzerland.; Institute of Ecology & Evolution, Aquatic Ecology & Evolution, University of Bern, Baltzerstrasse 6, Bern, 3012, Switzerland., Matthews B; Center for Evolution & Biogeochemistry, Eawag, Swiss Federal Institute for Aquatic Science and Technology, Aquatic Ecology Seestrasse 79, Kastanienbaum, 6047, Switzerland.
Jazyk: angličtina
Zdroj: Ecology [Ecology] 2019 Aug; Vol. 100 (8), pp. e02744. Date of Electronic Publication: 2019 May 28.
DOI: 10.1002/ecy.2744
Abstrakt: Parasites can shape the structure and function of ecosystems by influencing both the density and traits of their hosts. Such changes in ecosystems are particularly likely when the host is a predator that mediates the dynamics of trophic cascades. Here, we experimentally tested how parasite load of a small predatory fish, the threespine stickleback, can affect the occurrence and strength of trophic cascades and ecosystem functioning. In a factorial mesocosm experiment, we manipulated the density of stickleback (low vs. high), and the level of parasite load (natural vs. reduced). In addition, we used two stickleback populations from different lineages: an eastern European lineage with a more pelagic phenotype (Lake Constance) and a western European lineage with a more benthic phenotype (Lake Geneva). We found that stickleback caused trophic cascades in the pelagic but not the benthic food chain. Evidence for pelagic trophic cascades was stronger in treatments where parasite load of stickleback was reduced with an antihelmintic medication, and where fish originated from Lake Constance (i.e., the more pelagic lineage). A structural equation model revealed that differences in stickleback lineage and parasite load were most likely to impact trophic cascades via changes in the composition, rather than overall biomass, of zooplankton communities. Overall, our results provide experimental evidence that parasites of predators can influence the cascading effects of fish on lower trophic levels with consequences on ecosystem functioning.
(© 2019 by the Ecological Society of America.)
Databáze: MEDLINE
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