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Interaction between stress induced by competition, predation, and an insecticide on the response of aquatic invertebrates
Author(s) -
Van den Brink Paul J.,
Klein Sylvan L.,
Rico Andreu
Publication year - 2017
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.3788
Subject(s) - pulex , daphnia pulex , intraspecific competition , intraguild predation , biology , interspecific competition , gammarus pulex , predation , population , ecology , daphnia , predator , zoology , amphipoda , zooplankton , crustacean , demography , sociology
The present study investigated the effects of species interactions like competition and (intraguild) predation on the sensitivity of aquatic organisms to the insecticide chlorpyrifos. In the first experiment, combined effects of chlorpyrifos and different levels of intraspecific and interspecific interaction were assessed on Gammarus pulex survival using Asellus aquaticus as an interacting species. Intraspecific and interspecific interactions increased the time to extinction of G. pulex up to a factor of 2, most likely because of the cannibalistic nature of G. pulex and its intraguild predation on A. aquaticus under stress conditions. In the second experiment, combined effects of chlorpyrifos and intraspecific and interspecific interaction were assessed on Daphnia pulex abundance using Brachionus calyciflorus as a competing species and Chaoborus sp. larvae as a predator. Intraspecific and interspecific interactions significantly affected the D. pulex population structure, but they did not influence the total population size. Predation decimated D. pulex abundance; however, interacting effects of predation and chlorpyrifos exposure were less noticeable at high exposure concentrations because of the reduced predatory efficiency of Chaoborus sp. larvae. The present study shows that species interactions do not always increase the vulnerability of aquatic populations to chemical stress and that some interactions (e.g., cannibalism and intraguild predation) or reduced predator grazing pressure can alleviate competition and predation stress on population‐level insecticide effects under food‐limiting conditions. Environ Toxicol Chem 2017;36:2485–2492. © 2017 SETAC