Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1016/j.aquatox.2011.09.012
Titel (primär) Competition increases toxicant sensitivity and delays the recovery of two interacting populations
Autor Foit, K.; Kaske, O.; Liess, M.
Quelle Aquatic Toxicology
Erscheinungsjahr 2012
Department OEKOTOX
Band/Volume 106-107
Seite von 25
Seite bis 31
Sprache englisch
Keywords Indirect effect; Intraspecific competition; Interspecific competition; Community; Daphnia magna; Culex pipiens

We investigated how persistent competitive pressure alters toxicant sensitivity and recovery from a pesticide pulse at community level. Interacting populations of Daphnia (Daphnia magna) and Culex larvae (Culex pipiens molestus) were pulse-exposed (48 h) to the pyrethroid fenvalerate. The abundance and biomass of the populations were monitored by non-invasive image analysis. Shortly after exposure, Daphnia showed a concentration–response relationship with the toxicant with an LC50 of 0.9 μg/L. Culex larvae were slightly less sensitive with an LC50 of 1.7 μg/L. For both species, toxicant sensitivity increased with the population biomass of the respective species before exposure, which is explained by intraspecific competition. Several weeks after exposure to the highest treatment concentration of 1 μg/L, the slight differences in sensitivity between the two species were amplified to contrasting long-term effects due to interspecific competition: high interspecific competition impaired the recovery of Daphnia. Subsequently, Culex larvae profited from the slow recovery of Daphnia and showed an increased success of emergence. We conclude that, in natural systems where competition is present, such competitive processes might prolong the recovery of the community structure. Hence, natural communities might be disturbed for a longer period by toxic exposure than predicted from single-species tests alone.
dauerhafte UFZ-Verlinkung
Foit, K., Kaske, O., Liess, M. (2012):
Competition increases toxicant sensitivity and delays the recovery of two interacting populations
Aquat. Toxicol. 106-107 , 25 - 31 10.1016/j.aquatox.2011.09.012