Strong Delayed Interactive Effects of Metal Exposure and Warming: Latitude-Dependent Synergisms Persist Across Metamorphosis.
As contaminants are often more toxic at higher temperatures, predicting their impact under global warming remains a key challenge for ecological risk assessment. Ignoring delayed effects, synergistic interactions between contaminants and warming, and differences in sensitivity across species' ranges could lead to an important underestimation of the risks. We addressed all three mechanisms by studying effects of larval exposure to zinc and warming before, during, and after metamorphosis in Ischnura elegans damselflies from high- and low-latitude populations. By integrating these mechanisms into a single study, we could identify two novel patterns. First, during exposure zinc did not affect survival, whereas it induced mild to moderate postexposure mortality in the larval stage and at metamorphosis, and very strongly reduced adult lifespan. This severe delayed effect across metamorphosis was especially remarkable in high-latitude animals, as they appeared almost insensitive to zinc during the larval stage. Second, the well-known synergism between metals and warming was manifested not only during the larval stage but also after metamorphosis, yet notably only in low-latitude damselflies. These results highlight that a more complete life-cycle approach that incorporates the possibility of delayed interactions between contaminants and warming in a geographical context is crucial for a more realistic risk assessment in a warming world.
Laboratory of Aquatic Ecology, Evolution and Conservation, KU Leuven/University of Leuven , Charles Deberiotstraat 32 bus 2439, 3000 Leuven, Belgium.
Sara
0000-0002-6097-5307
S
Debecker
Laboratory of Aquatic Ecology, Evolution and Conservation, KU Leuven/University of Leuven , Charles Deberiotstraat 32 bus 2439, 3000 Leuven, Belgium.|National Institute of Aquatic Resources, Technical University of Denmark , Jægersborg Alle 1D, Charlottenlund 2920, Denmark.|Department of Freshwater Aquaculture, Institute of Aquaculture, Nha Trang University , No 2 Nguyen Dinh Chieu, Nha Trang, 650000, Vietnam.
Khuong V
KV
Dinh
Laboratory of Aquatic Ecology, Evolution and Conservation, KU Leuven/University of Leuven , Charles Deberiotstraat 32 bus 2439, 3000 Leuven, Belgium.
Robby
R
Stoks
D000818:Animals; D057232:Global Warming; D007814:Larva / Q000187:drug effects; D008670:Metals / Q000494:pharmacology; D008675:Metamorphosis, Biological / Q000187:drug effects*; D063191:Odonata / Q000187:drug effects*
D008670:Metals