Effects of two commonly used fungicides on the amphipod Austrochiltonia subtenuis

Abstract

Fungicides are used widely in agriculture and have been detected in adjacent rivers and wetlands. However, relatively little is known about the potential effects of fungicides on aquatic organisms. The present study investigated the effects of 2 commonly used fungicides, the boscalid fungicide Filan and the myclobutanil fungicide Systhane 400 WP, on life history traits (survival, growth, and reproduction) and energy reserves (lipid, protein, and glycogen content) of the amphipod Austrochiltonia subtenuis under laboratory conditions, at concentrations detected in aquatic environments. Amphipods were exposed to 3 concentrations of Filan (1 μg active ingredient [a.i.]/L, 10 μg a.i./L, and 40 μg a.i./L) and Systhane (0.3 μg a.i./L, 3 μg a.i./L, and 30 μg a.i./L) over 56 d. Both fungicides had similar effects on the amphipod at the organism level. Reproduction was the most sensitive endpoint, with offspring produced in controls but none produced in any of the fungicide treatments, and total numbers of gravid females in all fungicide treatments were reduced by up to 95%. Female amphipods were more sensitive than males in terms of growth. Systhane had significant effects on survival at all concentrations, whereas significant effects of Filan on survival were observed only at 10 μg a.i./L and 40 μg a.i./L. The effects of fungicides on energy reserves of the female amphipod were different. Filan significantly reduced amphipod protein content, whereas Systhane significantly reduced the lipid content. The present study demonstrates wide-ranging effects of 2 common fungicides on an ecologically important species that has a key role in trophic transfer and nutrient recycling in aquatic environments. These results emphasize the importance of considering the long-term effects of fungicides in the risk assessment of aquatic ecosystems. Environ Toxicol Chem 2017;36:720-726. © 2016 SETAC.

Toxicological effects of fungicide mixtures on the amphipod Austrochiltonia subtenuis

“…Our results in terms of female growth and survival strongly support this hypothesis because Systhane had no effects on female head length (Table 1) and female survival (data not shown). These findings are also in agreement with our previous study showing that juvenile amphipods exposed to Systhane (0.3, 3, and 30 mg a.i./L) reached maturation later than control amphipods [28].…”

“…No significant differences in mortality were observed between treatments and the control after 7 or 28 d (Figure ). Our previous work showed that both Filan and Systhane significantly reduced the survival of A. subtenuis at 10 and 0.3 μg a.i./L after 7 d of exposure, respectively . In the present study, however, no significant effects were observed at even higher concentrations (40 μg a.i./L of Filan and 3 μg a.i./L of Systhane), both singly and in combination.…”

“…Furthermore, Filan had a significant effect on male head length at 1, 10, and 40 mg a.i./L (p ¼ 0.01, p ¼ 0.019, p ¼ 0.014, respectively), while a significant effect was observed only at the highest concentration of 40 mg a.i./L for females (p ¼ 0.008). Our previous studies have also shown that male and female amphipods respond differently to fungicide exposure in terms of growth [28]. The present study further indicated that juveniles were more sensitive to the tested fungicides in terms of growth than mature animals.…”

“…The present study and our 2 previous studies report on the wide range of effects that the fungicides Filan and Systhane have on 2 Australian amphipod species, Allorchestes compressa and A. subtenuis , at environmentally relevant concentrations under laboratory conditions. In summary, reproduction was the most sensitive endpoint for both single and mixture exposures.…”

Invertebrate biodiversity in apple orchards: agrichemical sprays as explanatory variables for inter‐orchard community differences

“…Furthermore, some fungicides can have direct effects on invertebrates. For example, myclobutanil has contact toxicity for the fungivorous coccinellid Psyllobora vigintimaculata (Sutherland et al ., ) and the aquatic amphipod Austrochiltonia subtenuis (Vu et al ., ) and mancozeb can affect the fertility of the predatory mite Phytoseiulus persimilis (Ditillo et al ., ), although it has relatively low toxicity to the predatory coccinellid Halmus chalybeus (Lo, ). Nitrogen fertilizers are known to affect herbivorous insects, particularly phloem sap‐sucking species, via changes in plant quality (Butler et al ., ) and the same may hold true for leaf‐feeding detritivores.…”