Acute toxicity of pyraclostrobin and trifloxystrobin to Hyalella azteca

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.

Section: Survivalmentioning

confidence: 99%

Effects of two commonly used fungicides on the amphipod Austrochiltonia subtenuis

Keough

Long

et al. 2016

“…These findings, and the work of others, indicate that the increased use of fungicides in the United States [14,15], and the expected increase in use globally [55], are likely to pose significant risks to leaf-derived nutrient cycling in streams. These findings, and the work of others, indicate that the increased use of fungicides in the United States [14,15], and the expected increase in use globally [55], are likely to pose significant risks to leaf-derived nutrient cycling in streams.…”

Section: Fungicide Effects On Macroinvertebrates: Tusmentioning

confidence: 90%

“…Although boscalid is considered moderately to highly toxic to aquatic invertebrates [50], the high concentration in the present study (24 mg/L) falls well below the 48-h LC50 (5300 mg/L) and the 21-d chronic NOEC (1300 mg/L) of boscalid for D. magna (Table 1). Indeed, based on the 96-h LC10 of 12 mg/L pyraclostrobin for H. azteca [14], we might expect to see reduced survival of H. azteca exposed to 8.4 mg/L pyraclostrobin for 14 d in the PRISTINE treatment. Indeed, based on the 96-h LC10 of 12 mg/L pyraclostrobin for H. azteca [14], we might expect to see reduced survival of H. azteca exposed to 8.4 mg/L pyraclostrobin for 14 d in the PRISTINE treatment.…”

Section: Fungicide Effects On H Azteca Survival and Growthmentioning

confidence: 99%

“…Moreover, fungicide concentrations in the 0.5 mg/L to 1 mg/L range have been shown to contribute significantly to the predicted toxicity of such pesticide mixtures [2,10]. With the global use of fungicides expected to increase with climate change and increased use in the United States already evident [14,15], it is imperative that we understand and document the impacts fungicide mixtures have on stream ecosystem functions. With the global use of fungicides expected to increase with climate change and increased use in the United States already evident [14,15], it is imperative that we understand and document the impacts fungicide mixtures have on stream ecosystem functions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of two fungicide formulations on microbial and macroinvertebrate leaf decomposition under laboratory conditions

Elskus

Smalling

Hladik

et al. 2016

Aquatic fungi contribute significantly to the decomposition of leaves in streams, a key ecosystem service. Little is known, however, about the effects of fungicides on aquatic fungi and macroinvertebrates involved with leaf decomposition. Red maple (Acer rubrum) leaves were conditioned in a stream to acquire microbes (bacteria and fungi) or leached in tap water (unconditioned) to simulate potential reduction of microbial biomass by fungicides. Conditioned leaves were exposed to fungicide formulations QUILT (azoxystrobin + propiconazole) or PRISTINE (boscalid + pyraclostrobin) in the presence and absence of the leaf shredder, Hyalella azteca (amphipods; 7-d old at start of exposures) for 14 d at 23 °C. The QUILT formulations (∼0.3 μg/L, 1.8 μg/L, and 8 μg/L) tended to increase leaf decomposition by amphipods (not significant) without a concomitant increase in amphipod biomass, indicating potential increased consumption of leaves with reduced nutritional value. The PRISTINE formulation (∼33 μg/L) significantly reduced amphipod growth and biomass (p < 0.05), effects similar to those observed with unconditioned controls. The significant suppressive effects of PRISTINE on amphipod growth and the trend toward increased leaf decomposition with increasing QUILT concentration indicate the potential for altered leaf decay in streams exposed to fungicides. Further work is needed to evaluate fungicide effects on leaf decomposition under conditions relevant to stream ecosystems, including temperature shifts and pulsed exposures to pesticide mixtures. Environ Toxicol Chem 2016;35:2834-2844. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America.

“…Thus calculated LC50s were based solely on time‐weighted average (Equation ) pyraclostrobin concentrations. Time‐weighted average water concentrations ( C TWA ) were achieved by fitting a first‐order exponential decay function through average water concentrations measured over time and taking the average of the curve, so that

C_{TWA} = \frac{\int_{a}^{b} f false(x false) d x}{(b - a)}

where a = 0 h, b = 96 h, and f ( x ) = first‐order exponential decay function . Differences in H. trivolvis mortalities and bioconcentration factors (BCFs) were determined with IBM SPSS Statistics Data Editor.…”

Section: Methodsmentioning

confidence: 99%

Development of Helisoma trivolvis pond snails as biological samplers for biomonitoring of current‐use pesticides

Morrison¹,

Belden²

2016

Self Cite

Nontarget aquatic organisms residing in wetlands are commonly exposed to current-use pesticides through spray drift and runoff. However, it is frequently challenging to measure exposure because of rapid dissipation of pesticides from water and reduced bioavailability. The authors' hypothesis is that freshwater snails can serve as bioindicators of pesticide exposure based on their capacity to passively accumulate tissue residues. Helisoma trivolvis snails were evaluated as biomonitors of pesticide exposure using a fungicide formulation that contains pyraclostrobin and metconazole and is frequently applied to crops surrounding depressional wetlands. Exposure-response studies indicate that H. trivolvis are tolerant of pyraclostrobin and metconazole at concentrations >10 times those lethal to many aquatic species, with a median lethal concentration based on pyraclostrobin of 441 μg/L (95% confidence interval of 359-555 μg/L). Bioconcentration factors ranged from 137 mL/g to 211 mL/g and from 39 mL/g to 59 mL/g for pyraclostrobin and metconazole, respectively. Elimination studies suggested one-compartmental elimination and snail tissue half-lives (t50 ) of approximately 15 h and 5 h for pyraclostrobin and metconazole, respectively. Modeling derived toxicokinetic parameters in the context of an environmentally relevant pulsed exposure suggests that residues can be measured in snails long after water concentrations fall below detection limits. With high fungicide tolerance, rapid accumulation, and slow elimination, H. trivolvis may be viable for biomonitoring of pyraclostrobin and should be investigated for other pesticides. Environ Toxicol Chem 2016;35:2320-2329. © 2016 SETAC.