Structural and functional effects of a short-term pyrethroid pulse exposure on invertebrates in outdoor stream mesocosms.
Sci Total Environ
; 610-611: 810-819, 2018 Jan 01.
Article
en En
| MEDLINE
| ID: mdl-28826119
ABSTRACT
Agricultural land-use frequently results in short pulse exposures of insecticides such as pyrethroids in river systems, adversely affecting local invertebrate communities. In order to assess insecticide-induced effects, stream mesocosms are used within higher tier aquatic risk assessment. Regulatory acceptable concentrations (RACs) derived from those studies are often higher compared with tier 1 RACs. Hence, the present mesocosm study evaluates this aspect using a pulse exposure scenario typical for streams and the pyrethroid insecticide etofenprox. A 6-h pulse exposure with measured concentrations of 0.04, 0.3 and 5.3µgL-1 etofenprox was used. We considered abundance, drift and emergence of invertebrates as structural endpoints and the in situ-measured feeding rates of the isopod Asellus aquaticus as functional endpoint. Most prominent effects were visible at 5.3µgL-1 etofenprox which caused adverse effects of up to 100% at the individual and population level, as well as community structure alterations. Transient effects were observed for invertebrate drift (effect duration ≤24h) and for the invertebrate community (9 days after exposure) at 0.3µgL-1 etofenprox. Furthermore, 0.04µgL-1 etofenprox affected the abundance of the mayfly Cloeon simile (decrease by 66%) and the feeding rate of A. aquaticus (decrease by 44%). Thus, implications for the functional endpoint leaf litter breakdown in heterotrophic ecosystems may be expected. A hypothetical RAC derived from the present mesocosm study (0.004µgL-1) is in line with the official tier 1 RAC (0.0044µgL-1) and thus shows that the present mesocosm study did not result in a higher RAC.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Contaminantes Químicos del Agua
/
Isópodos
/
Ríos
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Insecticidas
/
Insectos
Tipo de estudio:
Risk_factors_studies
Límite:
Animals
Idioma:
En
Revista:
Sci Total Environ
Año:
2018
Tipo del documento:
Article