Do differences in sensitivity between native and invasive amphipods explain their coexistence in Lake Constance? A case study with lambda-cyhalothrin.
Chemosphere
; 92(5): 483-9, 2013 Jul.
Article
en En
| MEDLINE
| ID: mdl-23541147
Invasive species are considered as one of the major threats for biodiversity worldwide. The Ponto-Caspian species Dikerogammarus villosus, for instance, spread throughout continental Europe and was recorded for the first time also within Lake Constance in 2003. Although D. villosus is a highly competitive species it was not capable of replacing the native Gammarus roeselii completely in this ecosystem, especially in the riparian zones of the highly agriculturally used island "Reichenau". As differences in pesticide sensitivity between both amphipod species may explain their distribution, the present study assessed the implication of the highly toxic pyrethroid lambda-cyhalothrin, which is authorized for application in the Lake Constance region, assuming the invasive species being more sensitive than the native one. However, both the feeding activity bioassays, which measured the leaf consumption over 7d (n=20), as well as the predation bioassay, which measured the predation rate upon Baetis nymphs in concert with the feeding activity on leaf material over 96 h (n=13), revealed an up to 5-fold higher tolerance of D. villosus towards lambda-cyhalothrin. These results suggest the investigated insecticide not being the trigger for the observed distribution pattern of both amphipod species. Hence, other factors like the diversity of habitat structures or the levels of ammonia may have facilitated the coexistence. Nevertheless, the present study uncovered a high leaf-shredding efficacy of the invasive species D. villosus suggesting that its role in the leaf decomposition process may have been underestimated in the past.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Piretrinas
/
Anfípodos
/
Insecticidas
/
Nitrilos
Tipo de estudio:
Diagnostic_studies
/
Prognostic_studies
Límite:
Animals
País/Región como asunto:
Europa
Idioma:
En
Revista:
Chemosphere
Año:
2013
Tipo del documento:
Article
País de afiliación:
Alemania
Pais de publicación:
Reino Unido