The influence of simulated immigration and chemical persistence on recovery of macroinvertebrates from cypermethrin and 3,4-dichloroaniline exposure in aquatic microcosms.
Pest Manag Sci
; 65(6): 678-87, 2009 Jun.
Article
en En
| MEDLINE
| ID: mdl-19291705
ABSTRACT
BACKGROUND:
Chemical dissipation and organism immigration are considered important factors that influence recovery potential from perturbation of aquatic macroinvertebrates. Experiments were conducted to investigate the effect of simulated immigration on recovery of aquatic macroinvertebrates exposed in outdoor microcosms to ecotoxicologically similar concentrations of the rapidly dissipating pyrethroid insecticide cypermethrin (70 ng L(-1)) or the more persistent herbicide intermediate and degradate 3,4-dichloroaniline (10 mg L(-1)). Microcosms were covered with light-permeable mesh to prevent recolonisation. Immigration was simulated by the regular addition of organisms after treatment.RESULTS:
Microcosms exposed to 3,4-dichloroaniline treatment suffered substantial loss of taxon richness and by 10 months after treatment had only recovered where invertebrates had been added. Those treated with cypermethrin underwent an initial decline in certain crustacean and insect populations. These populations showed some signs of recovery over a period of 5 months through internal processes alone. However, rate of recovery was further enhanced where immigration was simulated, and in this case recovery had occurred around 100 days after treatment.CONCLUSION:
Although not the only factors involved, simulated immigration and chemical fate clearly influence the ability of communities to recover from chemical exposure. Consideration of immigration processes and development of models will help to increase the realism of risk assessments.
Texto completo:
1
Base de datos:
MEDLINE
Asunto principal:
Piretrinas
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Contaminantes Químicos del Agua
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Monitoreo del Ambiente
/
Ecosistema
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Invertebrados
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Compuestos de Anilina
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Pest Manag Sci
Asunto de la revista:
TOXICOLOGIA
Año:
2009
Tipo del documento:
Article