| Autor: |
Crosa, G., Yaméogo, L., Calamari, D., Diop, M.E., Nabé, K., Kondé, F. |
| Jazyk: |
angličtina |
| Rok vydání: |
2019 |
| Předmět: |
|
| Popis: |
Within the Onchocerciasis Control Programme about 50,000 km of west African rivers have been regularly sprayed with larvicides to control the vector of dermal filariasis caused by Onchocerca volvulus. Since the beginning of the programme invertebrates and fish data were collected to monitor adverse effects on non-target organisms. The regular series of biological and hydrological data collected in two Guinean rivers were analysed to evaluate the effects of rotational larviciding with particular attention to permethrin, as preliminary acute toxicology tests and semi-field experiments suggest it has stronger effects on non-target fauna in respect to other larvicides. Invertebrates ard fish variations in biomass and species richness are seasonal and flow-related and the results presented here do not support any evidence of specific effects of permethrin application on the biological targets monitored. Larvicide applications influence community structures, putting pressure on some taxonomic groups, causing. for example, the rarefacion of some taxa. In spite of the above results, the scarcity of some invertebrate systematic units does not resuit in a significant reduction of total invertebrate density because of the corresponding increase in other systematic units. In nature the studied aquatic communities would rarely be in equilibrium because of frequent natural stresses, such as drougst and spate events, the biologicai variations discussed are to be considered ecologically acceptable. © 2001 Elsevier Science Ltd. All rights reserved. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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