Mouthpart deformities in Chironomidae (Diptera) as indicators of heavy metal pollution in northern Lake Victoria, Uganda

  • H Ochieng National Fisheries Resources Research Institute (NaFIRRI), PO Box 343, Jinja, Ugandala
  • ED de Ruyter van Steveninck UNESCO-IHE Institute for Water Education, PO Box 3015, Delft, NL-2601 DA, The Netherlands
  • FM Wanda National Fisheries Resources Research Institute (NaFIRRI), PO Box 343, Jinja, Uganda

Abstract

Due to the absence of appropriate and sensitive tools for monitoring heavy metal pollution in northern Lake Victoria (Uganda), this study investigated mouthpart deformities in chironomid larvae (Diptera) in relation to concentrations of lead, copper, cadmium and zinc in lake sediments, and to dissolved oxygen, pH and conductivity. The variables at two rural reference sites in Hannington Bay and two urban-industrial test sites in Napoleon Gulf and Fielding Bay near Jinja were compared. Of the total number of chironomids examined from the two urban-industrial sites, 4.7% and 3.7% (respectively) were deformed. No deformed chironomids were found at the two reference sites. Chironomid mouthpart deformities correlated with concentrations of copper and zinc among the listed metals, but with none of the physical variables. The presence of deformities in chironomid larvae was a sufficiently sensitive proxy measurement to indicate the presence of low concentrations of heavy metals. The higher incidences of mouthpart deformities observed in the larvae of Chironomus sp. II could make them potential bioindicator organisms for heavy metal pollution.

Keywords: early warning bioindications, pollutants, rural areas, stress response, urban-industrial

African Journal of Aquatic Science 2008, 33(2): 135–142
Published
2008-08-26
Section
Articles

Journal Identifiers


eISSN: 1727-9364
print ISSN: 1608-5914