• DOI:10.1007/s10750-012-1201-2
• Corpus ID: 254554649

Epilithic diatoms as indicators in tropical African rivers (Lake Victoria catchment)

@article{Triest2012EpilithicDA,
  title={Epilithic diatoms as indicators in tropical African rivers (Lake Victoria catchment)},
  author={Ludwig Triest and H.B.O. Lung'ayia and George G Ndiritu and Abebe Beyene},
  journal={Hydrobiologia},
  year={2012},
  volume={695},
  pages={343 - 360},
  url={https://api.semanticscholar.org/CorpusID:254554649}
}

• L. Triest, H.B.O. Lung'ayia, +1 author A. Beyene
• Published in Hydrobiologia 22 June 2012
• Environmental Science

We investigated epilithic diatoms in rivers draining to the Nyanza Bay in Lake Victoria (Kenya) with the aim of determining environmental gradients in the assemblages and testing the usefulness of diatom metrics from temperate regions. Spatial and temporal variations of assemblages were studied in 12 sites of three rivers. Kibos, Nyando, and Kisat rivers contained 224 diatom taxa collected on seven sampling occasions over 4 years. Species richness showed a marginal decrease downstream and was… 

We investigated epilithic diatoms in rivers draining to the Nyanza Bay in Lake Victoria (Kenya) with the aim of determining environmental gradients in the assemblages and testing the usefulness of diatom metrics from temperate regions. Spatial and temporal variations of assemblages were studied in 12 sites of three rivers. Kibos, Nyando, and Kisat rivers contained 224 diatom taxa collected on seven sampling occasions over 4 years. Species richness showed a marginal decrease downstream and was the lowest at sites with high conductivity and ammonia–nitrogen levels. Two-Way Indicator Species Analysis and Canonical Correspondence Analysis revealed two major groups of river sites. Conductivity, alkalinity, turbidity, dissolved oxygen, and silicate were the most important variables influencing species distribution. Ecological diatom metrics of temperate regions and the Specific Pollution sensitivity Index showed good relationships with environmental variables. Both diatom assemblages and averaged indicator values were strong in predicting sites of ecological deterioration and in differentiating an upstream site of better quality (drinking water supply of Kisumu), thereby confirming epilithic diatoms as suitable water quality indicators in equatorial rivers. The use of metrics initially designed for temperate rivers, however, appears less valuable in good quality tropical rivers because potential indicators are not considered.