Taxa occurrences and composition of benthic macroinvertebrates in Lake Edward system, Uganda

Study Extent

The datasets present data for surveys conducted between 2011 and 2021.

Sampling

A ponar grab with an open jaw area of 238 cm2 was used to take samples of benthic macroinvertebrates. One to three hauls were taken from each sampling point. When more than one haul was taken, they were mixed to form a composite sample. The bottom type at each point was described from the grabbed contents. This was captured as location remarks. Samples were concentrated and then placed in labeled sample bottles and preserved with 5% formalin solution. In the laboratory, each sample was rinsed with water and then placed on a white flat-bottomed tray. Macro-invertebrates were sorted, and individual taxa identified to the lowest possible taxonomic level using identification keys (Mandahl-Barth, 1954), Pennak, 1953), Merritt and Cummins, 1997, De Moor et al. 2003). All taxa were recorded, and individuals of each taxon enumerated to estimate their densities.

Quality Control

The samples were immediately processed in the field and treated with formalin to keep the organisms of interest intact. To avoid loss of organisms during sample processing, nets with appropriate mesh sizes were used.

Method steps

1. Collection of the macro-invertebrates In the field, sediment samples were collected using a ponar grab with an open jaw surface area of 238 cm2. At each site, three sediment samples were obtained. The three samples were mixed and concentrated to form one composite sample for each site.
2. Preserving the samples The composite sample for each site was separately preserved in 5% formalin to maintain the organisms in good condition prior to analysis in the laboratory.
3. Identification of macro-invertebrates In the laboratory, formalin was rinsed off from each sample and placed in white flat-bottomed trays. Using pairs of forceps, all benthic macro invertebrates were sorted from the sediment and the individual taxa identified to the lowest possible taxonomic level using appropriate identification keys and a dissecting binocular microscope at 4x 25 magnification.

Aquatic macro invertebrates identified to order, family, genus or species

1. Ablabesmyia
   rank: genus
2. Baetidae
   rank: family
3. Caelatura
   rank: genus
4. Chaoborus
   rank: genus
5. Chironomidae
   rank: family
6. Chironomus
   rank: genus
7. Clinotanypus
   rank: genus
8. Corbicula africana
   rank: species
9. Ecnomus
   rank: genus
10. Libellulidae
    rank: genus
11. Melanoides tuberculata
    rank: species
12. Mutela
    rank: genus
13. Phyllomacromia
    rank: genus
14. Plesiopora
    rank: order
15. Procladius
    rank: genus
16. Progomphus
    rank: genus
17. Rhynchobdellida
    rank: order
18. Tanypus
    rank: genus
19. Tarnytarsus
    rank: genus
20. Tubifex
    rank: genus

Lake Edward system, and lakes Kayumbu and Chahafi.