Macroinvertebrates of Lake Wamala, 2012-2013

Study Extent

Data was collected between 2012 and 2013 is representative sites, covering near shore, offshore, and river mouths habitats.

Sampling

At each site, a sample of macroinvertebrates was collected using a Ponar grab (238 cm2 open-jaw area). Three vertical hauls of sediment at each site were taken. These were mixed to form one composite. Each composite sample was sieved through a 400µm nitex mesh to concentrate the sample. All the samples were placed in labeled sample bottles and preserved with 5% sugar formalin solution for taxonomic identification and enumeration in the laboratory.
In the laboratory, the formalin-fixed benthic macroinvertebrate samples were rinsed by tap water to remove preservatives before the sorting of the organisms. All the animals were separated, counted, and identified to the smallest taxonomic level under a dissecting microscope. Appropriate taxonomic keys were used (Mandahl-Barth, 1954; Pennak, 1953; Merritt & Cummins, 1997). Numerical abundance (individuals per square metre, Ind.m-2) was estimated for each taxon.

Quality Control

In the field, samples were immediately treated with formalin to keep the organisms intact. To avoid loss of organisms during sample processing, appropriate mesh sizes during sieving. Appropriate taxonomic keys were used.

Method steps

1. 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.

Macro-invertebrates taxa identified to class, family and genus.

1. Ablabesmyia
   rank: genus
2. Bulinus
   rank: genus
3. Caenis
   rank: genus
4. Ceratopogonidae
   rank: family
5. Chaoborus
   rank: genus
6. Chironomidae
   rank: family
7. Chironomus
   rank: genus
8. Clinotanypus
   rank: genus
9. Cloeon
   rank: genus
10. Oligochaeta
    rank: class
11. Povilla adusta
    rank: species
12. Procladius
    rank: genus
13. Tanypus
    rank: genus

The resource covers Lake Wamala. The lake is a UNEP designated environmental change hotspot (https://na.unep.net/atlas/webatlas.php?id=391).