Date of Award

Fall 5-14-2016

Level of Access

Campus-Only Thesis

Degree Name

Master of Science (MS)

Department

Wildlife Ecology and Wildlife Conservation

Advisor

Cynthia Loftin

Second Committee Member

Joseph Zydlewski

Third Committee Member

Erik Blomberg

Additional Committee Members

Robert Liliehom

Abstract

The Bumbuna Hydroelectric Dam was completed in 2009 and is located upstream of the Bumbuna Falls on the Seli River in Sierra Leone. Fish species diversity and composition in the river were assessed pre-impoundment (2006) from the estuary to the upper reaches of the river. Post-impoundment (2012) surveys focused on sites near the new dam. In 2006, we observed 81 species and 29 families over the longitudinal section of the river, with the greatest diversity observed in the open river reaches upstream of the estuary. There were clear discontinuities in species distributions and reduction in diversity upstream of Bumbuna Falls, a natural falls. Post-impoundment, we captured fewer species and families at the three sites nearest to the dam. Species richness and Shannon-Wiener and Jaccard’s diversity indices declined post-impoundment for the reservoir and

sites immediately downstream of the dam. Whereas Cyprinidae was the dominant family pre-impoundment, Cichlidae dominated the reservoir after impoundment (e.g., Tilapia joka and T. louka). Construction of the dam near Bambuma Falls may have mitigated overall effects of impoundment. While downstream species diversity remained unchanged, species composition shifted to cichlids. Effects of this and other dams are complex and are not fully characterized by diversity metrics.

The Bumbuna Hydroelectric Project Area is a mosaic of forest patches, savanna, riparian forest and agricultural lands with high prevalence of palm trees (Elaeis guinensis). Chimpanzee surveys and population estimates were conducted in 2006 using nest clusters and reconnaissance (recces) surveys to identify group size and follow chimpanzees. In 2013, we used nest observations with a traditional line transect method and distance sampling to estimate and compare the 2006 recce and estimates to the 2013 distance estimates. We calculated the density of chimpanzees to be 0.10 individuals/km2 (CV=63%; 95% CI=0.031-0.33), with a population of 6 individuals (CV=57%; 95% CI=2-17). The pre- (9; range 9-14) and post-impoundment (2; 2-17) BCA community estimates are similar for the different approaches. The majority of nest clusters were individual nests, and the largest nest cluster was 16. Most nests were in clusters of two and six nests. The majority of nests occurred on fruiting tree species. Chimpanzees consumed the pith and fruits of Elaies guineensis and Ficus spp. throughout the study period.

Share