Makayla Blake

Date of Graduation

Summer 2015

Degree

Master of Science in Biology

Department

Biology

Committee Chair

Daniel Beckman

Abstract

I investigated the effect of stream habitat and water quality on the growth coefficient and population structure of madtom catfishes (Noturus albater and Noturus exilis). Samples of madtoms were taken from 20 locations on Bull and Swan Creeks by kick-seining and electroshocking. Each site was sampled once from May through August of 2014. Physicochemical variables (total nitrogen, phosphorus, chloride, and pH) were measured, along with an assessment of the physical habitat (dissolved oxygen, temperature, substrate size, and site location). The fish were euthanized on site and the whole otolith was used to determine age. Growth coefficient did not differ between species. The age and population structure of madtoms collected were compared to the physical habitat, physiochemical variables and an Index of Biotic Integrity (IBI) of macroinvertebrates. Sites with lower IBI scores (indicating better water quality) had significantly (p<0.0005) higher growth coefficient and average ages. The average age of fish was also significantly greater in the presence of a low water bridge (p<0.0005). As the average depth of the water increased, the growth coefficient and average age both decreased significantly (p<0.0005). There was a significant negative correlation between increased stream width and average age of madtoms (p<0.0005). These results indicate that there is a correlation between better water quality and increases in growth rates and average ages. It also indicates that the habitat structure also has an effect on average ages in madtom catfishes with wider and deeper habitats correlating with lower average ages.

Keywords

madtoms, otoliths, aging, stream habitat, water quality

Subject Categories

Biology

Copyright

© Makayla Blake

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