The effects of low-level pharmaceuticals on stream biofilm structure and function across a land-use gradient in streams of the Huron River watershed

<p>Pharmaceuticals and personal care products (PPCPs) are a contaminant class of worldwide concern. Their environmental omnipresence indicates they may be a potential source of global change, and ecosystem-scale impacts at non-lethal levels have not been fully explored. We used stream biofilms to assess ecosystem responses to PPCPs. Biofilms were cultivated in streams draining areas of different land use and then exposed to triclosan, diphenhydramine, and sulfamethoxazole-trimethoprim treatments. We found evidence that low levels of these PPCPs affected some, but not all, aspects of biofilm processes and bacterial community composition. Bacterial carbon uptake was reduced (p = 0.06) and we found shifts in biofilm community composition following treatments. However, maximum photosynthetic efficiency, decomposition, and microbial physiological profiles showed no significant effect of PPCPs. Still, changes in bacterial activity and composition suggest that PPCPs may act as ecological disruptors at low levels, and further research is needed to assess ecosystem-scale effects.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Open Access Thesis

Discipline thesis:degree_discipline

Biology

Year dc:date.available

2020

Author dc:creator

• Stover, Elizabeth Mae

Contributors dc:contributor

• Kristin Judd, Ph.D.
• Steven Francoeur, Ph.D.
• Daniel Clemans, Ph.D.

• biofilms
• diphenhydramine
• ecology
• land use
• sulfamethoxazole-trimethoprim
• triclosan
• Biology
• Ecology and Evolutionary Biology
• Environmental Sciences

Repository record dc:identifier

https://commons.emich.edu/theses/1012

OAI identifier oai:identifier

oai:commons.emich.edu:theses-2401