Title

Effects of UV Radiation on Wetland Periphyton: Algae, Bacteria, and Extracellular Polysaccharides

Document Type

Article

Publication Date

6-1-2009

Department

Biological Sciences

Abstract

To study the effects of UV radiation on wetland periphyton, glass substrata were placed under acrylic mesocosms in a small freshwater marsh in Michigan, USA. One treatment excluded light in the UV range (<400nm), and another allowed the passage of all light. Substrata were sampled on four dates during August and September 2004. Chlorophyll a, algal community composition., ash-free dry mass, bacterial density and viability, and total extracellular polysaccharide (EPS) content were measured. Algal biomass, algal community composition, bacterial abundance, and ash-free dry mass were relatively insensitive to UV treatment; however, the proportion of non-viable bacteria (p = 0.006) and area-specific EPS content (p = 0.025) were significantly greater in the UV-exposed treatment. These results suggest that ambient levels of UV can damage periphytic bacteria and may cause corresponding functional changes within naturally occurring periphytic communities.

Publication Title

Journal of Freshwater Ecology

Volume

24

Issue

2

First Page

315

Last Page

326