Hershey, A. E. University of North Carolina-Greensboro, anne_hershey@uncg.edu
Bothwell, M. L. National Water Research Institute Pacific Biological Station, bothwellm@pbs.dfo.ca
Ulseth, A. University of Minnesota-Duluth, aulseth@d.umn.edu
Lee, J. F. University of Minnesota-Duluth,

We measured UV effects on stream algae and insects in two arctic Alaskan streams. Because DOC is known to attenuate the effects of UV radiation on aquatic organisms we selected one stream with low DOC and a second stream with high DOC for comparison. Within each stream, UV was manipulated using plastic "screens". One type of screen was opaque to UVA and UVB radiation while the other was transparent to both UVA and UVB. Results to date show that there were no noticeable UV effects in Toolik Inlet, the high DOC stream. In low DOC Galbraith stream, UV radiation resulted in slightly lower algal biomass accumulation on stream tiles, but on tubes of the chironomid larva, Orthocladius rivulorum, chlorophyll a was slightly higher and larvae spent approximately 60% more time grazing under UV transparent screens, than under UV opaque screens. These preliminary results suggest that high DOC effectively protects arctic stream community components from UV effects, but under low DOC conditions, UV effects are closely tied to food web processes.
Day: Tuesday, Feb. 2
Time: 04:00 - 04:15pm
Location: Eldorado Hotel
Code: SS15TU0400E