Welch, E. B. University of Washington, ebwelch@u.washington.edu
Jacoby, J. B. Seattle University, jacoby@seattleu.edu
Anderson, E. L. University of Washington,
Biggs, B. F. National Inst. Water & Atmospheric Research,
Quinn, J. M. National Inst. Water & Atmospheric Research,

 
INVERTEBRATE REMOVAL OF FILAMENTOUS ALGAE IN STREAMS
 
Removal of periphyton by grazers was measured in six outside channel experiments and one inside circulating aquarium experiment using representative taxa of mayflies, caddis flies and snails. With two exceptions, filamentous green algal (FGA) biomass was reduced below controls by 40 to 96% with grazing (removal) rates ranging from 1.1 to 6.4 mg chl a/g animal-d. Removal increased with grazer biomass, which was more important than grazer size or taxa, although there was no obvious threshold of grazers that controlled periphyton. Maintenance of adequate habitat for grazers may be as important as nutrient reduction in controlling periphyton.
 
Day: Friday, Feb. 5
Time: 11:30 - 11:45am
Location: Eldorado Hotel
 
Code: SS46FR1130E