Effects of suspended sediment and desiccation on the benthic tailwater community in the Colorado River, USA
Shaver ML, Shannon JP, Wilson KP, Benenati PL, Blinn DW. 1997. Effects of suspended sediment and desiccation on the benthic tailwater community in the Colorado River, USA. Hydrobiologia: The International Journal on Limnology and Marine Sciences. 357(1-3):63-72
"We demonstrated that differences in habitat requirements by C. glomerata and Oscillatoria have a profound bottom-up influence on the foodweb in the tailwaters below Glen Canyon Dam in the Colorado River through Grand Canyon National Park, USA. We examined the effects of suspended sediment and desiccation on the colonization sequence of Cladophora glomerata and Oscillatoria spp. and the consequent effects on macroinvertebrates in each algal community in a series of reciprocal transplants in the regulated Colorado River, AZ. Our experiments showed that C. glomerata grows best in continuously submerged, clear-water, stable habitats, whereas Oscillatoria forms dense mat-like matrices of trichomes and sand in varial zones and habitats with high suspended sediments typical of many southwestern USA streams. Varial zone conditions have a stronger influence on community structure than habitats with high suspended sediments. Recruitment by chironomid larvae was less dependent on C. glomerata and less affected by suspended sediment and periodic desiccation than Gammarus lacustris. We estimated the energy from macroinvertebrate biomass associated with tufts of C. glomerata to be an order of magnitude higher than that in Oscillatoria matrices. Therefore, loss of C. glomerata and replacement of habitat more suitable for Oscillatoria as a result of regulated flows indirectly reduces potential energy flow in the Colorado River foodweb." [Cambridge Scientific Abstracts]
- Type
- Journal Article
- Authors
- Shaver, Michael; Shannon, Joseph; Wilson, K; Benenati, Peggy; Blinn, Dean
- Units
- GLCA
- Keywords
- Algae, Aquatic Habitats, Aquatic Sciences, Benthos, Colorado River, Dam Effects, Desiccation, Flow (Streamflow), Glen Canyon Dam Glen Canyon National Recreation Area, Macroinvertebrates, Sediment, tailwater