Glen Canyon Dam and the Colorado River: Diseases in the Grand Canyon.

1. Glen Canyon Dam and the Colorado River:Diseases in the Grand Canyon. By Stephanie Boone

2. Effects of the Glen Canyon Dam on the Colorado River • Ecosystem changes • Water • Riparian vegetation • Sediment • Native and non-native fish. • Native American cultural and archeological sites.

3. Before Flow rates, sediment loads, and water temperatures varied from year to year and season to season. Heavy runoffs ( snow from Rocky Mountains)produce flows greater than 100,000 cfs during late spring and early summer. Flows in late summer , fall and winter less than 3,00 cfs. Water temperatures ranged from near freezing in winter to more than 80 F in late summer. After Daily variations instead of seasonal variations. Mean daily flows exceed 30,000 cfs about 3% of the time and less than 5,000 cfs about 10% of the time. Minimum and maximum daily releases range from 12,000 to 16,000 cfs. * Fluctuations mean the difference of 10 feet between low and high water on a given day. Effects on theWaterin the Colorado River

4. Effects on theRiparian Vegetationin the Colorado River • Before the dam riparian vegetation was scoured from the river banks during seasonal high water flows. • Vegetation permitted to develop at lower elevations in new zones. • More than 1,000 acres of additional habitat for native wildlife. • Marshes now occur that enhance plant diversity in the river corridor.

5. Effects on theSedimentin the Colorado River • Loss of sand from camping beaches. • Sand gets trapped behind dam. • Build-up of rapids at tributary mouths. • Drop in flow reduced ability to move debris. Build-up makes it more dangerous. • Silting up of fish habitats. • Decrease in yearly flooding has allowed silt to build-up in back cannels used as fish habitats.

6. Effects on theFishin the Colorado River • 3 native species *Colorado squawfish, bony chub and roundtail chub have disappeared. • 2 native species * humpback chub and razor back sucker, endangered. • 1 native species * flannelmouth sucker is a candidate for listing under the endangered species act. • 2 native species * bluehead sucker and speckle dace are relatively common.

7. Effects on theFishin the Colorado River • Majority of the non-native species – Coldwater trout. • Declines due to habitat changes, competition and predation. • A controlled flood was held in March and April 1996. * Researchers hope that the flood cleaned silt out of backwater channels used as habitats by native fish.

8. Diseases on thein the Colorado River • Since 1972 there have been ongoing outbreaks on the river. • Outbreaks in 1994 to 2000 involved more than 200 persons- river rafters. Symptoms consistent with norovirus infection. • 2 Outbreaks in 2002 and 2003 were found to be positive for norovirus.

9. Environmental Samples *Samples were obtained portable toilets of ill rafters and hikers. *Samples were also obtained from the Colorado River, Lees Ferry, Phantom Ranch, sewage treatment plant inside Glenn Canyon Dam. *Water sample collection by filtration with 1MDS filters. *Volumes collected - 100 gallons. *Samples transported on ice and frozen at -20 C. *Water samples were eluted from the filter using beef extract followed by organic flocculation and reconcentration Ben

10. Hepatitis A virus Estimated 1.4 cases worldwide. 37,000 per year in the US. Primers * capsid protein. 192 bp product. Enterovirus includes poliovirus, coxsackievirus, echovirus, enteroviruses 68-71. Viruses most often detected in polluted water. Primer * conserved region of nonstructural protein. 197 bp product Viruses Investigated

11. Results HAV Polio

12. Conclusions • Don’t go rafting in the grand canyon. • Need more research in area to determine causative agents of outbreaks. Could be parasitic in nature. • CDC recommends: • Don not drink untreated river water. • Isolate ill individual. Keep off of trip for 10 days. • Filter water and disinfect. • Wash hands frequently.