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

the Grand Canyon.the Grand Canyon.By Stephanie BooneBy Stephanie Boone

Effects of the Glen Canyon Dam on Effects of the Glen Canyon Dam on the Colorado Riverthe Colorado River

• Ecosystem changesEcosystem changes– WaterWater– Riparian vegetation Riparian vegetation – SedimentSediment– Native and non-native Native and non-native

fish.fish.– Native American Native American

cultural and cultural and archeological sites. archeological sites.

Effects on theEffects on the WaterWater in the in the Colorado RiverColorado River

• BeforeBefore– Flow rates, sediment loads, Flow rates, sediment loads,

and water temperatures varied and water temperatures varied from year to year and season from year to year and season to season.to season.

– Heavy runoffs ( snow from Heavy runoffs ( snow from Rocky Mountains)Rocky Mountains) produce produce flows greater than 100,000 cfs flows greater than 100,000 cfs during late spring and early during late spring and early summer.summer.

– Flows in late summer , fall and Flows in late summer , fall and winter less than 3,00 cfs.winter less than 3,00 cfs.

– Water temperatures ranged Water temperatures ranged from near freezing in winter to from near freezing in winter to more than 80 F in late more than 80 F in late summer. summer.

• AfterAfter– Daily variations instead of Daily variations instead of

seasonal variations.seasonal variations.– Mean daily flows exceed Mean daily flows exceed

30,000 cfs about 3% of the 30,000 cfs about 3% of the time and less than 5,000 cfs time and less than 5,000 cfs about 10% of the time.about 10% of the time.

– Minimum and maximum daily Minimum and maximum daily releases range from 12,000 to releases range from 12,000 to 16,000 cfs. * Fluctuations 16,000 cfs. * Fluctuations mean the difference of 10 feet mean the difference of 10 feet between low and high water between low and high water on a given day.on a given day.

Effects on theEffects on the Riparian VegetationRiparian Vegetation in the Colorado Riverin the Colorado River

• Before the dam riparian Before the dam riparian vegetation was scoured from vegetation was scoured from the river banks during the river banks during seasonal high water flows.seasonal high water flows.

• Vegetation permitted to Vegetation permitted to develop at lower elevations in develop at lower elevations in new zones.new zones.

• More than 1,000 acres of More than 1,000 acres of additional habitat for native additional habitat for native wildlife.wildlife.

• Marshes now occur that Marshes now occur that enhance plant diversity in the enhance plant diversity in the river corridor.river corridor.

Effects on theEffects on the SedimentSediment in the in the Colorado RiverColorado River

• Loss of sand from Loss of sand from camping beachescamping beaches..– Sand gets trapped behind Sand gets trapped behind

dam.dam.

• Build-up of rapids at Build-up of rapids at tributary mouthstributary mouths..– Drop in flow reduced ability Drop in flow reduced ability

to move debris. Build-up to move debris. Build-up makes it more dangerous.makes it more dangerous.

• Silting up of fish habitats.Silting up of fish habitats.– Decrease in yearly flooding Decrease in yearly flooding

has allowed silt to build-up has allowed silt to build-up in back cannels used as in back cannels used as fish habitatsfish habitats.

Effects on theEffects on the FishFish in the Colorado in the Colorado RiverRiver

• 3 native species3 native species * Colorado squawfish, bony chub and roundtail chub have disappeared.

• 2 native species2 native species * humpback chub and razor back sucker, endangered.

• 1 native species1 native species * flannelmouth sucker is a candidate for listing under the endangered species act.

• 2 native species2 native species * bluehead sucker and speckle dace are relatively common.

• •

Effects on theEffects on the FishFish in the Colorado in the Colorado RiverRiver

• Majority of the non-native Majority of the non-native speciesspecies – – Coldwater trout.Coldwater trout.

• Declines due to habitat Declines due to habitat changes, competition and changes, competition and predation.predation.

• A controlled flood was A controlled flood was held in March and April held in March and April 1996. * Researchers 1996. * Researchers hope that the flood hope that the flood cleaned silt out of cleaned silt out of backwater channels used backwater channels used as habitats by native fish.as habitats by native fish.

DiseasesDiseases on the on the in the Colorado in the Colorado RiverRiver

• 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.

Environmental SamplesEnvironmental Samples

Ben

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

Viruses InvestigatedViruses Investigated

• Hepatitis A virusHepatitis A virus– Estimated 1.4 cases Estimated 1.4 cases

worldwide.worldwide.– 37,000 per year in the 37,000 per year in the

US. US. – Primers * capsid Primers * capsid

protein.protein.– 192 bp product192 bp product.

• EnterovirusEnterovirus– includes poliovirus, includes poliovirus,

coxsackievirus, coxsackievirus, echovirus, echovirus, enteroviruses 68-71.enteroviruses 68-71.

– Viruses most often Viruses most often detected in polluted detected in polluted water. water.

– Primer * conserved Primer * conserved region of nonstructural region of nonstructural protein.protein.

– 197 bp product197 bp product

ResultsResults

HAV Polio

ConclusionsConclusions

• 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.