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
Effects on the Water in the Colorado River

• 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.

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Effects on the Riparian Vegetation in 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.

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Effects on the Sediment in 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 the Fish in 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.

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Effects on the Fish in 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.

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Diseases on the in 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.

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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
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Viruses Investigated

• 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

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Results
HAV
Polio
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Conclusions

• Dont 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.