Mortality of waterbirds in the Upper Mississippi River

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Mortality of waterbirds in the Upper
Mississippi River
Jennifer Sauer USGSLa Crosse, Wisconsin Dr.
Rebecca Cole USGSMadison, Wisconsin Dr. Greg
Sandland, UW-La Crosse Dr. Roger Haro, UW-La
Crosse Jim Nissen USFWS La Crosse District Ed
Britton USFWS Savanna District
Upper Midwest Environmental Sciences Center
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Waterbird Mortalities
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Mortality Events
2007
1998
2006-8
1996-P
1992
2002-P
2001-4
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Bithynia tentaculata
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Cyathocotyle bushiensis (Coots) Sphaeridiotrema
globulus (Scaup, Coots) Leyogonimus polyoon
(Coots)
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Pathology

• Sphaeridiotrema
• reside in the small intestine
• feed on blood, causing severe blood loss and
  anemia
• Cyathocotyle
• reside in the ceca
• cause a disruption in water and electrolyte
  balance
• Leyogonimus polyoon
• infects primarily the upper and middle areas of
  the small intestine.
• severe enteritis characterized by thickening of
  the intestinal wall that blocks the lumen of the
  intestine

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Why are we concerned?
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Why are we concerned?
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Total Mortality Estimates
Pool 8
Pool 7
50 - 65
580 - 700
Fall 2002
6,100 - 7,600
Fall 2003
10-15
2,100 - 2,600
Fall 2004
150 - 200
5,300 - 7,000
Fall 2005
3,700 - 5,000
3,700 - 5,000
Fall 2006
10,500 -13,000
2,100 - 2,700
Fall 2007
16,420 - 20,795
26,840 - 34,140
Total (Spring Fall)
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Synopsis of on-going work
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Lake Onalaska2005 2007NWHC lead
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Prevalence of Infection

• Overall prevalence for parasites at all sites
  across entire season was 70.75
• Highest prevalence for a parasite was in August
  83.1
• Lowest prevalence for a parasite was in May 54.1

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2006 2007 Management study
T2
C
6 areas at 110 feet
T1
T2
Artificial Island
C
C
T1
T1
Treatments C Control T1 Gravel T2
Gravel/sand mix
T2
3 areas at 90 feet
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Monitoring
Infected snails found in every pool sampled
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2007 Vegetation and Snail Sampling
Pool 8
Pool 13
Pool 8
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2008Pools 7 and 8 study
Example of sampling protocol
Site 2
Site 1
30 cm
60 cm
A
A
B
B
X 2
X 2
Cobble assessment
N
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Snail comparisons between pools
Pool 7
Pool 8
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Infection Rates
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Documented exotic infection patterns
After this summer, additional hosts identified
C. bushiensis
S. globulus
Amnicola
L. polyoon
Campeloma
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C. bushiensis abundance Pool 7
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C. bushiensis abundance Pool 8
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Experimental exposures
Conclusion Bithynia does not appear to be as
susceptible to NATIVE parasite species as native
snail species
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Management Strategies