Upper Midwest Environmental Sciences Center Mortality of waterbirds in the Upper Mississippi River Jennifer Sauer; USGS—La Crosse, Wisconsin Dr. Rebecca

Upper Midwest Environmental Sciences Center

Mortality of waterbirds Mortality of waterbirds in the in the

Upper Mississippi RiverUpper Mississippi River

Mortality of waterbirds Mortality of waterbirds in the in the

Upper Mississippi RiverUpper Mississippi River

Jennifer Sauer; USGS—La Crosse, WisconsinDr. Rebecca Cole; USGS—Madison, WisconsinDr. Greg Sandland, UW-La CrosseDr. Roger Haro, UW-La CrosseJim Nissen; USFWS La Crosse DistrictEd Britton; USFWS Savanna District

Jennifer Sauer; USGS—La Crosse, WisconsinDr. Rebecca Cole; USGS—Madison, WisconsinDr. Greg Sandland, UW-La CrosseDr. Roger Haro, UW-La CrosseJim Nissen; USFWS La Crosse DistrictEd Britton; USFWS Savanna District



Waterbird MortalitiesWaterbird Mortalities


Mortality EventsMortality Events

19982006-81992

1996-P

2002-P

2007

2001-4



Bithynia tentaculataBithynia tentaculata


Cyathocotyle bushiensis (Coots)Cyathocotyle bushiensis (Coots)Sphaeridiotrema globulus (Scaup, Coots)Sphaeridiotrema globulus (Scaup, Coots)Leyogonimus polyoon (Coots)Leyogonimus polyoon (Coots)


PathologyPathology

SphaeridiotremaSphaeridiotrema– reside in the small intestinereside in the small intestine– feed on blood, causing severe blood loss and feed on blood, causing severe blood loss and

anemiaanemia CyathocotyleCyathocotyle

– reside in the cecareside in the ceca– cause a disruption in water and electrolyte balancecause a disruption in water and electrolyte balance

Leyogonimus polyoonLeyogonimus 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


Why are we concerned?Why are we concerned?


Why are we concerned?Why are we concerned?


Total Mortality EstimatesTotal Mortality Estimates

16,420 - 20,79516,420 - 20,79526,840 - 34,140 26,840 - 34,140 Total (Spring & Fall)Total (Spring & Fall)10,500 -13,000 10,500 -13,000 2,100 - 2,700 2,100 - 2,700 Fall 2007Fall 20073,700 - 5,0003,700 - 5,0003,700 - 5,0003,700 - 5,000Fall 2006Fall 2006150 - 200150 - 2005,300 - 7,0005,300 - 7,000Fall 2005Fall 200510-1510-152,100 - 2,600 2,100 - 2,600 Fall 2004Fall 2004

6,100 - 7,6006,100 - 7,600Fall 2003Fall 200350 - 6550 - 65580 - 700580 - 700Fall 2002Fall 2002

Pool 8Pool 8Pool 7Pool 7


Synopsis of on-going workSynopsis of on-going work


Lake Onalaska—2005 & 2007Lake Onalaska—2005 & 2007NWHC leadNWHC leadLake Onalaska—2005 & 2007Lake Onalaska—2005 & 2007NWHC leadNWHC lead


Prevalence of InfectionPrevalence of Infection

Overall prevalence for parasites at all sites Overall prevalence for parasites at all sites across entire season was 70.75%across entire season was 70.75%

Highest prevalence for a parasite was in August Highest prevalence for a parasite was in August 83.1%83.1%

Lowest prevalence for a parasite was in May Lowest prevalence for a parasite was in May 54.1%54.1%


Treatments

C = ControlT1 = GravelT2 = Gravel/sand mix

T2

T1

C

C

T1

T2

3 areas at ~90 feet

6 areas at 110 feet

C

T1

T2

2006 & 2007 Management study2006 & 2007 Management study2006 & 2007 Management study2006 & 2007 Management study


MonitoringMonitoringMonitoringMonitoring

Infected snails found in every pool sampled


Pool 8

2007 Vegetation and Snail Sampling2007 Vegetation and Snail Sampling2007 Vegetation and Snail Sampling2007 Vegetation and Snail Sampling

Pool 131 – 5

6-100

>100 <1000

>1000

Pool 8


Example of sampling protocol

Site 1Site 2

X 2X 2

30 cm 60 cmABA B

N

Cobble assessment

2008—Pools 7 and 8 study2008—Pools 7 and 8 study2008—Pools 7 and 8 study2008—Pools 7 and 8 study


Snail comparisons between poolsSnail comparisons between pools

BithyniaAmnicolaPhysaOther

Pool 7 Pool 8


Snail samples by transectGroup average

E1-

E-A

CB

I-N-B

CB

I-N-A

CB

I-S-A

CB

I-S-B

N1-

S-B

N1-

S-A

CO

-E-A

CO

-E-B

AH

-E-A

AH

-E-B

BG

-E-B

CO

-W-A

AH

-W-A

AH

-W-B

CO

-W-B

RO

-N-B

E1-

E-B

RO

-S-A

RO

-S-B

RO

-N-A

TI-S

-BE

1-W

-AT

I-S-A

BG

-E-A

E1-

W-B

N1-

N-A

N1-

N-B

BG

-W-A

BG

-W-B

TI-N

-AT

I-N-B

Samples

100

80

60

40

Sim

ilarit

y

Transform: Square rootResemblance: S17 Bray Curtis similarity


0

1

2

3

4

5

6

7

8

9

0 10 20 30 40

Mean host density

Me

an

ab

un

da

nc

eR2 = 0.88; P = 0.014

Infection RatesInfection Rates


Documented exotic infection patterns Documented exotic infection patterns

B. tentaculata

C. bushiensis

S. globulus

L. polyoon

After this summer, additional hosts identified:After this summer, additional hosts identified:

C. bushiensis

S. globulus

L. polyoon

Amnicola

Campeloma


C. bushiensis abundance – Pool 7C. bushiensis abundance – Pool 7

0

2

4

6

8

10

12

AH-East AH-West BG-East BG-West CO-East CO-West RO-North RO-South

Site

Me

an

C. b

us

hie

ns

is a

bu

nd

an

ce Amnicola

Bithynia


C. bushiensis abundance – Pool 8C. bushiensis abundance – Pool 8

0

2

4

6

8

10

12

E1-East E1-West CBI-North CBI-South T1-North T1-South N1-North N1-South

Site

Me

an

C. b

us

hie

ns

is a

bu

nd

an

ce

AmnicolaBithynia


0

0.2

0.4

0.6

0.8

1

Bt Pg Le Ht

Snail species

Pro

po

rtio

n i

nfe

cted

(ec

hin

ost

om

e)

0

0.2

0.4

0.6

0.8

1

Bt Pg Le Ht

Snail species

Pro

po

rtio

n in

fect

ed (

S. g

lob

ulu

s)

Experimental exposuresExperimental exposures

Conclusion: Conclusion: BithyniaBithynia does not appear to be as does not appear to be as susceptible to NATIVE parasite species as susceptible to NATIVE parasite species as native snail speciesnative snail species


Management Management Strategies Strategies

Molluscacide; Molluscacide;

Decrease rip rap (rocks)Decrease rip rap (rocks)

Harvest submersed vegetationHarvest submersed vegetation

Harass birds??Harass birds??

Cover rip-rapCover rip-rap

Modify island designModify island design

Pick up dead birdsPick up dead birds

X

XX

XX

Documents

Upper Midwest Environmental Sciences Center Mortality of waterbirds in the Upper Mississippi River Jennifer Sauer; USGS—La Crosse, Wisconsin Dr. Rebecca