Risks to Insectivorous Birds in the Calumet Region from Transfer of Contaminants from Sediments to

Emergent Aquatic Insects

S. Gallo1, D. Soucek1, J. Levengood1, W. Hill1

and G. Bordson2 1Illinois Natural History Survey, Champaign IL; 2Illinois

Sustainable Technology Center, Champaign IL;

Funding: The Illinois Waste Management and

Research Center, WMRC (ISTC)

Department of Natural Resources and Environmental Sciences, UIUC

Center for Ecological Entomology, INHS

Overall Objectives• Observational study to quantify contaminant

loads in sediments, aquatic insects and tree swallow eggs and nestlings in Calumet, IL.

• Attempt to understand the movement of contaminants between aquatic and terrestrial ecosystems

• Use stable isotope analysis to try to determine the source of the contaminants

Contaminants in sediments or water

Contaminant Transfer Between Ecosystems:

Tachycineta bicolor

Photo: John Marlin

Sites

• 2 Contaminated Sites– Big Marsh– Indian Ridge

• 1 “Reference” Site– Powderhorn Lake– No record of contaminants

• 30 Nest boxes at each site

Big Marsh

Indian Ridge

Powderhorn Lake

N

ProceduresCollected in 2004 & 2005:

Birds: Tree Swallows (Tachycineta bicolor)• 2 eggs from each of 10 nests

• 1 14-day-old nestling from same 10 nests

Insects:• Emergence traps

• Benthic samples

• Bolus material (analyzed for contaminants in 2005 only)

Sediment grabs

Analyses

12 priority elements measured: Ag, As, Ba, Cd, Co, Cr, Cu, Hg, Ni, Pb, Se, Zn.

Approximately 60 different Organics measured:

PCBs, PBDEs, DDTs and Other organo-chlorine pesticides

Nesting Ecology

115

120

125

130

135

140

BM IRM PL

Site

Julia

n d

ate

com

ple

ted

nes

t 2004

2005

* *

-No differences among sites in # nestlings /nest, nest success, hatch success, fledge success. Nest success ranged from 69 to 83%.

-Mass of nestlings at BM and IRM were significantly lower than at PL. Related to greater # eggs/nest (BM > PL in 2004).

Site Vegetation

Percent Canopy Cover

0

10

20

30

40

50

60

70

Big Marsh Indian Ridge Reference

• Reference Site: approximately 2x more canopy cover

Orthogonal contrasts comparing to Reference: ** <0.01, *<0.05

* **

Diet

0

0.2

0.4

0.6

0.8

1

1.2

1.4

Big Marsh Indian Ridge PowderhornLake

Dry

mas

s (g

)

Aquatic

Terrestrial

Total mass of aquatic or terrestrial arthropods represented in the 2005 boluses. N= 61, 26, 25 for Big Marsh, Indian Ridge and Powderhorn, respectively.

Contaminants

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

egg Nestling Insects

Big Marsh

Indian Ridge

Powderhorn Lake

Mercury accumulation

*** **

Orthogonal contrasts comparing to Reference: *** <0.0001, *<0.05

Growth dilution with no addition

mg/

kg to

tal H

g dr

y w

t

Synthesizing Ecology and Contaminant Data:Nest Initiation and Egg Hg levels

mg/kg Hg dry wt

0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40

Julia

n da

te o

f fi

rst e

gg la

id

120

130

140

150

160

170

BM 2004BM 2005IR 2004IR 2005PL 2004PL 2005Plot 1 Regr

Contaminant Transfer Pathways: Local and Migratory

Local

Migratory

http://www.birdnature.com/flyways.html

-Eggs form ~6 days before laying-Hg half-life in other birds is 40 to 84 days-swallows arrive 14-28 days before laying-at least some Hg in eggs must be from non-local sources

4,4’-DDD in eggs and nestlings

0

500

1000

1500

2000

2500

BM IRM PL

Site

4,4'

-DD

D in

egg

s (n

g/g

dw

) 2004

2005* *

*

4,4’-DDD in eggs and nestlings

0

500

1000

1500

2000

2500

BM IRM PL

Site

4,4'

-DD

D in

egg

s (n

g/g

dw

) 2004

2005* *

*

0

200

400

600

800

1000

1200

1400

1600

BM IRM PL

Site

4,4'

-DD

D in

nes

tlin

gs (

ng/

g d

w)

2004

2005*

*

PBDEs in eggs and nestlings

0

100

200

300

400

500

600

700

800

BM IRM PL

Site

sum

PB

DE

s in

egg

s (n

g/g

dw) 2004

2005

PBDEs in eggs and nestlings

0

100

200

300

400

500

600

700

800

BM IRM PL

Site

sum

PB

DE

s in

egg

s (n

g/g

dw) 2004

2005

0

50

100

150

200

250

300

350

400

450

BM IRM PL

Site

sum

PB

DE

s in

nes

tlin

gs (

ng/g

dw

)

2004

2005

*

PBDEs in eggs

PBDEs in nestlings

Contaminant sources

Stable Isotopes

• Measure of light to heavy C and N isotope ratios

• C13/C12 ratio in organisms changes very little w/ increasing trophic level and can indicate percentage of sources/prey items that are being consumed

• N15/N14 ratio can indicate trophic level. N15 increases with trophic level because consumers excrete N14 at a faster rate

• Both can provide insight into long term food resource use rather than short term use (i.e. gut content analyses)

• Expressed as 15N and 13C -- ratio of isotopes in sample relative to ratio in standards (air for N, and Pee Dee Belamite for C).

Stable Isotopes

• Measure of light to heavy C and N isotope ratios

• C13/C12 ratio in organisms changes very little w/ increasing trophic level and can indicate percentage of sources/prey items that are being consumed

• N15/N14 ratio can indicate trophic level. N15 increases with trophic level because consumers excrete N14 at a faster rate

• Both can provide insight into long term food resource use rather than short term use (i.e. gut content analyses)

• Expressed as 15N and 13C -- ratio of isotopes in sample relative to ratio in standards (air for N, and Pee Dee Belamite for C).

0

2

4

6

8

10

12

14

16

18

-30 -25 -20 -15 -10

δ13

C

δ15N

fish

periphyton

other invertebratescrayfish

FPOM

leaf litter

Stable Isotope profiles of bolus insects

Big Marsh Aquatic Terrestrial

15N 13.65 14.60

13C -27.65 -25.77

Indian Ridge Aquatic Terrestrial

15N 20.46 8.64

13C -25.07 -25.72

Powderhorn Aquatic Terrestrial

15N 4.48 5.44

13C -26.06 -25.65

Big Marsh

y = -128.28x - 2738.8

R2 = 0.5696

300

400

500

600

700

800

900

1000

-28.00 -27.50 -27.00 -26.50 -26.00 -25.50 -25.00 -24.50 -24.00

δ13C

sum

PC

Bs

terrestrial

aquatic

Sources of contaminantsSite Correlation associated withBig Marsh

PCBs 44, 52, 105 higher 15N, less negative 13C terrestrial

PCB 70 less negative 13C terrestrial

PCB 194 lower 15N aquatic

DDE more negative 13C aquatic

PBDE 49, 47, 85, 99, 100 higher 15N terrestrial

Indian Ridge

PCB 52 lower 15N terrestrial

PCB 77 lower 15N, more negative 13C terrestrial

PCB 95, 153 more negative 13C terrestrial

Chlordane and Dieldrin more negative 13C terrestrial

PBDE 28 more negative 13C terrestrial

PBDE 47 higher 15N aquatic

Powderhorn

Hg lower 15N aquatic

PCB 31, 70, 95, 99, 110, 194, 201 higher 15N terrestrial

PBDE 71, 47, 99, 85, 154 less negative 13C terrestrial

Conclusions

• Tree Swallows in Calumet are accumulating a variety of contaminants through their diet

• Site differences exist • Contaminant may be acquired from terrestrial sources

more so than aquatic sources• Tree swallows prefer to nest at BM and IRM,

potentially risking greater exposure to contaminants

Questions?

PCBs in eggs and nestlings

0

2000

4000

6000

8000

10000

12000

BM IRM PL

Site

sum

PC

Bs

in e

ggs

(ng/

g dw

) 2004

2005

**

PCBs in eggs and nestlings

0

2000

4000

6000

8000

10000

12000

BM IRM PL

Site

sum

PC

Bs

in e

ggs

(ng/

g dw

) 2004

2005

**

0

100

200

300

400

500

600

700

800

900

BM IRM PL

Site

sum

PC

Bs

in n

estl

ings

(ng

/g d

w)

2004

2005

**