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
Contaminant Transfer
Between Ecosystems:
Tachycineta bicolor
Contaminants in sediments or water
Photo: John Marlin
Sites
• 2 Contaminated Sites
– Big Marsh
– Indian Ridge
• 30 Nest boxes at
each site
Big Marsh
• 1 “Reference” Site
Indian Ridge
– Powderhorn Lake
– No record of contaminants
Powderhorn
Lake
N
Procedures
Collected 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
Julian date completed nest
140
2004
135
2005
130
*
*
125
120
115
BM
IRM
PL
Site
-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
• Reference Site: approximately 2x more canopy cover
Percent Canopy Cover
70
60
*
**
Big M arsh
Indian Ridge
50
40
30
20
10
0
Orthogonal contrasts comparing to Reference: ** <0.01, *<0.05
Reference
Diet
1.4
Aquatic
Dry mass (g)
1.2
Terrestrial
1
0.8
0.6
0.4
0.2
0
Big Marsh
Indian Ridge
Powderhorn
Lake
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
Mercury accumulation
0.35
mg/kg total Hg dry wt
0.3
***
*
*
0.25
Big M arsh
0.2
Indian Ridge
0.15
Powderhorn Lake
0.1
0.05
Growth dilution
with no addition
0
egg
Nestling
Insects
Orthogonal contrasts comparing to Reference: *** <0.0001, *<0.05
Synthesizing Ecology and Contaminant Data:
Nest Initiation and Egg Hg levels
170
Julian date of first egg laid
160
150
140
130
120
0.05
0.10
0.15
0.20
0.25
mg/kg Hg dry wt
BM 2004
BM 2005
IR 2004
IR 2005
PL 2004
PL 2005
Plot 1 Regr
0.30
0.35
0.40
Contaminant Transfer Pathways:
Local and Migratory
Local
Migratory
-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
http://www.birdnature.com/flyways.html
4,4’-DDD in eggs and nestlings
4,4'-DDD in eggs (ng/g dw)
2500
*
2000
2004
2005
*
1500
1000
*
500
0
BM
IRM
Site
PL
4,4’-DDD in eggs and nestlings
*
1500
1000
500
0
2004
2005
*
2000
4,4'-DDD in nestlings (ng/g dw)
4,4'-DDD in eggs (ng/g dw)
2500
1600
1400
2004
2005
*
1200
1000
*
800
600
BM 400
200
*
IRM
PL
Site
0
BM
IRM
Site
PL
PBDEs in eggs and nestlings
sum PBDEs in eggs (ng/g dw)
800
2004
700
2005
600
500
400
300
200
100
0
BM
IRM
Site
PL
PBDEs in eggs and nestlings
2004
700
2005
600
500
400
300
200
100
0
BM
sum PBDEs in nestlings (ng/g dw)
sum PBDEs in eggs (ng/g dw)
800
450
400
2004
350
2005
300
250
200
150
IRM
100
Site
PL
*
50
0
BM
IRM
Site
PL
PBDE 2005 Eggs
PBDEs in eggs
250
BigMarsh
Indian Ridge
Powderhorn
ng/g dry wt
200
150
100
50
0
3
8
9
7
6
7
5
4
3
8
9
0
E #1 DE #2 BDE #4 BDE #4 BDE #6 E #10 DE #9 BDE #8 E #15 DE #15 DE #13 E #18
D
D
D
B
B
e
e
e
e
B
B
P
T
T
T
Tr
Pe
Hx
Hx
PeB
HxB
HpB
D
TrB
PBDE Congener
PBDEs in nestlings
05 nestling pbde profile
200
190
BigMarsh
Indian Ridge
Powderhorn
ng/g dry wt
75
50
25
0
Tr 17
Tr 28
Te 49
Te 71 TeB 47 Te 66 Pe 100 Pe 99
Pe 85 Hx 154 Hx 153 Hx 138 Hp 183 De 209
PBDE Congener
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 Cfish
and N isotope ratios
18
16
δ N
14
• C13/C12 ratio crayfish
in organisms changes very little w/ increasing trophic level and
other
invertebrates items that are being consumed
12
can indicate percentage
of sources/prey
15
• N15/N14
ratio can indicate trophic level. N15 increases with trophic level
periphyton
because consumers excrete N14 at
a faster rate
FPOM
10
8
6
• Both can provide insight into long term food resource use rather than
short term use (i.e. gut content analyses)
4
2
leaf litter
0
• Expressed as 15N and 13C -- ratio of isotopes in sample relative to ratio in
-30
-25
-20
-15
-10
standards (air for N, and Pee Dee Belamite for C).
δ13 C
Stable Isotope profiles of bolus insects
Big Marsh
Aquatic
Terrestrial
15N
13C
13.65
-27.65
14.60
-25.77
Indian Ridge Aquatic
Terrestrial
15N
13C
8.64
-25.72
20.46
-25.07
Powderhorn Aquatic
Terrestrial
15N
13C
5.44
-25.65
4.48
-26.06
Big Marsh
1000
y = -128.28x - 2738.8
900
2
sum PCBs
R = 0.5696
aquatic
800
700
600
500
terrestrial
400
300
-28.00 -27.50 -27.00 -26.50 -26.00 -25.50 -25.00 -24.50 -24.00
δ13C
Sources of contaminants
Site
Big Marsh
Correlation
PCBs 44, 52, 105
higher  N, less negative  C
terrestrial
13
terrestrial
PCB 70
PCB 194
associated with
15
13
less negative  C
15
lower  N
aquatic
13
DDE
more negative  C
PBDE 49, 47, 85, 99, 100
higher 15 N
terrestrial
PCB 52
lower 15 N
terrestrial
PCB 77
lower 15 N, more negative 13 C
terrestrial
PCB 95, 153
more negative 13 C
terrestrial
aquatic
Indian Ridge
Chlordane and Dieldrin
13
terrestrial
13
terrestrial
more negative  C
PBDE 28
more negative  C
PBDE 47
higher  N
15
aquatic
15
aquatic
15
terrestrial
Powderhorn
Hg
lower  N
PCB 31, 70, 95, 99, 110, 194, 201 higher  N
PBDE 71, 47, 99, 85, 154
13
less negative  C
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
sum PCBs in eggs (ng/g dw)
12000
2004
10000
2005
8000
6000
*
4000
*
2000
0
BM
IRM
Site
PL
PCBs in eggs and nestlings
2004
10000
2005
8000
900
6000
4000
2000
0
sum PCBs in nestlings (ng/g dw)
sum PCBs in eggs (ng/g dw)
12000
800
*
*
* 700
BM
2004
2005
*
600
500
400
300
IRM
PL
200
100
Site
0
BM
IRM
Site
PL