Concentrations of PCDDs and PCDFs in Eggs and Diets of
Wood Ducks and Hooded Mergansers
2
Fredricks ,
2
Zwiernik ,
2
Tazelaar ,
Lisa L.
Timothy B.
Matthew J.
Dustin L.
Jeremy N.
John P. Giesy2,3, Denise P. Kay4, Rita M. Seston2, Sarah J. Coefield2, Susan Kaelber-Matlock5
1
U.S. Fish and Wildlife Service, East Lansing, MI, USA
3 University of Saskatchewan, Saskatoon, SK, Canada
5 Michigan Department of Environmental Quality, Bay City, MI, USA
2
4
2
Moore ,
Michigan State University, East Lansing, MI, USA
ENTRIX, Inc., East Lansing, MI, USA
METHODS & MATERIALS
ABSTRACT



Previously established nest boxes used for 2003 collections
In 2004, 52 nest boxes placed at 2 reference sites (n=20) and 5 target sites (n=34)
Egg samples collected April-May 2003, 2005 - 2007
 1 fresh egg/nest was collected
 Addled eggs were sampled from abandoned or depredated nests

Two PCDF congeners (2,3,4,7,8-PeCDF and 2,3,7,8-TCDF) accounted for 80 – 90% of
TEQs at target sites.

Median TEQ concentrations for wood duck and hooded merganser eggs were 240 ng/kg
and 1,200 ng/kg, respectively, at target sites and 3 ng/kg and 22 ng/kg, respectively, at reference sites.

Wood duck and hooded merganser egg sample concentrations of 2,37,8-TCDD ranged
from ND to 6 ng/kg and from 49 to 378 ng/kg, respectively, collected from a contaminated
river system in WI [3]


Prey items collected in 2005 - 2007
Chemical analyses followed EPA method 8290


Egg results are expressed in fresh wet weight, corrected for recoveries, and non-detect
congeners were set to ½ detection limit
Wood duck egg sample concentrations of TEQs ranged from 0 to 30 ng/kg collected near a
bleached kraft paper mill in NC where reference eggs were <1 ng/kg [4]

White and Hoffman [5] implicated TEQ egg concentrations of > 20-50 ng/kg with
decreased productivity in a field study of wood ducks in Arkansas, but Augspurger et al. [6]
found no increase in mortality of wood duck eggs injected with 2,3,7,8-TCDD at 4600
ng/kg.

TEQ concentrations are based on avian-specific World Health Organization TCDD
equivalency factors [2]

Concentration of congener i in diet = ∑(fraction dietary component j)(concentration of i in j)
DIET AND BMFs
CONCENTRATIONS IN EGGS
A
Hooded Merganser
Wood Duck
17%
INTRODUCTION
300
2%
25%
40%
17%




57%
Site located in Midland Co, Michigan, USA on the Tittabawassee River (Fig. 1.)
15%
14%
Elevated concentrations of PCDFs and PCDDs present in floodplain soils and
sediments downstream of Midland, MI [1]
12%
250
200
2,3,7,8-TCDF
150
2,3,4,7,8-PeCDF
100
2378-TCDD
50
0
Aq. Invert.
Emergent Aq. Invert
Terr. Insects
Reference areas were upstream (2005-2007) and outside of watershed (2003)
Aq. Plants
Terr. Plants
Mollusc
Crustaceans
Amphians
Fish
Eggs and prey items collected for receptor species of interest: wood duck (Aix
sponsa) and hooded merganser (Lophodytes cucullatus)
A
Em qua
er tic
ge in
nt ve
aq rte
Te ua br a
r re tic tes
st inv
ri
e
Aq a l in rts
Te uat sec
r re ic p ts
st lan
r ia
l p ts
la
M nts
Cr ollu
us sc
ta s
c
Am ea
n
ph s
ib
ia
n
W
O Fi s
h
D
HO U D
M iet
E
Di
et
The Tittabawassee River downstream of Midland, Michigan, is known to be contaminated with
polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). In a 2003 pilot study, eggs from wood
ducks and hooded mergansers were collected from existing nest boxes in the floodplain of the
Tittabawassee River and at a reference location outside of the watershed. The eggs from the
Tittabawassee River had greater concentrations of PCDD/Fs and a different relative congener pattern than
those from the reference area. Based on these results, 20 nest boxes were placed upstream of Midland
and 31 additional nest boxes were placed downstream of Midland within the floodplain of the river. Single
eggs were sampled from clutches located in two upstream reference areas and five downstream target
areas from 2005-2007. Concentrations of the seventeen 2,3,7,8-substituted PCDD/F congeners in eggs
from both studies were converted to TEQs using WHO avian TEF values. One of the target areas used in
the current study was the same as the one used in the pilot study, and eggs sampled there in different
years and analyzed in different laboratories had similar concentrations of total TEQs. Eggs from the
reference area in the pilot study that was outside the watershed appeared to be less contaminated than
those from the upstream reference locations in the current study. In target areas, total TEQs in individual
wood duck eggs ranged from 1.0 to 1500 ng/kg, fresh wet weight, and median TEQs within areas ranged
from 74 to 280 ng/kg. In the reference areas, median TEQs within areas ranged from 1.7 to 24 ng/kg. For
hooded mergansers, TEQs in individual eggs from target areas ranged from 28 to 2200 ng/kg, and median
TEQs within target areas ranged from 380 to 1400 ng/kg. For hooded merganser eggs collected in
reference areas, median TEQs within areas ranged from 12 to 360 ng/kg. As has been observed for other
biota downstream of Midland, two PCDF congeners (2,3,7,8-TCDF and 2,3,4,7,8-PeCDF) contributed
>90% of the TEQs for 60 of 69 eggs from the target areas. The greater concentrations in eggs of hooded
mergansers relative to those of wood ducks was expected from differences in dietary composition, but
BMFs were also greater for hooded mergansers than for wood ducks.
pg/g wet weight
1
Williams ,
Fig. 4. Concentrations of 2,3,7,8-TCDF,
2,3,4,7,8-PCDF and 2,3,7,9-TCDD in
dietary components and overall diets for
Site 6.
Fig. 3. Dietary composition used to
calculate concentrations in diets [7,8]
B
Table 1. Biomagnification factors from diet to eggs (ww/ww)
Rose Lake
Fig. 1. Tittabawassee River study area in Midland Co, Michigan USA with additional reference
area (Rose Lake) in Clinton and Shiawassee Co. Upstream references sites (1 & 2) and
downstream target sites (3-7) are indicated.
2,3,7,8-TCDF 2,3,4,7,8-PeCDF
Fig. 2. TEQs (ng/kg) collected in the Tittabawassee River floodplain (A – wood
duck, B – hooded merganser).
Wood duck
Site 5
Wood duck
Site 6
Hooded Merganser
Site 5
Hooded Merganser
Site 6
2,3,7,8-TCDD
3.4
3.6
4.2
1.9
1.1
2.7
7.8
20
3.8
4.2
9.2
3.2
National Food Safety and Toxicology Center
CONCLUSIONS

Target area TEQ concentrations were greater than concentrations in reference areas and in
other field collected wood duck egg samples.


TEQ concentrations in hooded merganser eggs were greater than in wood duck eggs.

Biomagnification factors from diet to egg were greater for hooded mergansers than for wood
ducks for TCDF, PeCDF, and TCDD, with dietary concentrations calculated from measured
concentrations in local food items and dietary compositions from the literature.
Target area TEQ concentrations were greater than those implicated in White and Hoffman [5]
as causing decreased productivity in wood ducks, but all were less than a wood duck NOAEL
for embryo mortality from TCDD in an egg injection study.
L I T E R AT U R E C I T E D
1. Hilscherova et al. 2003. Polychlorinated dibenzo-p-dioxin and dibenzofuran concentration profiles in sediments
and flood-plain soils of the Tittabawassee River, Michigan. Environmental Science and Technology 37:468-474.
2. Van den Berg et al. 1998. Toxic equivalency factors (TEFs) for PCBs, PCDDs, PCDFs for humans and wildlife.
Environmental Health Perspectives 106:775-792.
3. Custer et al. 2002. Dioxins and congener-specific polychlorinated biphenyls in three avian species from the
Wisconsin River, Wisconsin. Environmental Pollution 119:323-332.
4. Augspurger et al. 2008. Accumulation of environmental contaminants in wood duck (Aix sponsa) eggs with
emphasis on polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans. Archives of Environmental
Contamination and Toxicology 55:670-682.
5. White and Hoffman. 1995. Effects of polychlorinated dibenzo-p-dioxins and dibenzofurans on nesting wood ducks
(Aix sponsa) at Bayou Meto, Arkansas. Environmental Health Perspectives 103(Supplement 4):37-39.
6. Augspurger et al. 2008. Embryo toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin to the wood duck (Aix sponsa). Archives of Environmental Contamination and Toxicology
55:659-669, 2008.
7. Drobney 1990. Nutritional ecology of breeding wood ducks: A synopsis for wetland management. In: Proceedings of the 1988 North American Wood Duck Symposium,
edited by L. H. Fredrickson et al., p. 77-82.
8. Dugger et al. 1994. Hooded merganser (Lophodytes cucullatus). In: The Birds of North America, edited by A. Poole and F. B. Gill, p. 1-24.
ACKNOWLEDGEMENTS
We would like to thank all field/laboratory personnel that helped with this project, especially the following: David
Hamman, Michael Kramer, Jim Dastyck, Ed DeVries, Sharon Hanshue, Arianne Neigh, Karl Strause, Bretton and
Carrie Joldersma, Cyrus Park, Mike Fales, Meghan Mikesell, Ben Nessia, Jiachun Ge, Lam Wong, Mick Kramer,
Patrick Bradley, Melissa Shotwell, Emily Koppel, Melissa Palmer, Cassie Steiler, Bethany Opperman, William
Sterling, Lacy Sharrard, Sandy Mazzoni, and Kelly Winchell. Additionally, this study would not have been possible
without the dedicated team of the employees at Entrix, Inc., East Lansing, MI and wonderful support staff at
Michigan State University. Funding was provided by Michigan DEQ and through an unrestricted grant from The
Dow Chemical Company to Michigan State University.