Bald Eagle Contaminant Exposure Data

I.

Organochlorine Contamination

A.

Concentrations in Adults, Juveniles, and Nestlings

1.

Forty-five bald eagles were found sick or dead in 18 states and Canada from 1964-65 (Reichel et al., 1969a). DDE occurred at median concentrations in 1964 and 1965 of 8.90 and 7.80 µg/g wet weight in carcass, 4.91 and 5.15 µg/g in liver, and 1.37 and 1.00 µg/g in brain. Median DDD values were 0.44 and 1.60 µg/g in carcass, 0.54 and 0.60 µg/g in liver, and 0.40 and 0.16 µg/g in brain. Median concentrations of dieldrin were 0.33 and 0.65 µg/g in carcass, 0.21 and 0.35 µg/g in liver, and 0.08 and 0.10 in brain. Median concentrations of DDT, heptachlor epoxide, endrin, and 4,4'-dichlorobenzophenone were <0.5 µg/g in all tissues analyzed.

2.

Two eagles near death were collected from Newton, Connecticut, and Belleview, Florida in 1967 and 1968, respectively (Reichel et al., 1969b). The adult eagle from Florida had DDE concentrations of 28.9 µg/g wet weight in carcass, 73.8 µg/g in liver, and 27.1 µg/g brain. Other contaminants detected at elevated levels were DDD (5.9 µg/g carcass, 10.2 µg/g liver, 3.8 brain), dieldrin (6.5 µg/g carcass, 15.7 µg/g liver, 7.0 µg/g brain), and DDD olefin (2.9 µg/g carcass, 3.6 µg/g liver, 2.8 µg/g brain). Concentrations of DDT, heptachlor epoxide, endrin, and 4,4-dichlorobenzophenone were <1.0 µg/g and o,p’-DDT was not detected. The immature female from Connecticut had DDE concentrations of 263.0 µg/g wet weight in carcass, 170.0 µg/g in liver, and 88.6 µg/g brain. Other contaminants detected at elevated concentrations were DDD (79.2 µg/g carcass, 76.2 µg/g liver, 14.4 brain), DDT (14.1 µg/g carcass, 0.8 µg/g liver, 20.3 brain), dieldrin (5.3 µg/g carcass, 5.2 µg/g liver, 2.3 µg/g brain), DDD olefin (11.6 µg/g carcass, 7.1 µg/g liver, 2.7 µg/g brain), and 4,4-dichlorobenzophenone (3.5 µg/g carcass, 2.6 µg/g liver, ND in brain). Concentrations of o,p’-DDT were <1.0 µg/g and heptachlor epoxide and endrin were not detected.

3.

From 1966 through 1970, 108 bald eagles found either dead or moribund throughout the United States were analyzed for contaminants (Mulhern et al., 1970; Belisle et al, 1972). Median concentrations of DDE in the carcass were greatest in 1970 at 18 µg/g wet weight and lowest in 1968 at 4.92 µg/g. Concentrations of DDD in carcass were also greatest in 1970 at 1.5 µg/g and lowest in 1968 at 0.85 µg/g. DDT, dieldrin, heptachlor epoxide, and dichlorobenzophenone in carcass were <1 µg/g for all years studied, excluding 1966 when levels reached 1.20 µg/g for dichlorobenzophenone. DDE concentrations in brain were greatest in 1970 at 26 µg/g wet weight and lowest in 1968 at 0.92 µg/g. Concentrations of DDD in brain were also greatest in 1970 at 1.5 µg/g. Concentrations of DDT, dieldrin, heptachlor epoxide, and dichlorobenzophenone in brain were all <1 µg/g. The only exception was dieldrin, in 1970, found at a median concentration of 2.0 µg/g. PCB in brain ranged from 0.20 µg/g in 1966 to 46 µg/g in 1970.

4.

During a 1967-1972 reproductive study in northwestern Ontario, a dead 5-6 week old eagle nestling was collected (Grier, 1974). DDT was detected only in the liver at a concentration of 0.05 µg/g dry weight. All other organochlorine contaminants were detected in the brain, liver, and breast muscle. Contaminant levels, respectively, were: 5.30, 8.72 , and 1.59 µg/g DDE; 0.20, 0.41, and 0.04 µg/g DDD; 0.40, 0.45, and 0.09 µg/g dieldrin; and 1.80, 5.97, and 1.14 µg/g PCB.

5.

Bald eagle liver, carcass, and egg samples were collected during 1968-76 in Maryland and Virginia (Stafford et al., 1978). Kepone was detected in all six eagle livers from Virginia (0.2-16.0 µg/g wet weight) and three of the carcasses (0.1-2.2 µg/g). In Virginia, kepone was detected in seven of eight livers (0.13-130.0 µg/g) and four of the carcasses (0.24-44.0 µg/g). Three eggs collected from the Potomac River, Virginia, in 1976, contained a median (range) kepone concentration of 0.15 (0.14-0.19) µg/g based on total egg volume.

6.

A bald eagle nestling collected between 1969 and 1972 from Lake Ontario contained geometric mean DDE and PCB concentrations, respectively, in the following matrices: brain, 5.32 and 1.82 µg/g dry weight; liver, 8.72 and 5.97 µg/g, and breast muscle, 1.59 and 1.12 (Gilbertson and Reynolds, 1974).

7.

In 1971 and 1972, 37 bald eagles were found dead throughout the United States (Cromartie et al., 1975). Concentrations of organochlorine contaminants in carcass were 0.77-210.0 µg/g DDE, 0.10-33.0 µg/g DDD, 0.12-3.2 µg/g DDT, 0.01- 33 µg/g dieldrin, 0.06-5.5 µg/g heptachlor epoxide, 0.06-1.3 µg/g mirex, 0.18-1.4 µg/g oxychlordane, 0.11-7.4 µg/g cis-chlordane, 0.30 to 1200 µg/g PCB, and <1 µg/g cis-nonachlor, and HCB. Concentrations in brain were 0.07-89.0 µg/g DDE, 0.05-9.9 µg/g DDD, 0.05-0.034 µg/g DDT, 0.05-7.8 µg/g dieldrin, 0.05-1.7 µg/g heptachlor epoxide, 0.05-1.7 µg/g cis-chlordane, 0.10-190.0 µg/g PCB, and <1 µg/g mirex, oxychlordane, cis-nonachlor, and HCB.

8.

Contaminant concentrations were compared between the brain and the carcass (after removal of the skin, beak, feet, gastrointestinal tract, and liver) in 101 bald eagles collected from 1971-74 (location not specified in paper) (Barbehenn and Reichel, 1981). Mean concentrations for the brain (µg/g wet weight) and the carcass (µg/g lipid weight) were as follows: 0.44 and 74 DDD, 1.66 and 200 DDE, 0.22 and 24 mirex, 0.29 and 30 cis-nonachlor, 3.75 and 380 PCB, 0.15 and 15 toxaphene, 0.15 and 15 oxychlordane, 0.27 and 27 cis-chlordane, 0.23 and 20 heptachlor epoxide, 0.54 and 41 dieldrin, 0.40 and 25 DDT, and 0.15 and 8 HCB. It was determined that brain levels could be predicted from the carcass concentration and that the compounds varied by a factor of about 3 in the degree to which they accumulated in the brain

9.

From 1973 to 1974, 86 bald eagles found dead or moribund were collected throughout the United States (Prouty et al., 1977). DDE was highest in the carcass in 1973 at a median concentration of 12.0 µg/g wet weight and in the brain in 1974 at a median concentration of 8.6 µg/g. In 1973, TDE was detected at a median concentration of 1.4 µg/g in the carcass and 1.0 µg/g in the brain. Also in 1973, dieldrin was detected at 1.3 µg/g in the brain. PCBs were highest in 1974 at a median concentration of 50 µg/g in the carcass. Brain PCB concentrations reached a maximum in 1973 with a median level of 7.5 µg/g.

10.

In 1975 a bald eagle was collected from South Dakota (Call et al., 1977). Concentrations of organochlorine contaminants were < 1 µg/g wet weight in the liver. PCBs concentration in liver were 3.83 µg/g.

11.

In 1975, an immature bald eagle was found dead in Illinois (Collier et al., 1976). DDE concentrations were highest in muscle at 3.04 µg/g. Concentrations of other contaminants were highest in the liver at 3.01 µg/g DDD, 2.30 µg/g DDT, 3.12 µg/g dieldrin and 74.1 µg/g total PCBs.

12.

An immature bald eagle found in western Maryland with suspected Pb poisoning contained 0.5 µg/g DDE and 0.53 µg/g PCB in the carcass (Jacobson et al., 1977).

13.

Organochlorine concentrations were measured in blood of nesting bald eagles in southcentral Oregon (Frenzel, 1985). In nestlings, concentrations of DDE, DDD, and PCBs were <1 µg/g. In adults and subadults, concentrations of DDE ranged from 0.08 to 1.4 µg/g and 0.06 to 0.20 µg/g, respectively, DDD and PCBs were <1 µg/g, and cis-chlordane was not detected. Concentrations of trans-nonachlor were <1 µg/g in for all groups. Blood samples were also collected from eagles wintering in Oregon. Mean concentrations of DDE and PCBs were <1 µg/g.

14.

From 1975 to 1977, 168 bald eagles were collected from 29 states in the United States (Kaiser et al., 1980). DDE was detected at its greatest median concentration of 6.8 µg/g wet weight in a carcass collected in 1976. Other organochlorine contaminants were detected in the brain and the carcass at median concentrations of <1 µg/g. Median concentrations of PCBs were greatest in 1976 at 12.0 µg/g in carcasses and 2.2 µg/g brain.

15.

In 1977 and 1978, plasma samples were collected from adult and subadult bald eagles in Colorado and Missouri and (Henny et al., 1981). Concentrations of total DDT, dieldrin, and PCBs were <1 µg/g.

16.

16. From 1978 to 1981, 239 bald eagles found dead or moribund were collected from 32 states in the United States (Reichel et al., 1984). DDE concentrations were highest in 1980 at a of 3.3 µg/g wet weight in carcass and 1.3 µg/g in brain. Concentrations of DDD, DDT, dieldrin, heptachlor epoxide, oxychlordane, cis-chlordane, trans-nonachlor, cis-nonachlor, endrin, toxaphene, HCB, and mirex were <1 µg/g. PCB concentrations were highest in 1979 at 5.3 µg/g in carcass and 1981 at 3.2 µg/g in brain.

17.

Contaminant concentrations were measured in blood and tissues of bald eagles wintering in the Klamath basin, Oregon and California, between 1979 and 1982 (Frenzel and Anthony, 1989). Geometric mean concentrations in adults and subadults in blood were 0.042 and 0.030 µg/g wet weight DDE, and 0.018 and 0.014 µg/g PCB. DDE concentrations in the carcass, adults and subadults together, ranged from 0.19-9.0 µg/g. DDD, dieldrin, heptachlor epoxide, oxychlordane, trans-nonachlor, cis-nonachlor, toxaphene, HCB, and mirex were detected in a portion of the carcasses, at concentrations 0.22 µg/g. PCB was detected in 9 of 10 carcasses, at concentrations ranging from 0.3-10.0 µg/g.

18.

In 1984-1986, organochlorines were measured in 8 bald eagles between 5 weeks and 6 months of age nesting in Lake Superior and inland Wisconsin (Kozie and Anderson, 1991). Concentrations of p,p'-DDE were 1.5-16.0 µg/g wet weight in brain and 0.12-6.6 in breast muscle in Lake Superior, and <1 µg/g in inland colonies. PCB concentrations ranged from 2.9-42.0 µg/g in brain and 0.27-14.0 in breast muscle in Lake Superior and were <1 µg/g in inland colonies. Concentrations of o,p'-DDT, o,p'-DDD, p,p'-DDD, dieldrin, and endrin were <1 µg/g at all locations.

19.

From 1979 to 1981 concentrations DDE and PCBs were <1 µg/g wet weight in blood of bald eagles from Oregon, northern California, and Montana (Wiemeyer et al., 1989).

20.

Blood was collected from 15 nestlings, 4 subadults, and 3 adults nesting in the Columbia River estuary from 1984 to 1986 (Anthony et al., 1993). Mean DDE concentrations were lowest in the nestlings (0.05 µg/g wet weight) and highest in the adults (2.13 µg/g). Mean PCBs were also lowest in the nestlings (0.04 µg/g) and highest in the adults (2.40 µg/g).

21.

From 1985-1993, low concentrations of four organochlorines were found in the blood of 18 migrant adult and immature eagles in west-central Montana (Harmata and Restani, 1995). Maximum DDE, DDD, dieldrin, and hexachlorobenzene concentrations found in the eagles were: 0.087 µg/g wet weight, 0.010 µg/g, 0.007 µg/g, and 0.001 µg/g, respectively. There were no significant differences between sex or age classes.

22.

From 1987 to 1989, blood samples were taken from nestling bald eagles in Michigan, Minnesota, Ohio, Ontario, and Wisconsin (Bowerman et al., 1994a). Mean (range) DDE concentrations in the nestlings from the Great Lakes (N=42) and the interior (N=79) were, respectively: 61 (13-306) and 20 (2-193) mg/l. The mean concentrations of DDE were significantly higher in the nestlings from the Great Lakes. Total PCBs were also significantly higher in nestlings near the Great Lakes, 183 (33-520) µg/l, compared to the interior, 24 (5-200) µg/l.

23.

Blood plasma was collected from 309 nestling bald eagles from 10 sites in the Great Lakes between 1987 and 1992 (Bowerman et al., 2003). The geometric mean, range, and frequency of detectable concentrations of PCBs and DDE in plasma are presented in µg/kg and %. Chippewa Nat. Forest (N=43) PCBs 7 (<10-67) 23%, DDE 3 (<5-29) 19%. Superior Nat. Forest (N=15) PCBs 5 (<10-18) 7%, DDE 3 (<5-8) 13%. Voyageurs Nat. Park (N=21) PCBs 47 (<10-1,615) 91%, DDE 20 (<5-206) 13%. Lower peninsula (N=49) PCBs 31 (<10-200) 96%, DDE 10 (<5-193) 86%. Eastern upper peninsula (N=16) PCBs 32 (<10-146) 94%, DDE 12 (<5-24) 94%. Western upper peninsula (N=48) PCBs 25 (<10-177) 88%, DDE 10 (<5-245) 79%. Lake Superior (N=45) PCBs 127 (12-640) 100%, DDE 25 (<5-306) 89%. Lake Michigan (N=25) PCBs 154 (14-628) 100%, DDE 35 (<5-235) 100%. Lake Huron (N=12) PCBs 105 (5-928) 100%, DDE 25 (<5-78) 92%. Lake Erie (N=35) PCBs 199 (81-1,325) 100%, DDE 22 (<5-429) 100%.

24.

From 1989-94, 75 bald eagles were found dead from 6 areas in British Columbia (Elliott et al., 1996b). Geometric mean contaminant concentrations in the liver for each site ranged from 0.429-3.36 µg/g wet weight total PCBs, 0.42-4.93 µg/g DDE, and 0.046-0.321 µg/g trans-nonachlor. Individual concentrations ranged up to 15.2 µg/g for PCBs and 26.8 µg/g for DDE. Mean concentrations of oxychlordane, mirex, ß-HCH, dieldrin, and HCB were 0.052 µg/g. PCB congeners analyzed in 19 livers included 77 (248-2300 pg/g), 126 (349-9960 pg/g), 169 (56-2640 pg/g), 118 (37-4539 ng/g), and 105 (3-1289 ng/g). TEQs ranged from 53-2740 pg/g. Also analyzed were TCDD (4-392 pg/g), 1,2,3,7,8-PnCDD (9-1420 pg/g), 1,2,3,6,7,8-HxCDD (9-4360 pg/g), 2,3,7,8-TCDF (1-101 pg/g), and 2,3,4,7,8/1,3,4,8,9-PnCDF (trace-375 pg/g).

25.

Between 1989 and 1994, blood samples were collected from 89 bald eagle nestlings in 53 nesting territories in Wisconsin (15 nests within near Lake Superior and 38 inland nests) (Dykstra et al., 1998).  Blood samples collected from Lake Superior contained significantly greater concentrations of DDE (18.9 ng/g) and PCB (109.1 ng/g) than samples collected from interior nests (3.0 ng/g and 42.6 ng/g, respectively).  Contaminant concentrations showed no correlation with 5-year productivity rates in either region.

26.

Organochlorine contaminants were measured in blood collected between 1990 and 1996 from nestling bald eagles on Lake Erie (1990-1994, 1996; N=30), Lake Huron (1994; N=1), Lake Nipigon (1993; N=7), Lake Superior (1992, 1994; N=11), and Lake of the Woods (1992; N=2) (Donaldson et al., 1999).  Plasma concentrations of several contaminants did not differ between sites including DDE (means of lakes: 0.0471-0.1295 µg/g wet weight) , DDT (0.0001-0.0056 µg/g), and dieldrin (0.0031-0.0070 µg/g).  Plasma collected from Lake Erie contained significantly greater concentrations of total PCBs (0.1295 µg/g) than Lake Nipigon (0.0471 µg/g), though concentrations of total chlordane (0.0082 µg/g) and total mirex (0.0006 µg/g) were significantly lower than those at Lake Superior (0.0200 µg/g and 0.0012 µg/g, respectively).  No significant temporal trends were observed.

27.

Between 1992 and 1995, 6 blood samples were drawn from bald eagle nestlings in Wisconsin (Dykstra et al., 2001). In addition, 2 blood samples were collected in 1987 from Michigan (Bowerman, 1991: M.S. Thesis, Northern Michigan University). Green Bay nestling blood plasma (N=8) had geometric mean DDE concentrations of 53 mg/kg wet weight and total PCB concentrations of 207 mg/kg. Bald eagle nestling blood plasma samples had the following concentrations of DDE: 111, 235, 361, 4, 46, 95, 29, 13, and 53 mg/kg.  Total PCB concentrations were: 229, 319, 901, 83, 121, 393, 150, 87, and 207 mg/kg.

28.

A 12-year old female bald eagle was found on Santa Catalina Island, California, with suspected DDE poisoning (Garcelon et al., 1997). Concentrations of DDE were 53.0 µg/g wet weight in serum, 212.5 µg/g in brain, 838.3 µg/g in liver, and 317.5 µg/g in skeletal muscle. DDD was detected in serum only at 0.14 µg/g, and DDT was found in all four tissues at concentrations 0.11 µg/g. Total PCB concentrations were 26.0 µg/g in serum, 58.6 µg/g in brain, 294.0 µg/g in liver, and 3.9 µg/g in skeletal muscle

29.

In 1993-1994, blood was collected from 51 bald eagle chicks from 8 colonies on the coast of British Columbia (Elliott and Norstrom, 1998). Individual PCDD and PCDF concentrations were determined at the following ranges (pg/g wet weight): 0-0.80 2,3,7,8-TCDD, 0.01-1.6 1,2,3,7,8-PnCDD, ND-3.9 1,2,3,6,7,8-HxCDD, 0.01-25 1,2,3,4,6,7,8-HpCDD, 0.06-31 OCDD, 0.02-7.7 2,3,7,8-TCDF, 0.01-0.41 1,2,3,7,8-PnCDF, 0.01-0.55 2,3,4,7,8-PnCDF, 0.04-0.61 2,3,4,6,7,8-HxCDF, and 0.01-0.38 OCDF. 2,3,7,8-TCDF was the dominant congener detected in sites closest to a pulp mill. Other organochlorines were determined at the following ranges (ng/g wet weight): 1.9-69.6 total PCBs, 0.6-86 DDE, 0.1-6.4 trans-nonachlor, ND-1.8 oxychlordane, ND-0.8 dieldrin, ND-1.4 mirex, and 0.1-2.2 HCB. Non-ortho PCB congeners analyzed (pg/g wet weight) were 37 (0.31-35.2), 81 (0.01-6.02), 77 (0.89-52.3), 126 (ND-212), 169 (0.05-8.97), and 189 (0.03-1.49).

30.

During the summers of 1993 or 1994, a dead bald eagle nestling was collected from Kiska Island, in the Aleutian Islands, Alaska, USA (Anthony et al., 1999).  Concentration of DDE was 1.65 ppm dry weight, and concentration of PCBs was 1.05 ppm dry weight. 

31.

Blood was collected from 19 nestlings in 2 areas of Michigan in 1997 (Bowerman et al., 2002). Mean concentrations were recorded in µg/kg wet weight. Interior breeding area: Total PCBs 105.43, DDE 36.43, Hg 244.39. Great Lakes breeding area: Total PCBs 108.83, DDE 27.58, Hg 160.83.

32.

Between 1993 and 1998, liver and kidneys were collected from 26 bald eagle carcasses (Stout et al., 2002). Concentrations are in mg/kg, dry weight and were detected in at least 50% of samples.

Liver – HCB 88% detect, mean 0.025 µg/g, range (<0.06-0.300), total PCBs 100%, 1.46, (0.02-52.0), Alpha-chlordane 54%, 0.014 (<0.06-0.240), Beta-BHC 73%, 0.024 (<0.06-0.420), cis-nonachlor 65%, 0.020 (<0.06-0.320), Dieldrin 54%, 0.017 (<0.06-0.130), Heptachlor epoxide 54%, 0.014 (<0.06-0.130), Mirex 62%, 0.022 (<0.06-0.560), Oxychlordane 92%, 0.046 (<0.06-0.410), DDD 85%, 0.035 (<0.06-0.560), DDE 100%, 0.63 (0.01-10.0), trans-nonachlor 92% 0.094 (<0.06-1.260)

Kidney - HCB 50% detect, mean 0.041 µg/g, range (<0.06-0.105), total PCBs 100%, 4.83, (1.08-42.6), Alpha-chlordane 10%, NC, Beta-BHC 80%, 0.051 (<0.06-0.200), Cis-nonachlor 60%, 0.054 (<0.06-0.223), Dieldrin 40%, NC, Heptachlor epoxide 40%, NC, Mirex 40%, Oxychlordane 90%, 0.087 (<0.06-0.302), DDD 90%, 0.079 (<0.06-0.232), DDE 100%, 1.23 (0.24-8.09), trans-nonachlor 100%, 0.142 (0.040-0.851).

33.

In 2000, 8 eagles were found dead in the Upper Peninsula of Michigan (Kumar et al., 2002). Liver, muscle, fat, kidneys, and gall bladder were removed, analyzed and results recorded in wet weight. PCDD/DFs in livers were 23-4500 pg/g and blood plasma 2.3-49 pg/g. One eagle liver had 280,000 ng/g PCB.  Greatest DDE concentration was 17000 ng/g, and HCB 120 ng/g. Non-ortho coplanar PCBs accounted for 68-88% of total TEQs in tissues. PCDDs and PCDFs accounted for 17% of total TEQs.  Biliary excretion rates of PCDDs, PCDFs, and PCBs were 0.015-0.02% per day.

B.

Concentration in Eggs

1.

Addled bald eagle eggs collected from northwestern Ontario in 1967, 1968, 1971, 1972, 1976, 1977, 1980, and 1981 were analyzed to study the effects of the 1972 DDT ban (Grier, 1974, 1982). DDT declined from a high concentration of 2.62 µg/g dry weight in 1968 (no data 1967) to levels <0.36 in subsequent years and was not detected in nearly half the eggs sampled after 1971. DDE values ranged from 44 to 125 µg/g through 1972, peaking in 1971. From 1976 to 1981, DDE concentrations ranged from a low of 0.6 µg/g in 1977 to a maximum of 59.8 in 1976, with no clear pattern throughout the years. Concentrations of DDD reached highs of 5.17 µg/g in 1968, and 9.66 and 13.20 µg/g in 1971. DDD concentrations in all subsequent years studied (no data 1967) ranged from 0.61 to 3.18 µg/g. Dieldrin showed a general increase from 1967 to 1972, ranging from 1.21 to 8.21 µg/g. In 1976 one egg had a dieldrin concentration of 12.40 µg/g, with all other eggs from 1976, 1977, 1980, and 1981 from 1.31-5.42 µg/g. PCBs were measured in study years between 1971 and 1981 only. Concentrations were highest in an egg collected in 1971 at 977 µg/g; all others were between 47.5-218.2 µg/g.

2.

In 1968, bald eagle eggs were collected from nests in Maine, Wisconsin, and Florida (Krantz et al., 1970). Concentrations of DDE were greatest in Maine, with a mean of 21.76 µg/g wet weight, followed by Florida (10.72 µg/g) and Wisconsin (4.76 µg/g). DDD residue means were also greatest in Maine (0.82 µg/g), with similar levels in Florida (0.57 µg/g) and Wisconsin (0.32 µg/g). DDT was detected in 5 of 6 eggs in Maine, at a mean of 0.56 µg/g, 9 of 15 eggs in Wisconsin at levels <0.23 µg/g and 4 of 6 eggs in Florida at levels <0.67 µg/g. Dieldrin was detected in all eggs sampled with means of 1.41 µg/g in Maine, 0.21 µg/g in Florida, and 0.37 µg/g in Wisconsin. Heptachlor epoxide, detected in all but one egg, had a mean of 0.02 µg/g in all three states.

3.

Bald eagle liver, carcass, and egg samples were collected during 1968-76 in Maryland and Virginia (Stafford et al., 1978). Three eggs collected from the Potomac River, Virginia, in 1976, contained a median (range) kepone concentration of 0.15 (0.14-0.19) µg/g (calculated as µg/mol on the basis of total egg volume and converted to µg/g assuming a specific gravity of 1.0).

4.

In 1969 and 1970, bald eagle eggs were collected from Alaska, Maine, Michigan, Minnesota, and Florida (Wiemeyer et al., 1972). The mean DDE concentration in Kodiak, Alaska was 1.92 µg/g and in Admiralty Island, Alaska was 2.91 µg/g, and mean DDE concentrations were higher in Maine (14.95 µg/g), Michigan (39.46 µg/g), Minnesota (9.57 µg/g), and Florida (18.37 µg/g). DDD was detected at much lower concentrations at all locations, with the highest mean concentration of 1.81 µg/g in Lee County, Florida. Concentrations of DDT and heptachlor epoxide were <1 µg/g. The highest mean concentration of dieldrin was 1.11 µg/g in Florida. Mean PCB concentrations ranged from a low of 1.1 µg/g in Alaska to 27.7 µg/g from a single egg collected from Michigan.

5.

From 1969 through 1979, eggs were collected from various breeding areas in 14 states and tested for the presence of several organochlorines (Wiemeyer et al., 1984).

DDE was detected in eggs from every breeding area with a low of <1.0 µg/g wet weight in Alaska sites (1975) to a high of 42 µg/g in Maine (1974). Other states with high concentrations were Wisconsin, Michigan, Ohio, New York, Delaware, and Maryland, which had all breeding areas with eggs measuring over 20 µg/g.

DDD was detected in eggs from all states studied except Alaska. The greatest concentrations were detected in Delaware (1977-78) with values from 2.7-4.1 µg/g and Ohio (1976), where concentrations were >2.0 µg/g. Maryland (1977-78) and Virginia (1976-77, 1979) also had several breeding areas with concentrations >1.0 µg/g.

DDT was detected sporadically among the samples. Moosehead Lake, Maine (1976) had a mean concentration of 1.2 µg/g wet weight, and all other concentrations were <0.13 µg/g.

Dieldrin was detected in eggs from breeding areas in all states but Oregon. States with concentration >1.0 µg/g were Minnesota (up to 1.6 µg/g wet weight), Wisconsin (2.4 µg/g), Michigan (1.0 µg/g), Ohio (1.8 and 1.6 µg/g), Maine (1.2 µg/g), Delaware (1.6 µg/g), Maryland (2.6 µg/g), and Virginia (2.8 µg/g).

Heptachlor epoxide was detected in all states except Alaska, California, and Arizona. In all states, the majority of concentrations were <0.10 µg/g wet weight. Minnesota, Wisconsin, Ohio, Maine, Maryland, and Virginia had high values ranging from 0.20 to 0.36 µg/g.

Oxychlordane was generally found in concentrations 0.10 µg/g wet weight. Exceptions included Virginia, which had means ranging from 0.17-0.30 µg/g over three years, and Florida, Maryland, Maine and Delaware, which had means between 0.10 and 0.20 µg/g. The highest concentration was detected in Wisconsin in 1978 at 0.56 µg/g.

cis-Chlordane was detected in most of the eggs analyzed. The greatest concentrations were found in Maryland (up to 1.4 µg/g) and Virginia (up to 3.6 µg/g) in 1977. Ohio had the next highest concentrations of 0.59 and 0.51 µg/g in 1976. All other concentrations were <0.32 µg/g, with the majority <0.10 µg/g.

trans-Nonachlor was detected in eggs from most breeding areas, with Maryland and Virginia again containing the highest concentrations (2.5 µg/g in 1978 and 2.7 µg/g in 1979, respectively). Eggs collected from Ohio and Wisconsin, both in 1976, also contained levels >1.0 µg/g. Delaware contained a high value of 0.94 µg/g (1977) and Florida reached a maximum of 0.72 µg/g (1976). Eggs from all other states contained concentrations <0.43 µg/g.

cis-Nonachlor was detected in eggs from most breeding areas. Maryland and Virginia eggs both had high values in 1977 of 0.74 and 1.5 µg/g, respectively. Wisconsin had a single egg (from Wolf River in 1976) at a concentration of 0.98 µg/g, with most other values <0.10. Values for all other states were <0.27 µg/g, with the majority <0.10 µg/g.

Toxaphene was most frequently found in eggs from Wisconsin (concentrations were detected up to 0.84 µg/g). It was also detected in single eggs from Arizona, Minnesota, Michigan, New York, Louisiana, and several eggs from Maine.

Mirex was detected in approximately 50% of the eggs, but in only one egg from a western state. Levels were generally <0.10 µg/g, though concentrations in Florida were detected up to 2.0 µg/g.

PCBs were detected in eggs from every breeding area. Levels ranged from 0.20 µg/g wet weight (Kittridge Ranch, Oregon, 1981) to 37 µg/g (Hockamock Point, Maine, 1980). Maine contained the highest mean concentrations of 26 µg/g in 1980 and 24 µg/g for a single colony tested in 1984. Virginia had a mean of 23 µg/g in 1982 and Remington Farms, Maryland contained PCB concentrations of 36 µg/g in 1980.

Kepone was measured only in states from the Chesapeake Bay area. Holly Forks, Virginia had concentrations of 5.1 and 5.4 µg/g wet weight in 1977, while all other eggs measured contained <0.33 µg/g.

6.

Bald eagle eggs were collected from various locations in Canada (Gilbertson and Reynolds, 1974). The following geometric means, expressed as dry weights, were determined for DDE and PCB respectively for each region: Saskatchewan (N=9), 22.4 and 14.2; and Ontario (N=18), 164 and 140.

7.

Organochlorine contaminants were measured in unhatched bald eagle eggs collected between 1974-1980 (N=6) and 1989-1994 (N=6) from nests on Lake Erie and between 1993-1996 from nests on Lake of the Woods (N=7) (Donaldson et al., 1999).  Concentrations of DDE and PCBs were significantly greater at Lake Erie during 1974-1980 compared to the later collection.  Contaminant concentrations for all three groups, respectively, were 84, 26, and 3.27 µg/g wet weight total PCBs, 24.5, 10.8, and 3.3 µg/g DDE, 0.64, 0.16, and 0.04 µg/g total chlordane, 1.28, 0.49, and 0.12 µg/g dieldrin, and 0.31, 0.45, and 0.04 µg/g total mirex. 

8.

From 1977 to 1985 eggs were collected from various locations throughout Arizona (Grubb et al., 1990). DDE was detected at a mean concentration of 3.3 µg/g wet weight. DDD, dieldrin, cis-chlordane, trans-nonachlor and cis-nonachlor and toxaphene were detected at <1 µg/g. PCBs were detected at a concentration of 1.1 µg/g.

9.

From 1980 through 1984, eggs were collected from approximately 75 different breeding areas in 15 states (Wiemeyer et al., 1993). Data was combined with that of earlier studies and analyzed with regard to trends in time and trends between populations.

DDE was detected in eggs from every breeding area with concentrations ranging from <1.0 µg/g wet weight at Salisbury Point, Alabama (1983) to 20.0 µg/g at Photographer’s Nest, Oregon (1981). Other states with high concentrations were Maine, which had geometric means over 9.0 µg/g in 1980 and 1982, New Jersey (1982), in which a single egg contained 13.0 µg/g, and Delaware (1982), which had a concentration of 16.0 µg/g at Bombay Hook. Means from other states ranged from 1.2 to 6.6 µg/g.

DDD was detected in eggs from over 90% of breeding areas. The greatest concentrations were detected at Michigan Island, Wisconsin (1.3 µg/g wet weight, 1980), Remington Farms, Maryland (1.1 µg/g, 1980), Bull Bluff, Virginia (0.96 µg/g, 1982) and New Jersey (0.87 µg/g, 1982). Eggs from Ohio contained concentrations of 0.46 to 0.72 µg/g in 1981 and 1983. An eggs from Maine reached a concentration of 0.52 in 1984. States with mean levels between 0.27 and 0.50 µg/g were Oregon (1982), Delaware (1983), Maryland (1980-1984), Virginia (1981-1984), and Florida (1981).

Dieldrin was detected in eggs from over 90% of breeding areas. The greatest concentrations were detected at Keshena, Wisconsin (1.8 µg/g wet weight, 1981), Remington Farms, Maryland (1.2 µg/g, 1980), and Michigan Island, Wisconsin (1.0 µg/g, 1980; 1.1 µg/g, 1982). Concentrations in Ohio ranged from 0.37 to 0.83 µg/g in 1981 and 1983. Other sites with concentrations over 0.50 µg/g were Balsam and Stone Lakes and Ferryville, Wisconsin (0.73, 0.55, and 0.56 µg/g, respectively), Cocktown Creek and Aberdeen Proving Grounds, Maryland (0.74 and 0.67 µg/g), Bull Bluff, Virginia (0.61 µg/g), and North Fort Myers, Florida (0.92 µg/g).

Heptachlor epoxide was found in about 50% of breeding areas and reached concentrations of 0.37 µg/g in North Fort Myer, Florida (1983) and 0.35 µg/g in Flambeau River, Wisconsin (1982). Concentrations at all other sites were <0.24 µg/g.

Oxychlordane was found in eggs from over 70% of the breeding areas. The vast majority of eggs with detectable oxychlordane (>90%) contained <0.21 µg/g wet weight. North Fort Meyers, Florida contained the greatest concentration (0.51 µg/g, 1983), followed by Barlett Island, Maine (0.37 µg/g, 1982), Flambeau River, Wisconsin (0.36 µg/g, 1982), and Michigan Island, Wisconsin (0.29 µg/g, 1980).

cis-Chlordane was detected in over 70% of the breeding areas. The greatest concentrations were found in Aberdeen Proving Grounds, Maryland (0.86 µg/g, 1982), Remington Farms, Maryland (0.79 µg/g wet weight, 1980), Bull Bluff, Virginia (0.75 µg/g, 1982), Cocktown Creek, Maryland and Keshena , Wisconsin (0.64 µg/g, 1981), and North Fort Meyers, Florida (0.51 µg/g, 1983). Concentrations at all other areas were <0.45 µg/g.

trans-Nonachlor was detected in eggs from over 90% of the breeding areas. The greatest concentrations were found at Remington Farms, Maryland (1.7 µg/g wet weight, 1980), North Fort Meyers, Florida (1.4 µg/g, 1983), Cocktown Creek and Aberdeen Proving Grounds, Maryland (1.2 µg/g, 1981 and 82), and Michigan Island, Wisconsin (0.95 µg/g, 1980).

cis-Nonachlor was detected in eggs from over 70% of the breeding areas. The greatest concentrations were found at Remington Farms, Maryland (0.43 µg/g wet weight, 1980), North Fort Meyers, Florida (0.41 µg/g, 1983), and Flambeau River, Wisconsin (0.39 µg/g, 1982). Concentrations at all other areas were <0.20 µg/g.

Mirex was detected in approximately 25% of eggs. The only with eggs containing detectable mirex were Ohio and Maine (<0.20 µg/g wet weight), Maryland (<0.65 µg/g), Virginia (<0.21 µg/g) and Florida (0.04 and 0.59 µg/g).

PCBs were detected in eggs from every breeding area. Levels ranged from 0.20 µg/g wet weight (Kittridge Ranch, Oregon, 1981) to 37 µg/g (Hockamock Point, Maine, 1980). Maine contained the highest mean concentrations with 26 µg/g in 1980 and 24 µg/g for a single colony tested in 1984. Virginia had a mean of 23 µg/g in 1982. Remington Farms, Maryland contained PCB levels of 36 µg/g in 1980.

10.

In 1980 and 1982, addled eggs were collected from Madeline and Michigan Islands, along the southwest shore of Lake Superior, Wisconsin (unpublished data from Wiemeyer in Kozie, 1991). DDE concentrations were 13 and 14 µg/g, dieldrin was 1.0 and 1.1 µg/g, and PCBs were 6.8 and 12 µg/g.

11.

Eggs were collected from the upper Klamath Lake, the Outer Klamath Basin, and Cascade Lake located in southcentral Oregon (Frenzel, 1985). Concentrations of DDE in eggs from all locations ranged from 1.5-20.0 µg/g wet weight. Concentrations of other organochlorines were <1 µg/g. PCB concentrations ranged from 0.18 to 12 µg/g.

12.

Concentrations of DDE in 4 unhatched eagle eggs collected in 1985 from the Chesapeake Bay area were of 2.4, 7.1, 8.5, and 9.0 µg/g (unpublished data from Goodbred in Ohlendorf, 1988).

13.

Eggs were collected from the Columbia River estuary from 1985 to 1987 (Anthony et al., 1993). DDE was detected at a mean concentration of 9.7 µg/g wet weight, DDD at 1.4 µg/g and PCBs at 12.7 µg/g. HCB and mirex concentrations were at 0.3 and 0.2 µg/g, respectively. The mean concentration of TCDD in 5 eggs was 31.98 ng/kg.

14.

From 1986 to 1990, addled bald eagle eggs were collected in Michigan, Minnesota, Ohio, Ontario, and Wisconsin (Bowerman et al., 1994a). Mean dieldrin concentrations were <1.1 mg/g wet weight in all areas. Mean (range) concentrations for Michigan Lower Peninsula (N=4), Michigan Upper Peninsula (N=9), interior Ohio (N=3), Lake Superior (N=3), Lake Erie (N=7), Lake Michigan (N=2), and Lake Huron (N=3) were, respectively: 2.2 (1.0-5.7) mg/g DDE and 6.2 (1.9-14) mg/g total PCBs; 1.7 (0.5-16) mg/g DDE and 5.0 (1.8-29) mg/g total PCBs; 1.8 (1.3-3.1) mg/g DDE and 9.0 (5.7-20) mg/g total PCBs; 3.2 (1.5-9.5) mg/g DDE and 8.5 (3.4-14) mg/g total PCBs; 2.8 (1.9-10) mg/g DDE and 20 (8.6-44) mg/g total PCBs; 17 (10-30) mg/g DDE and 38 (27-55) mg/g total PCBs; and 16 (8.5-41) mg/g DDE and 73 (50-110) mg/g total PCBs.

15.

From 1986 to 1991, unhatched and broken eggs were collected from Arizona, northern California, and Santa Catalina Island (Jenkins et al., 1994). DDE concentrations were measured on the following unhatched eggs (in mg/g wet weight): 

In Arizona: 2.3 from Cedar Basin in 1988, 8.9 from Chino in 1986, 8.0 from McDowell in 1988, 7.7 from Cliff in 1989, 3.4 from Horseshoe in 1989, 5.3 from Alamo in 1989, and 4.7 (est.) from Horse Mesa in 1986. 

On Santa Catalina Island: 25 (est.) from Twin Rocks in 1987, 67 (est.) from Seal Rocks in 1988, and 44 (est.) from Pinnacle Rock in 1991. 

In northern California: 2.5 from Dusty in 1986, 2.5 from Dusty in 1988, 4.7 from South Shore in 1985, 4.1 from North Shore in 1986, 1.3 from Pit 3 in 1990, 0.50 from Pit 6 in 1989, 8 from O’Brien in 1986, 9.5 (mean; N=2) from Packer’s Bay in 1984, 1.3 from Packer’s Bay in 1991, 10 from Hirz Bay in 1984, 5.6 from Lake Pillsbury in 1984, 2.5 from Mountain Meadows West in 1986, 8.5 from Cool Springs in 1986, 22 from Rocky Point in 1986, and 2.6 from Mud Creek Rim in 1984. 

The following broken or crushed eggs had DDE concentrations (in mg/g lipid): 210 from Twin Rocks, Santa Catalina Island, in 1989, 1,100 from Seal Rocks, Santa Catalina Island, in 1990, 120 from South Shore, Northern California, in 1983, and 150 from North Shore, Northern California, in 1984.

16.

Between 1986 and 1996, 15 addled bald eagle eggs were collected from Michigan and Wisconsin (Dykstra et al., 2001). Green Bay bald eagle eggs (N=9) had higher geometric mean concentrations of DDE and total PCBs (8.3 and 31.3 mg/g wet weight, respectively) than did inland Wisconsin eggs (N=20) (1.09 and 2.4 mg/g, respectively).

17.

Eggs collected from the South Shore Nesting Territory located in northcentral California contained DDE concentrations ranging from 4.2 to 8.4 µg/g wet weight (Jenkins, 1995).

18.

From 1990-92, 32 bald eagle eggs were collected from the south coast of British Columbia, including locations near bleached-kraft pulp mills, the highly industrialized Fraser River estuary, and reference sites on the Pacific coast of Canada (Elliot et al., 1996c). Geometric mean contaminant concentrations for eight sites ranged from 1.91-5.08 µg/g wet weight total PCBs, 2.17-5.14 µg/g DDE, and 0.142-0.32 µg/g trans-nonachlor. Mean concentrations of cis-nonachlor, oxychlordane, mirex, photomirex, ß-HCH, dieldrin, DDT, and HCB were 0.061 µg/g. PCB congeners analyzed from ten sites included non-ortho-substituted 37 (5-52 pg/g), 81 (24-107 pg/g), 77 (248-2300 pg/g), 126 (349-9960 pg/g), 169 (56-2640 pg/g), and 189 (1-97 pg/g). Also analyzed were TCDD (2-110 pg/g), 1,2,3,7,8-PnCDD (5-211 pg/g), 1,2,3,6,7,8-HxCDD (3-374 pg/g), 1,2,3,7,8,9-HxCDD (ND-15 pg/g), 2,3,7,8-TCDF (5-168 pg/g), and 2,3,4,7,8-PnCDF (ND-50 pg/g). Mean TEQs were 210 pg/g, about twofold greater than the lowest-observed-effect level. Pulp mill sites in the Strait of Georgia had significantly higher TCDD concentrations than the reference area in Johnstone Strait, and a significantly different PCB congener pattern than sites in the Johnstone Strait and the lower Fraser Valley.

19.

Contaminants were measured in eggs of bald eagles exhibiting low nest success between 1993-1997 on the Delaware Bay in New Jersey (Clark et al., 1998).  One egg was collected for each year of reproductive failure (1993, 1994, 1995, 1997) at Raccoon Creek and one egg was collected from Stow Creek following reproductive failure in 1997.  Concentrations of DDE were elevated at both Raccoon Creek (12-18 µg/g fresh weight) and Stow Creek (6.3 µg/g).  DDD concentrations ranged from 2.1-2.8 µg/g at Raccoon Creek and 0.62 µg/g at Stow Creek, and DDT was < 0.03 µg/g in all samples.  Total PCB concentrations were 24-54 µg/g at Raccoon Creek and 20 µg/g at Stow Creek.  TCDD-EQs ranged from ND-809 pg/g at Raccoon Lake and 331 pg/g at Stow Creek, of which PCB 126 and combined non-ortho substituted PCBs accounted for 52-60% and 72-77%, respectively.  Concentrations of PCB congeners at both sites ranged from  ND-2.1 µg/g 77, ND-0.76 ng/g 81, ND-4.3 ng/g 126, ND-0.86 ng/g 169, ND-1000 ng/g 105, ND-70 ng/g 114, ND-2300 ng/g 118, ND-600 ng/g 123, ND-500 ng/g 156, ND-230 ng/g 157, ND-190 ng/g 167 and ND-46 ng/g 189.

20.

During the summers of 1993 and 1994, unhatched bald eagle eggs (N=25) were collected from Adak, Tanga, Amchitka, and Kiska Islands, in the Aleutian Islands, Alaska (Anthony et al., 1999). The following contaminants were detected in most eggs(most values estimated from graph): PCB-1260 (geometric means ranged from 0.70 – 2.15 ug/g wet weight), p,p-DDE (0.55 – 2.55 ug/g), ß-BHC (0.02 – 0.09 ug/g), HCB (0.02 – 0.252 ug/g), oxychlordane (0.02 - 0.08 ug/g), trans-nonachlor (0.10 – 0.27 ug/g), dieldrin (0.01 – 0.135 ug/g), and mirex (0.021 – 0.047 ug/g);.  Heptachlor epoxide (LOD – 0.03 ug/g) and p,p-DDT (concentration not given) were detected in some eggs.  PCB-1242,-1248, and 1254, toxaphene, α-BHC and δ-BHC, α-chlordane and δ-chlordane, endrin, o,p-DDT, o,p-DDE, o,p-DDD, and p,p-DDD were detected in <3 eggs (concentrations not given).  Geometric means of PCB-1260 for Adak, Kiska, Amchitka, and Tanga Islands, respectively were 2.1, 2.0, 1.7, and 0.70 µg/g wet weight, with concentrations reaching 9.9 µg/g on Adak Island.  Eggs from Kiska Island contained significantly higher mean concentrations of p,p-DDE (approx. 2.50 µg/g), mirex (<0.05 µg/g), oxychlordane (<0.10 µg/g), and trans-nonachlor (<0.30 µg/g) than eggs from the other 3 islands.

21

Addled bald eagle eggs were collected from five of the Great Lakes from 1986 to 1995 (Weseloh et al., 2002). Contaminant levels in eggs are presented in mg/g wet weight for means and SD: Erie (N=10) DDE 3.60±2.37, dieldrin 0.44±0.15, Total PCBs 29.02±13.58. Superior (N=1) DDE 9.54, dieldrin 0.51, Total PCBs 12.91. Michigan (N=7) DDE 11.66±8.79, dieldrin 0.69±0.64, Total PCBs 31.40±13.19. Huron (N=4) DDE 7.62±3.03, dieldrin 0.34±0.19, Total PCBs 42.32±22.08.

II.

Cholinesterase-Inhibiting Pesticides

1.

Cholinesterase activity was measured in the blood collected from 15 migrating bald eagles between 1985 and 1993 in west-central Montana (Harmata and Restani, 1995). Mean cholinesterase activity in the plasma collected from the eagles was 691±32 µmoles/min/L, acetylcholinesterase was 171±15 µmoles/min/L, and butyrylcholinesterase was 520±28 µmoles/min/L. No significant differences were found between adult and immature or female and male cholinesterase activity in plasma.

2.

In 1990, six bald eagles in good body condition were found in British Columbia, Canada, in agricultural areas adjacent to a golf course in Richmond or on farmlands in Ladner (Elliott et al., 1996a). Crop content analysis in two of these birds revealed 200 µg/g carbofuran in one eagle and no detectable pesticides in the other.

3.

In December 1992, three bald eagles were found dead in a field in north-central Kansas where furadan had been illegally used to poison coyotes (Allen et al., 1996). The crop from a mature female eagle included 196 g of freshly ingested meat from sheep containing 1.1 µg/g carbofuran. Crops from two immatures, one male and one female, contained 166 g meat containing 5.4 µg/g carbofuran and 70 g of meat containing 4.8 µg/g carbofuran.

III.

Trace Elements, Metals, and Metalloids

A.

Concentrations in Adults and Nestlings

1.

Mercury concentrations in the carcass of bald eagles collected from 13 states throughout the United States were higher in 1970 (2.5 µg/g wet weight) than 1969 (1.5 µg/g) (Belisle et al., 1972). .

2.

In 1975, an immature female bald eagle was found near Lake Sangchris, Illinois (Collier et al., 1976). Hepatic metal concentrations were 0.21 µg/g total Hg, 1.05 µg/g Pb, and 2.80 µg/g Cu.

3.

Lead poisoning was suspected in an immature bald eagle found intoxicated in western Maryland (Jacobson et al., 1977). A total of 75 Pb shot were found in the gizzard. Concentrations of Pb in the liver and kidney were 22.9 and 11.3 µg/g, respectively.

4.

From 1975 to 1977, 168 eagle carcasses were collected from 29 states throughout the United States (Kaiser et al., 1980). Nine of the birds collected contained elevated concentrations of Pb in the liver, ranging from 22.9 to 38.1 µg/g.

5.

The mean Pb concentration in the liver of six eagles collected from southern and central Idaho between 1977 and 1984 was 25.70 µg/g wet weight (Craig et al., 1990).

6.

From 1979-1981, blood samples were collected from eagles in Oregon, northern California, Montana, and Washington (Wiemeyer et al., 1989). The geometric mean Pb concentration was highest in wintering birds from Oregon and northern California at 0.129 µg/g wet weight. Mercury in the blood ranged from 0.23 µg/g in resident birds from Washington State to 3.0 µg/g in subadults from Oregon

7.

Lead and Hg concentrations in the blood of nestlings, subadults, and adults were measured in the Columbia River estuary from 1984-1986 (Anthony et al., 1993). Mean Pb levels were lowest in the subadults (0.17 µg/g wet weight) and highest in the adults (0.43 µg/g). Mean Hg levels increased with age with the lowest levels in the nestling (0.47 µg/g) and the highest in adults (3.07 µg/g).

8.

Two immature and six nestling eagles were collected from 1984-1986 from colonies in Lake Superior and inland locations (Kozie and Anderson, 1991). Mercury concentrations were greatest in eagles from the Lake Superior colonies, reaching a maximum of 4.4 µg/g wet weight in the kidney.

9.

Contaminant concentrations were measured in blood and tissues of bald eagles wintering in the Klamath basin, Oregon and California, between 1979 and 1982 (Frenzel and Anthony, 1989). Geometric mean concentrations in adults and subadults in blood were 2.29 and 2.17 µg/g wet weight Hg, and 0.04 and 0.13 µg/g Pb. In the liver, Pb was detected in 9 of 10 adults and subadults (0.32-27.0 µg/g) and Hg was detected in 7 of 10 livers (0.76-8.0 µg/g).

10.

From 1979 to 1983 bald eagles were collected from southcentral Oregon during the breeding and winter seasons (Frenzel, 1985). Mercury, Pb, and Cd concentrations in the blood of nestlings were measured during the breeding season. The geometric mean concentration for Hg was 0.220 µg/g wet weight. Lead concentrations ranged from ND-0.22 µg/g and Cd from ND-0.11 µg/g. Mercury in blood collected from adults ranged from 1.10-4.8 µg/g and in subadults from 2.80-3.20 µg/g. Lead was only detected in one adult female at a concentration of 0.25 µg/g and Cd was detected in just two adults at 0.10 and 0.11 µg/g. Mercury in the blood of wintering eagles occurred at a geometric mean concentration of 2.285 µg/g in adults and 2.166 µg/g in subadults, and Pb at 0.038 µg/g in adults and 0.129 µg/g in subadults.

11.

In 1981 and 1983, two bald eagles were found dying at Lac Qui Parle Wildlife Refuge in Minnesota (Bengtson, 1984). The eagle found in 1981 had a Pb concentration in the blood of 2.4 µg/g. The eagle found in 1983 contained 1.36 µg/g in the blood and 12.46 µg/g in the liver.

12.

Feathers were collected from eagles nesting in over 100 breeding areas in the Great Lakes between 1985 and 1989 (Bowerman et al., 1994b). In adult feathers, Hg levels ranged from 19 to 21 µg/g and Se from 1.6 to 1.9 µg/g. In nestling feathers, Hg had a mean concentration of 9.0 µg/g and Se had a mean of 1.9 µg/g.

13.

Thirty-seven blood samples were collected from eagles in west-central Montana between 1985 and 1993 (Harmata and Restani, 1995).  Mean (maximum) Pb, Hg, and Se concentrations were, respectively: 0.32 (1.10) µg/g wet weight, 0.54 (1.70) µg/g, and 0.55 (2.80) µg/g.  Mean Pb concentrations declined over the study period from 0.53 µg/g in 1987 to 0.35 µg/g in 1992.

14.

From 1987-1993, Hg concentrations were determined in liver, blood, and feathers from carcasses and nests of bald eagles from Florida (Wood et al., 1996). From carcass specimens, mean (range) Hg concentrations in the liver were 3.21 (0.63-12.20) µg/g in adults, 2.58 (0.35-5.42) µg/g in subadults, and 0.42 (0.14-1.01) µg/g in nestlings. Also from carcasses, mean Hg concentrations in feathers and blood were determined for mixed age groups at 7.40 (2.38-13.70) µg/g and 0.63 (0.07-1.35) µg/g, respectively. Mercury values were determined in samples drawn from nests in both nestlings [0.17 (0.02-0.61) µg/g in blood and 4.05 (0.76-14.30) µg/g in contour feathers] and adults [11.51 (2.01-34.70) µg/g in contour feathers, and 9.09 (0.10-34.70) µg/g in all feathers combined]. Mercury concentrations in nestlings and adults from the same nest were correlated.

15.

From 1989 through 1990, 65 bald eagle carcasses were collected throughout British Columbia (Elliott et al., 1992). Nine of the 65 showed signs of Pb poisoning. Mean Pb concentrations were 34 µg/g dry weight in the kidneys and 7.3 µg/g in the bone. For 15 of the 65 which exhibited Pb concentrations at ‘subclinical’ levels, mean Pb concentrations (only from detectable results) were 2.8 µg/g in the kidney and 1.9 µg/g in the bone.

16.

Between 1990 and 1996, golden and bald eagles found dead were collected from Alberta, Saskatchewan, and Manitoba, Canada (Wayland et al., 1999).  No significant differences were found for Pb concentrations between golden and bald eagles, therefore data were combined.  In liver (N=199), Pb concentrations ranged from ND-243 µg/g dry weight.  Background exposure to Pb (<6 µg/g) was indicated in 100 of the livers, and elevated concentrations were found in 19 livers, 14 of which were consistent with Pb poisoning.  Concentrations of Pb in kidney (N=109) ranged from ND-109 µg/g, with 90 kidneys containing <6 µg/g. In bone (N=49), Pb values ranged from ND-18 µg/g, with 31 samples containing <9 µg/g.  Hepatic and renal concentrations of lead were highly correlated.

17.

Between 1990 and 1996, 96 bald eagles found dead were collected from Alberta, Saskatchewan, and Manitoba, Canada (Wayland and Bollinger 1999). Lead concentrations in 14% of the bald eagles were above background concentrations.  One immature and 1 adult/subadult had elevated Pb concentrations (> 6 µg/g in liver, 8 µg/g in kidney), and 1 immature and 10 adult/subadult had toxic Pb concentrations (> 20 µg/g in liver or kidney).  Bald eagles with elevated Pb concentrations occurred more frequently in areas of high waterfowl hunting intensity (> 1,000 hunter days per year).

18.