Eggshell thinning, chlorinated hydrocarbons, and mercury in inland aquatic bird eggs, 1969 and 1970
Pesticides Monitoring Journal
1504_Faber.pdf
By: R.A. Faber and J.J. Hickey
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Abstract
In the Upper Great Lakes States, 9 out of 13 species of fish-eating birds were found in 1969-70 to have sustained statistically significant decreases in eggshell thickness since 1946. Maximum changes in a thickness index occurred in great blue herons (-25%), red-breasted mergansers (-23%), common mergansers (-15%). and double-crested cormorants (-15%). Heron eggs taken in Louisiana generally displayed a smaller post-'46 change than herons in the Middle West. On a lipid basis, mean PCB- and DDE- residue levels exceeded 100 ppm in 7 out of 13 species in the Great Lakes States, and in 2 of 7 species in Louisiana, the average DDE: PCB ratios in the two regions being 1.25:1 and 3.9:1, respectively. Individual dieldrin values tended 10 be higher in Louisiana (31.6 and 13.95 ppm in heron species from two different locations), although values reached 10.1 and 9.4 ppm in great blue and black-crowned night herons in Wisconsin. BHC averaged 3.01 and 0.39 ppm in the Lake States and Louisiana, respectively. Of eggs examined for mercury. 29% had levels greater than 0.5 ppm, and 9% greater than 1.0 ppm on a wet-weight basis. Mercury levels in a small sample of eggs from Louisiana were consistently low. The differences in mercury levels between the two regions thus were similar to those found for the chlorinated hydrocarbons. While DDE was a prominent factor for most groups, especially herons, in relation to the eggshell thinning observed, dieldrin was also important to two groups even though DDE was present in much higher amounts. PCB's were also important to mergansers, while mercury was positively correlated with thickness index in grebes and negatively correlated in mergansers.
| Publication type | Article |
|---|---|
| Publication Subtype | Journal Article |
| Title | Eggshell thinning, chlorinated hydrocarbons, and mercury in inland aquatic bird eggs, 1969 and 1970 |
| Series title | Pesticides Monitoring Journal |
| Volume | 7 |
| Issue | 1 |
| Year Published | 1973 |
| Language | English |
| Contributing office(s) | Patuxent Wildlife Research Center |
| Description | 27-36 |
| Larger Work Type | Article |
| Larger Work Subtype | Journal Article |
| Larger Work Title | Pesticides Monitoring Journal |
| First page | 27 |
| Last page | 36 |
| Google Analytic Metrics | Metrics page |