Reduction of organochlorine residues in Goshawk eggs (Accipiter gentilis) from Northern Germany (1971-2002) and increasing eggshell index.
We investigated unhatched eggs (n = 57) of Goshawks (Accipiter gentilis) from the period 1988--2002 and compared them with eggs (n = 134) from 1971--1978. Mean concentrations of PCBs, sigmaDDT and HCB in the earlier period were (mg kg(-1) lipid weight) 50.1, 126.6, and 117.7, while the values from the later period were statistically significantly lower: 27.7, 4.1, 0.1, respectively. Nevertheless, the concentration of PCB is relatively constant during the last 8-10 years. The variability of residues was lower within clutches than among clutches. No age-dependent accumulation in eggs could be demonstrated. A statistically significant lower shell index was measurable for the period 1971--1978, while this index during 2001--2002 was relatively high as it was during the late 18th century. We are suggesting a threshold value for effect concentrations on shell index. Residues of the DDT-group had an influence on the number of fledged young per nest site.
Scharenberg
Wolfgang
W
University of Kiel, Germany. wolfgang.scharenberg@arcor.de
Looft
Volkher
V
D000818:Animals; D004781:Environmental Exposure / Q000032:analysis* / Q000706:statistics & numerical data*; D004784:Environmental Monitoring / Q000379:methods; D005260:Female; D005858:Germany; D046428:Hawks / Q000196:embryology*; D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D010063:Ovum / Q000737:chemistry*
D006843:Hydrocarbons, Chlorinated