Residue levels of organochlorine and mercury compounds in unhatched eggs and the relationships to breeding success in white‐tailed sea eagles Haliaeetus albicilla in Sweden

• Published in: Ecography
• Main Authors: Helander, Björn, Olsson, Mats, Reutergårdh, Lars
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1982
• Subjects: Haliaeetus albicilla; Lapland
• Online Access: http://dx.doi.org/10.1111/j.1600-0587.1982.tb01049.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1600-0587.1982.tb01049.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1600-0587.1982.tb01049.x

Eighty‐five unhatched eggs from 68 white‐tailed sea eagle clutches were collected during 1965–1978 along the Baltic coast and in Lapland. The eggs were analysed individually for residue levels of DDT and its metabolites, PCB and mercury. Pooled samples were analysed for levels of dieldrin and hexachlorobenzene (HCB). The variations in residue levels within and between clutches were studied before the material was grouped for investigations of relationships between reproduction and contamination. Levels of DDE, PCB and mercury were significantly higher in the Baltic as compared to the Lapland material. In the Baltic, the reproductive success on a clutch basis and on a nest basis was significantly and negatively correlated to the egg residue levels of DDE and PCB; no correlation was found with mercury. Critical ranges were estimated to 500–600 mg kg 1 of DDE and/or 800–900 mg kg −1 of PCB (lipid basis). The levels of dieldrin and HCB in the pooled samples were not considered important to reproduction. In a comparative study including six sea eagle and six bald eagle populations, productivity showed the strongest correlation with DDE.