Reproduction and organochlorine contaminants in terns at San Diego Bay

Colonial Waterbirds
By: , and 



In 1981, we studied Caspian Terns (Sterna caspia) and Elegant Terns (S. elegans) nesting at the south end of San Diego Bay, California. Randomly collected Caspian Tern eggs contained signficantly (P < 0.05) higher mean concentrations of DDE (9.30 ppm) than did Elegant Tern eggs (3.79 ppm). DDE may have had an adverse effect on Caspian Tern reproduction but the relationship between hatching success and DDE concentration was not clear. We found an unusually high incidence of chicks (4.6%) that died in hatching. Caspian Tern eggs that broke during incubation or contained chicks that died while hatching had shells that were significantly (P < 0.05) thinner than eggs collected before 1947, and DDE was associated with reductions in shell thickness index (i.e., lowered eggshell density). Fish brought to Caspian Tern chicks contained up to 3.0 ppm DDE and 1.1 ppm PCBs. Organochlorine concentration brains of terns found dead were not high enough to suggest such poisoning as a cause of death.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Reproduction and organochlorine contaminants in terns at San Diego Bay
Series title Colonial Waterbirds
Volume 8
Issue 1
Year Published 1985
Language English
Contributing office(s) Patuxent Wildlife Research Center
Description 42-53
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Colonial Waterbirds
First page 42
Last page 53
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