Geographic variation in blood plasma protein concentrations of young herring gulls (Larus argentatus) and Caspian terns (Sterna caspia) from the Great Lakes and Lake Winnipeg

Relative and total amounts of plasma protein fractions are affected by infe ctions, inflammation, and nutritional and physiological status, and are the refore important health indicators in free-living animals. Our objectives w ere: (1) to examine intercolony differences in plasma protein fractions in prefledgling gulls and terns; (2) to investigate relationships between plas ma proteins and other physiological measures such as weight loss, growth, a nd immune function; and (3) to examine potential associations between organ ochlorine exposure and plasma proteins. During 1992, blood was collected fr om 3-week-old herring gull (Larus argentatus) chicks from six sites on Lake s Superior, Huron, Michigan, Erie, and Winnipeg acid from 3-week-old Caspia n tern (Sterna caspia) chicks from five sites on Lakes Huron, Michigan, and Ontario. These sites provided a wide gradient of organochlorine contaminat ion. Plasma proteins were separated by high-resolution agarose gel electrop horesis and stained with Coomassie brilliant blue dye. Six major fractions were quantified: prealbumin, albumin, alpha-globulins, beta(1)-globulins, b eta(2)-globulins, and gamma-globulins. Total protein, prealbumin, albumin, and gamma-globulin concentrations and the albumin/globulin ratio did not di ffer among sites. Total protein, albumin, and the albumin/globulin ratio we re not decreased in birds experiencing food stress or weight loss. Intersit e differences were found in alpha- and beta-globulins. In gulls, beta(2)-gl obulins were positively associated with polychlorinated biphenyls (PCBs) an d 1,1-dichloro-2,2-bis(p-chlorophenyl)ether (DDE). In terns, PCBs were nega tively associated with alpha-globulins and positively associated with beta( 1)-globulins. Additional research is needed to identify individual proteins and elucidate causal relationships between the particular protein concentr ations and factors such as contaminants, growth, and condition. (C) 2000 El sevier Science Inc. All rights reserved.