Heavy metal concentrations in Black-tailed Gull (Larus crassirostris) chicks, Korea

- Black-tailed Gull chicks had different heavy metal concentrations at both colonies.
- Stomach contents of chicks had higher lead concentrations than regurgitated diets.
- Elevated lead levels on the lighthouse site might be associated with ingestion of paint chips.
- Lead and cadmium are transferred from the stomach contents to gull chicks.

The objectives of this study were to quantify concentrations of heavy metals in livers and stomach contents of Black-tailed Gull (Larus crassirostris) chicks from two islands in Korea. Iron and manganese concentrations were significantly higher in chick livers at Hongdo Island compared to Rando Islnad. In contrast, zinc, copper and cadmium concentrations were significantly higher at Rando Island than Hongdo Island. On Hongdo Island, Black-tailed Gull chicks at a lighthouse site had higher lead concentrations in livers and stomach contents than at a nearby reference site and stomach contents of Black-tailed Gull chicks had significantly higher lead concentrations than regurgitated diets. In Hongdo Island, manganese, lead and cadmium concentrations were significantly correlated between livers and stomach contents. Essential elements such as iron, zinc, manganese and copper concentrations from the present study were within the range reported for other seabird species including gulls. Livers of four individual gull chicks (13.3%) were at a level considered lead exposed (6-30 μg g−1 dry weight), but cadmium concentrations in all specimens were within the background level (<3 μg g−1 dry weight) for wild birds. Elevated lead concentrations on lighthouse site may be attributed to ingestion of paint chips and these concentrations may negatively affect chick behavior, growth and survival.