Nestling of seagull as an indicator of recent chemical contamination in the marine environment

Abstract

Seabirds can be useful indicators for current contamination and long-term trends in the marine environment. To investigate the contamination status and accumulation characteristics of persistent organic contaminants, eggs and dead nestlings (ages: < one week, about three weeks, > one month) were collected from a breeding site of black-tailed gulls located in the southern part of Korea. In addition, dead adult gulls were collected nearby coastal regions. The egg content and liver tissues of nestling and adult gulls were subjected to the analysis of persistent organic pollutants including polychlorinated biphenyl (PCBs), organochlorine pesticides (DDTs, HCHs, chlordans and hexachlorobenzene), polyborominated diphenyl ehters (PBDEs), and hexabromocyclododecanes (HBCDs). The concentration of contaminants in nestling was highest immediately after hatching (< one week) due to maternally deposited contaminants in eggs, then rapidly declined as nestlinggrew (three weeks and one month of age). It is likely due to dilution of contaminant body burden through growth in size (namely, bio-dilution effect). Overall, isomeric (or congener) compositions were similar across all age groups with thehigh abundance of persistent isomer (or congener) of each compound such as PCB-153, β-HCH, DDE, PBDE-47, and