Urban river pollutants suppress wild bird development

http://www.eurekalert.org/pub_releases/2014-04/cu-urp042514.php

PUBLIC RELEASE DATE: 29-Apr-2014

Contact: Steve Ormerod
Cardiff University
Urban river pollutants suppress wild bird development

New research indicates that hormone disrupting pollutants are affecting the health and development of wild birds nesting along the urban rivers of South Wales.

Findings published today in the Environmental Toxicology and Chemistry journal reveal that chicks of the Eurasian Dipper – a river bird that feeds exclusively on insects and fish in upland streams – are underweight compared to their rural counterparts. Also of concern is that birds nesting in urban rivers have altered hormone levels, and are hatching fewer female chicks than those nesting along rural rivers, which could have negative implications for the population's breeding and survival.

Data obtained by a team of scientists from Cardiff University, working in collaboration with the Universities of Saskatchewan and Exeter, and the Natural Environment Research Council, suggest that urban contaminants such as PCBs (polychlorinated biphenyls) and PBDE flame-retardant chemicals (polybrominated diphenyl ethers) acquired through their food are to blame. Results showed a strong correlation between contamination by PBDEs and PCBs with depressed thyroid hormone levels in chicks – one thyroid hormone was 43% lower in chicks from urban rivers than those rural rivers.

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