Potential modifications to the Predatory Bird Monitoring Scheme (PBMS): Second Report 2005

Abstract

The Predatory Bird Monitoring Scheme (PBMS) covers a long-term monitoring programme that examines the levels of pollutants in avian wildlife species in Britain.

The concentrations of organochlorine pesticides in many predatory bird species have declined to levels below those likely to have toxic effects. As a result, concerns about the environmental hazards posed by these pesticides have, at least in part, been superseded by those posed by new groups of chemicals. In the last review of the work of the PBMS (JNCC Report No. 320), a number of possible new activities that could be incorporated into the PBMS were specified. Any such refocusing of the PBMS within existing resources would require revision of the current sampling intensity of organochlorine pesticides in order to free resources for new monitoring. The first objective of this report was to assess the implications of reducing sampling intensity on the ability to detect long-term trends in the extent of wildlife contamination.

The specific aims of the report were to:

• quantify the effects of sampling frequency on the speed and precision with which longterm changes in patterns of contamination can be detected with statistical rigour,
• investigate how the monitoring of new compounds, particularly polybrominated diphenyl ethers (PBDEs) and polycyclic aromatic hydrocarbons (PAHs), can be incorporated into the PBMS,
• demonstrate how the link between environmental residue data and toxicity can be improved for PCBs, which are currently reported as total PCBs,
• demonstrate the ways in which the PBMS data can be used to identify hotspots of contamination, and so information on potential sources,
• examine the frequency with which unknown compounds occur in predatory birds and outline the ways in which they can be identified.

These five objectives form the basis of Sections 3–7 of the present report. A summary of the overall findings of the PBMS to date, and recommendations as to the way the PBMS can be adapted to widen its scope, and hence maximise its usefulness to regulators and policy-makers, is given in Section 8.