, Volume 12, Issue 1, pp 141–151

Assessing Temporal Trends in Contaminants from Long-term Avian Monitoring Programs: The Influence of Sampling Frequency


DOI: 10.1023/A:1022542408144

Cite this article as:
Hebert, C.E. & Chip Weseloh, D. Ecotoxicology (2003) 12: 141. doi:10.1023/A:1022542408144


The effect of sampling frequency on the detection of statistically significant temporal trends in egg contaminant levels was examined using data from the Great Lakes Herring Gull Monitoring Program. Decreased identification of statistically significant trends was apparent in the sampling regimes where samples were collected less frequently. When statistically significant declines were observed, sampling at two and four year intervals resulted in the trend being identified later than with annual monitoring. The design of monitoring programs must balance costs and data quality. Programs should ensure that the data collected are adequate to address critical questions.

environmental monitoringcontaminant trendsPOPswildlifeherring gull

Copyright information

© Kluwer Academic Publishers 2003

Authors and Affiliations

  1. 1.Canadian Wildlife ServiceNational Wildlife Research CentreHull, QCCanada, K1A 0H3
  2. 2.0Canadian Wildlife Service, Ontario RegionDownsview, ONCanada