Abstract
Two studies evaluated the utility of great blue herons (Ardea herodias; GBH) as representative bioindicators for watersheds in the northeastern United States and the efficacy of using LA-ICP-MS technology with bird feathers. Trace metal concentrations and d15N values in items collected in 2011 from active heronries in more urbanized areas of the Hudson River valley, NY were not significantly enriched relative to items from more rural heronries. Reproductive success was not negatively correlated with trace metal levels and sewage pollution. Feathers acquired from GBH museum specimens reflected increasing Pb concentrations in northeastern watersheds until the mid-20th century, but Cd trends were not statistically significant. A depletion of d15N values may have demonstrated the increasing influence of man made fertilizer in northeastern watersheds through the latter half of the 20th century. Sampling issues and high variability limit the usefulness of GBH as bioindicators, but LA-ICP-MS is recommended for use on bird feathers.