Dykstra, C.R., et al. 2010. Contaminant concentrations in Bald Eagles nesting on Lake Superior, the upper Mississippi River, and the St. Croix River. J. Great Lakes Res. 36:561-569.
Cheryl Dykstra and her colleagues measured contaminant concentrations in Bald Eagle nestlings collected from three regions over the past two decades. Their study documents a steady decrease in concentrations of the persistent organochlorines DDE and total PCBs, as well as mercury, along the Lake Superior shoreline. Lake Superior nestlings had the highest concentrations of DDE. Concentrations of total PCBs were highest along the industrial areas of the Mississippi and Lower St. Croix rivers, and levels of mercury were greatest along the upper St. Croix River. Levels of all three contaminants were below those associated with significant impairment of reproduction, and observed reproductive rates were indicative of a healthy population.
Cheryl Dykstra is an independent researcher and self-employed wildlife consultant in West Chester, Ohio. Her training in wildlife ecology includes a B.S. degree from Calvin College in Grand Rapids, MI and M.S. and Ph.D. degrees in Wildlife Ecology from the University of Wisconsin-Madison. Her work now focuses on evaluating the effects of urbanization on the ecology of raptors in suburban areas of southwestern Ohio.