Long-term monitoring studies of pollutants on public lands: Bald Eagles in the Midwest
- Eagle Environmental Inc., Haslett, MI (United States)
The role of public agencies to monitor the populations of wildlife species with protected status is paramount to the recovery of these species. Since the early 1960s, the bald eagle (Haliaeetus leucocephalus) populations within the Midwest have been monitored to determine number of breeding pairs, nest occupancy, and success rates. In addition to the reproductive outcome studies, abandoned eggs, blood samples, and feather samples have been collected to determine concentrations of organochlorine pesticides, PCBs, and heavy metals. These surveys give an actual measure of population dynamics of a top-predator species in aquatic systems that integrates the effects of many different environmental pollutants. As concentrations of the organochlorine compounds have declined, bald eagle populations have increased in numbers and their reproductive success has improved. The recovery of this species has not been uniform however. In regions where DDT and PCB concentrations are still above thresholds associated with reproductive impairment, eagles still have impaired reproduction. These areas include the shorelines of the Great Lakes and Voyageurs National Park. Some areas such as the Chippewa National Forest have begun to show declines in reproduction due to density dependent factors. Recent proposals for ecosystem management and reclassification of the bald eagle have led to reduced emphasis for maintaining these long-term data sets. The utility and importance of maintaining surveys of top-predators that can give a measure of population-level effects of pollutants rather than an index will be discussed using examples from the Midwest.
- OSTI ID:
- 382725
- Report Number(s):
- CONF-9511137-; ISBN 1-880611-03-1; TRN: IM9645%%276
- Resource Relation:
- Conference: 2. Society of Environmental Toxicology and Chemistry (SETAC) world conference, Vancouver (Canada), 5-9 Nov 1995; Other Information: PBD: 1995; Related Information: Is Part Of Second SETAC world congress (16. annual meeting): Abstract book. Global environmental protection: Science, politics, and common sense; PB: 378 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effects of organochlorine contaminants on reproduction of bald eagles in the Saginaw Bay, Lake Huron
Environmental contaminants in bald eagles in the Columbia River estuary