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Joanna Burger, Michael Gochfeld, and Charles W. Powers Abstract: The United States and other developed countries are faced with restoring and managing degraded ecosystems. Degradation can include physical disruption (loss of habitat or changes in patch size), human disturbance, biological disruption (invasive species, diseases), or chemical/radiological exposures. Evaluating the relative effects of these stressors on ecological resources is the responsibility of managers, risk assessors, resource trustees, and ecologists (as well as economists). Evaluations of the degradation of ecological resources can be used for determining ecological risk, making remediation or restoration decisions, aiding stakeholders with future land decisions, and assessing natural resource damages. Department of Energy (DOE) lands provide a useful case study for developing a conceptual model for examining degradation of ecological resources in light of past pr present land uses and natural resource damage assessment (NRDA). We suggest that NRDA considerations should be incorporated into the cleanup and restoration phase to reduce the ultimate NRDA costs, and hasten resource recovery. While the formal NRDA legal determination of injuries is limited to damages for trust resources lost, injured or destroyed by chemical/radiological releases since 1980, the restoration and pre-assessment phase could incorporate ecosystem recovery as well as injuries due to these releases. For most DOE lands there were multiple releases, of multiple radionuclides and chemicals, over a wide geographical area, in contrast to a chemical or oil spill that usually has one release event at one site. The lands that DOE purchased for its mission over 50 years ago ranged from relatively undisturbed to heavilyimpacted farmland. Thus the degree of impact (or injury) that occurred once DOE occupied these lands varied markedly from regeneration of natural ecosystems (a positive benefit) to increased exposure to several stressors (negative effects). During the time of the DOE releases, other changes occurred on the lands, including ecosystem recovery because of the removal of farming, grazing, and residential occupation, and the cessation of human disturbance. Thus, the injury to natural resources that occurred as a result of chemical and radiological releases occurred on top of ecosystem recovery. Both spatial (size and dispersion of patch types) and temporal (past/present/future land use and ecological condition) components are critical aspects of resource evaluation, restoration, and NRDA. For many DOE sites, integrating natural resource restoration with remediation to reduce or eliminate the need for NRDA could be a win-win situation for both responsible parties and natural resource trustees by eliminating costly NRDAs by both sides, restoring natural resources to a level that satisfies the trustees, while being cost-effective for the responsible parties. It requires integration of remediation, restoration, and end-state planning to a greater degree than is currently done at most DOE sites.
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