Application of an Ecological Risk Assessment for Evaluation of Alternatives Considered for Restoration of Oysters in Chesapeake Bay: Background and Approach

ABSTRACT

Oyster populations in Chesapeake Bay, USA, declined precipitously over the past three decades, and on-going efforts to restore the native oysters to former abundance were considered to be ineffective. Maryland and Virginia natural resource agencies proposed the introduction of a non-native Asian oyster (Crassostrea ariakensis) that is resistant to diseases affecting the native oyster and well adapted to the Chesapeake Bay environment. Numerous stakeholders raised concerns about potential adverse consequences of an introduction of a non-native species into a new environment. In response, state and federal agencies determined that an Environmental Impact Statement (EIS) should be prepared to address the environmental consequences of such an introduction as well as of seven other oyster restoration alternatives, including several involving only the native oyster. Preparation of an Ecological Risk Assessment (ERA) of the proposed action as well as all alternatives was an integral element of EIS preparation. This series of articles describes several different analyses that contributed to and collectively comprised the ERA conducted as input to the EIS. The final article of this series in HERA describes how the ERA and EIS findings were taken into account in the final decision on the preferred restoration alternative by state and federal agencies.

Key Words:

• Chesapeake Bay
• ecological risk assessment
• estuarine ecosystem
• restoration

ACKNOWLEDGMENTS

The work reported on in the articles in this series was funded by the Maryland Department of Natural Resources, via cooperative agreements with the University of Maryland Center for Environmental Studies, and the Potomac River Fisheries Commission. Work on the ERA and the EIS was conducted in collaboration with the Maryland Environmental Service and performed under the direction and leadership of a management team comprised of Mr. Thomas O'Connell, Maryland Department of Natural Resources, Mr. Jack Travelstead, Virginia Marine Resources Commission, Mr. A. C. Carpenter, Potomac River Fisheries Commission, and Mr. Mark Mansfield, Norfolk District, USACE (CENAO). Technical direction was provided by a Project Delivery Team consisting of representatives of: Norfolk District, USACE (CENAO);

Virginia Marine Resources Commission; National Oceanographic and Atmospheric Administration (NOAA); Engineering Research and Development Center, USACE (ERDC); Atlantic States Marine Fisheries Commission (ASMFC); Maryland Department of Natural Resources (MD DNR); Potomac River Fisheries Commission; USEPA; and, U.S. Fish and Wildlife Service (FWS). The assessment relied on the considerable research on the Asian oyster that was carried out by individuals at various universities and government research laboratories. Many of those researchers provided insights into data interpretation and reviewed various parts of the assessment. The large number of contributors to the overall program are identified in the various appendices of the Final PEIS (USACE 2009) and their contributions to this effort are too numerous to summarize in a brief acknowledgment.

AUTHOR-DIRECTED PEER REVIEW

This manuscript was prepared under HERA's author-directed peer review process, wherein a manuscript's authors nominate proposed peer reviewers to HERA's Managing Editor for approval or revision. The following persons reviewed and approved the publication of this manuscript:

•	Mark Bryer, Director, Chesapeake Bay Initiative, The Nature Conservancy, Bethesda, MD, USA
•	William J. Goldsborough, Chesapeake Bay Foundation, Annapolis, MD, USA
•	Mike Fritz, U.S. Environmental Protection Agency, Annapolis, MD, USA

Notes

Introduction of the Asian oyster, the proposed action, would require placement of shell or other hard substrate on the Chesapeake Bay bottom on which the oysters would be planted; placement of such material in tidal waters requires that a CWA Section 404 permit be obtained from the USACE.

The ERAAG members included Todd Bridges (USACE), Chris Guy (FWS), Simeon Hahn (NOAA), and Barbara Okorn (USEPA).