Wildlife Damage Management, Internet Center for


Date of this Version



Proceedings of the 15th Wildlife Damage Management Conference. (J. B. Armstrong, G. R. Gallagher, Eds). 2013.


Nutria, (Myocaster coypus) a semi-aquatic rodent native to South America, were introduced to Maryland’s Eastern Shore near Blackwater National Wildlife Refuge (NWR) in 1943. By the 1970s, coastal wetlands on the Chesapeake Bay were deteriorating rapidly while nutria populations were expanding dramatically. In the mid-1990s, experiments conclusively linked marsh loss nutria herbivory, leading to the decision to eradicate nutria from the Delmarva Peninsula. A partnership of Federal, state and private organizations was convened and funding to investigate the feasibility of eradication was provided by the Nutria Control and Eradication Act of 2003. Following a brief investigation into the life history and local ecology of nutria in the Chesapeake Bay ecosystem, the partnership launched an operational plan to systematically eradicate nutria from Blackwater NWR and surrounding state and private lands in 2002. By 2006 nutria had been virtually eliminated from southern Dorchester County and the program was expanded. Since then, nutria has been removed from 160,000 acres from several watersheds in five counties in Maryland’s lower eastern shore facilitating the recovery of some damaged marshes. Detection methodologies are being developed and refined as the challenges of detecting low density populations increase search time. Nutria has since been detected in Delaware and Virginia and current efforts to delimit the extent of the population are underway. Once distribution is clearly defined, a systematic plan to remove remaining populations will be initiated.