Indigo Tunnel Bat Habitat - Installation of Bat Gates, Interim Closure
The National Park Service, Chesapeake and Ohio Canal NHP, will install metal gates at each portal of the Indigo Tunnel of the abandoned Western Maryland Railroad (WMRR), near Little Orleans, MD and Mile 140 of the park. This is an effort to help prevent the spread of White Nose Syndrome (WNS), by humans, to known bat colonies living in the Indigo Tunnel. A survey of the tunnel by Maryland Department of Natural Resources, Wildlife and Heritage Division (DNR) scientists and park natural resources staff was conducted on March 31, 2010. While WNS was not visual detected at Indigo Tunnel, WNS has been detected as close as 20 miles away. WNS is a non-curable disease that has been spreading among bat colonies throughout the northeastern United States and is decimating the bat population. While the disease is still being studied by scientists, closing the tunnel from unauthorized human entry will reduce the potential for contamination and spreading of the disease by humans. Many caves and abandoned mines are being closed along the Appalachian Mountains to prevent the spread of the disease.
The Indigo Tunnel has been identified by DNR as one of the largest bat hibernacula in the state of Maryland. It is the home for numerous state listed endangered and threatened species of bats and the Federally Listed Indiana bat.
On-going scientific monitoring will need to occur to determine appropriate recommendations for the protection of bats in the future. Periodic reviews will be conducted by scientific experts to determine if access to the tunnel by the general public is appropriate.
The Indigo Tunnel has been under NPS ownership since 1980. It has never been open to the public; however, the attempts to secure the tunnel have frequently been compromised by the public. The bat gates will be constructed to prevent unauthorized tunnel access, and meet standards set forth by the scientific community to allow freedom of access for bats and other animals which live in the tunnel. The gates will not restrict air movement within the tunnel, as a change to the tunnel climate conditions could also have a detrimental effect on the bats.
The gates will be made of steel and have fixed horizontal louvers. The gates will be anchored into the tunnel's bedrock walls just beyond the portals. Every effort will be made to avoid impacts to the historic portal during installation. Free standing informational signage will be placed in the center of each portal regarding bat habitat and WNS.
The closing of the tunnel during bat hibernation season had been identified as a component for the Western Maryland Rail Trail environmental assessment, due to be undertaken in 2010. That project will address impacts associated with conversion of the abandoned Western Maryland railroad to a rail trail. However, WNS makes the protection of the bat colonies within the Indigo Tunnel a standalone concern that needs to be addressed immediately. This compliance package will be referenced within the WMRT environmental assessment.
The park's Interdisciplinary Team reviewed the project for impacts to natural and cultural resources. The project does not pose any serious or long-term effects to the environmental, historical, cultural, archeological, or visual resources. It meets categorical exclusion #C.17 – Construction of fencing enclosures or boundary fencing posing no effect on wildlife migrations.
In consultation with the Maryland Historical Trust (State Historic Preservation Officer), as required by Section 106 of the National Historic Preservation Act, the project was reviewed for impacts to cultural resources. No adverse impacts are anticipated as a result of this project and the project is consistent with the Secretary of Interior's Standards for Rehabilitation and the accompanying guidelines.
For further information about this project, please contact Chief of Resources, Chesapeake and Ohio Canal NHP, 1850 Dual Highway, Suite 100, Hagerstown, MD 21740