HOW THE MADISON CAVE ISOPOD, ANTROLINA LIRA CAN SAVE THE PHREATIC AQUIFER

The Madison Cave Isopod, Antrolana lira Bowman 1964, is a free-swimming cirolanid isopod known to occur only within the carbonate-saturated waters of the phreatic karst aquifer of the Shenandoah Valley. The type locality was originally limited to two pools in Madison Cave and a small pool in an adjacent cave named Steger’s Fissure, both in Augusta County, Virginia. Because A. lira was threatened by human visitation to its only known habitat and by mercury pollution of the nearby South River, the taxon’s status as a threatened species was finalized in a rule issued by the U.S. Fish and Wildlife Service (USFWS) on 4 October 1982. Since that time, the range of A. lira has been extended through much of the Shenandoah Valley in Virginia and the eastern panhandle of West Virginia.

In 2009, GeoConcepts Engineering was contracted by The Conservation Fund to perform a karst survey of the 76-mile alignment of the Columbia Gas Transmission Pipeline through the Shenandoah Valley. The findings of this survey were among those used to develop the NiSource/Columbia Gas Multi-Species Habitat Conservation Plan. Included in the plan were a series of avoidance and minimization measures (AMMs) and best management practices (BMPs) designed to minimize impact to the taxon’s habitat, which were developed in teamwork with the USFWS. The primary goal of these measures was to prevent and/or minimize the incursion of sediment- and contaminant-laden water into the epikarst through surface features, eventually finding its way into the deep phreatic aquifer. The majority of reliable wells and perennial springs in karst-lands are dependent on the phreatic aquifer for their source water. Therefore, we suggest that the same AMMs and BMPs used to protect A. lira should be invoked even in places where the taxon does not occur in order to protect vital drinking water resources.