Efforts to Document the Federally Endangered Ring Pink (Obovaria retusa) within Mammoth Cave National Park in Edmonson County, Kentucky, 2016

Lewis Environmental Consulting, LLC

Lewis Environmental Consulting, LLC (LEC) of Murray, Kentucky was contracted by the U.S. Fish and Wildlife Service (USFWS), Kentucky Field Office in Frankfort, Kentucky to verify the existence of live Ring Pink mussels in the section of the Green River that runs through Mammoth Cave National Park in Edmonson County, Kentucky. The federally endangered Ring Pink mussel (Obovaria retusa) has been found alive within the Green River within the park boundaries, including one live individual collected in 2015, however only dead shells have otherwise been collected in recent years. Also, much of the sampling within Mammoth Cave National Park has been accomplished by sampling shallow areas or searching muskrat middens, and areas requiring diving have not been sampled. The section of the Green River within Mammoth Cave National Park upstream of Green River Ferry, is one of the few sections of the Green River that has never been impacted by dams, industry, or any type of development. This section of the Green River has remained in its natural state through all the various impacts that have altered many other reaches of the Green River system. Based on the history of the Green River system, the river section within Mammoth Cave National Park remains as one of the few, and most likely sections of river, which may have sustained a population of live Obovaria retusa. Four sites within the park were qualitatively sampled in the 2016 effort. Overall, 28 species were collected alive and three additional species were observed as weathered dead shells. Two live federally endangered species were observed at the sample sites including Cyprogenia stegaria and Plethobasus cyphyus. Although the 2016 mussel survey of the Green River within Mammoth Cave National Park was unsuccessful in documenting the existence of live Ring Pink (Obovaria retusa) within the national park boundaries, the likelihood of live Obovaria retusa residing in this stretch of the Green River remains promising. Ten historic locations have been documented within the Park as having records of live and/or dead Obovaria retusa. Three of the historic locations were sampled in 2015, and an additional two were sampled in 2016. Given the success of locating a live Obovaria retusa in 2015 and the large amount of unsampled habitat, additional search effort should be expended throughout the park to verify whether or not other live individuals may still be present. Additionally, the section of the Green River through Mammoth Cave National Park had not been sampled by diving before the efforts by LEC, therefore additional opportunities to locate new mussel concentrations and species are abundant.