Northern Riffleshell and Clubshell 2015 Monitoring Results

In 2015, staff from the Illinois Natural History Survey continued to monitor translocated populations of two federally-endangered freshwater mussel species in the Vermilion River basin (Wabash River drainage). Between 2010 and 2014, a total of 2,099 Northern Riffleshell (Epioblasma rangiana) and 1,766 Clubshell (Pleurobema clava) have been translocated to eight sites in the Vermilion River basin, Champaign and Vermilion counties, Illinois. These translocated animals have been monitored seasonally since being moved to Illinois. For the 2015 calendar year, 36% (716) of the 1,991 available Northern Riffleshell were encountered, and of those physically examined, 61% (54 of 88) were alive. Conversely, 77% (1,359) of the 1,758 available Clubshell were encountered, and of those examined, 82% (106 of 129) were alive. The encounter and survival rates from the raw data collected in 2015 were comparable to previous years in Illinois. Throughout the duration of the project, both Northern Riffleshell and Clubshell have had higher encounter rates in the spring and autumn than summer. This relocation project is being funded, in part, by a natural resource damage assessment settlement (Hegeler Zinc—Lyondell Basell Companies) to the U.S. Fish and Wildlife Service and to the State of Illinois, and by the U.S. Fish and Wildlife Service’s Ohio River Basin Fish Habitat Partnership.IDNR Division of Natural HeritageU.S. Fish & Wildlife Serviceunpublishednot peer reviewe

Northern Riffleshell and Clubshell Reintroduction Project - Summary of Activities for 2017

In 2017, staff from the Illinois Natural History Survey continued to monitor translocated populations of two federally-endangered freshwater mussel species in the Vermilion River basin (Wabash River drainage). Through 2017, a total of 3,699 Northern Riffleshell (Epioblasma rangiana) and 4,166 Clubshell (Pleurobema clava) have been translocated to the Middle Fork and Salt Fork Vermilion rivers in the Vermilion River basin, Champaign and Vermilion counties, Illinois, and these translocated animals have been monitored since being moved to Illinois. This end-of-the-year report summarizes the activities for the 2017 calendar year, and includes two reprints and a galley of a third paper summarizing data from this project. This relocation project is being funded, in part, by a natural resource damage assessment settlement (Hegeler Zinc—Lyondell Basell Companies) to the U.S. Fish and Wildlife Service and to the State of Illinois, and by the U.S. Fish and Wildlife Service’s Ohio River Basin Fish Habitat Partnership.The Illinois Department of Natural Resources, Natural Resources Damage Assessment, Restoration, and Implementation Project Number: IDNR-NRDA1504unpublishednot peer reviewedOpe

Northern Riffleshell and Clubshell Reintroduction Project Summary of Activities from 2014-2018

Staff from the Illinois Natural History Survey participated in a joint project with the Illinois Department of Natural Resources and the U.S. Fish and Wildlife Service to reintroduce the federally-endangered Northern Riffleshell (Epioblasma rangiana) and Clubshell (Pleurobema clava) to Illinois. A salvage project in the Allegheny River, Pennsylvania provided an opportunity for the translocation of both species. Since the first translocation in 2010, a total of 3,699 Northern Riffleshell and 4,166 Clubshell were collected from the Allegheny River at the U.S. Highway 62 (=Hunter Station) Bridge, Tionesta Township, Forest County, Pennsylvania, and translocated to suitable habitat at eight sites in the Vermilion River basin (Wabash River drainage) in Champaign and Vermilion counties, Illinois. Our monitoring data suggest the Clubshell translocation has been more successful than the Northern Riffleshell translocation. We estimate that Clubshell have approximately 5 times greater survival rates compared to Northern Riffleshell. As a result, very few Northern Riffleshell likely remain. Survival also varied among translocation sites, likely a result of localscale differences such as substrate or gradient. Regardless, high discharge events posed the greatest threat for the long-term success of this project, as survival was significantly decreased following periods of abnormally high flows. Consequently, we believe that repeated translocations of individuals over a period of several years across several sites could be implemented to reduce the overall risk of failure due to high discharge events or local-scale differences. This translocation project is being funded, in part, by a natural resource damage assessment settlement (Hegeler Zinc—Lyondell Basell Companies) to the U.S. Fish and Wildlife Service and to the State of Illinois.Illinois Department of Natural Resources’ Office of Resource Conservation, Contaminant Assessment Sectionunpublishednot peer reviewedOpe