Danville Dam 2018 Salvage Report: Results of the fish and freshwater mussel surveys following the removal of the Danville Dam on the Vermilion River

The Danville Dam on the Vermilion River (Wabash River drainage) in the city of Danville, Vermilion County, Illinois, was removed during the summer and autumn of 2018. During the project, 1 fish and 905 live individuals of 23 species of freshwater mussels were relocated. These included : 1 Smallmouth Bass (Micropterus dolomieu); 1 state-threatened Purple Wartyback (Cyclonaias tuberculata); 6 state-endangered Wavyrayed Lampmussel (Lampsilis fasciola); 1 state-endangered Rainbow (Villosa iris); 264 Mapleleaf (Quadrula quadrula); 217 Giant Floater (Pyganodon grandis); 130 Fragile Papershell (Leptodea fragilis); 91 Pink Heelsplitter (Potamilus alatus); 86 Plain Pocketbook (Lampsilis cardium). One side effect of dam removal is stranding, desiccation, and predation of mussels within the former impounded areas. In addition to the live individuals, 116 fresh-dead individuals representing 18 species were observed, including 1 fresh-dead Purple Wartyback; 2 fresh-dead Wavyrayed Lampmusselo1fresh-dead Rainbow; Nearly half of these individuals (e.g., 41 Giant Floater, 7 Mapleleaf, and 3 Plain Pocketbook) were observed during the last sampling eventand were found on the gravel bar that formed at the mouth of the North Fork. Given time, fishes and mussels should naturally recolonize the former impounded areas of the Danville Dam if habitat conditions are optimal and source populations are in close proximity.