These are animal and plant species that live in Mercer County are considered of special concern.

Great white heron, marsh wren, bald eagle, least bittern, osprey, king rail and Virginia rail.

Massasauga rattlesnake.

Three ridge mussel, snuffbox, long-solid, two forms of white heelsplitter, Eastern pondmussel, round hickorynut, clubshell, round pigtoe, rabbitsfoot and pistolgrip mussel.

Brook stickleback, bluebreast darter, spotted darter, tippecanoe darter, Ohio lamprey, mountain brook lamprey, brook silverside, warmouth, river redhorse, mountain madtom, brindled madtom, longhead darter and central mudminnow.

Small flower false foxglove, broad-leaved water plantain, short-awn meadow foxtail, lesser tussock sedge, few seeded sedge, prairie sedge, cat-tail sedge, yellow lady's slipper, elliptic spike-rush, square-stem spike rush, downy willowherb, queen-of-the-prairie, Torrey's sedge, bushy naiad, holly-leaved naiad, fog-fruit, bog bluegrass, Illinois pondweed, red-head pondweed, autumn willow, meadow willow, water bulrush, Pursh's goldenrod, American columbo and highbush cranberry.