This IBA includes the St. Marys River corridor and the neighboring Grand Lake, as such representing elements of both the Great Lakes and the Mississippi River watersheds. It also includes the St. Marys Fish Hatchery on the east side of the lake and the Mercer Wildlife Area on the west. Grand Lake is Ohio's largest inland lake, functioning as a man-made reservoir with an outlet flowing west to Beaver Creek and eventually to the Wabash River in the Mississippi watershed. The St. Marys River originates just east of Grand Lake, flowing north and west to eventually join the St. Joseph River in Indiana to form the Maumee River, which flows back into Lake Erie. Rare species include state listed swamp cottonwood, catchfly grass (only site in Ohio), lake cress, raven's-foot sedge, pigeon grape, and pugnose minnow. The St. Marys River corridor is a hydrologically intact river valley with a remaining riparian corridor, many oxbows and much floodplain forest and wetlands, in great contrast to most of surrounding farmlands. This corridor is the single most forested corridor in west-central Ohio. High quality sites along the corridor include the Barber-Werner Oxbow, Speckman Woods, and The Thoroughfare.
The St. Marys River corridor contains unique and rare habitats and species in the most agriculturally developed part of state. Barber-Werner Road Oxbow is a high quality site of a rare habitat type-floodplain forest. Forty-two species were recorded from this site alone by the nominator in 1988 with high numbers during migration in spring.
The Thoroughfare has a large amount of good quality wetland, riparian, and forest habitat in an area of the state that has had most of the native habitats removed.
It includes migratory stopover and feeding area for forest and wetland species, including some state-listed species. Large numbers of waterfowl use the area when migrations and seasonal floods coincide.
The 160 acres of the St. Marys Fish Hatchery ponds attract diving and puddle ducks during migration peaks, as well as shorebirds and wading birds during times of peak mudflat exposure in spring and fall.
Conservation and improvement of the St. Marys River corridor is a difficult but critical priority if we are to save habitat for many species of birds, as well as other plants and animals. This is a relatively heavily forested belt that runs through open row-crop farmland. Although the surrounding area is on the lowest gradient river in state and is very difficult to drain, the whole riparian corridor is relatively unrecognized for its importance and is subject to gradual conversion through logging, clearing for farming, draining, channelization, siltation, ete. The corridor needs to be part of larger conservation effort to preserve the forests and wetlands still remaining on Grand Lake and the St. Marys. Water quality of the lake especially is degraded by both agricultural run-off and residential pollution. The St. Marys protects Ft. Wayne, Indiana and other areas downstream from floods. Pollution (serious), habitat conversion, and hydrologic changes are minor threats.
Owner: Various Owners