2.3.2 Biologic Integrity
In the western subwatershed, much of the corridor between Black and Saunders Lakes, comprised of wetland and maple-basswood forest, has been identified by the DNR as a regionally significant area with outstanding ecological value (see Figure 7). This designation is based on an evaluation of the size of the area, the diversity of cover types, and its location. Most of this area has been incorporated into Gale Woods Regional Park by the Three Rivers Park District.
The western half of the subwatershed has been identified by the Department of Natural Resources as a Metropolitan Wildlife Corridor Focus Area, and by the City of Minnetrista as a natural resources corridor.
The most recent DNR fish survey of Langdon Lake was conducted in 1993. At that time the fish population was dominated by black bullhead, a fish that is typical of turbid waters, and various species of sunfish. No aquatic vegetation survey data is available, but by observation, the turbidity of the water limits the growth of aquatic macrophytes that in turn limits the fishery.
The 2003 MCWD Functional Assessment of Wetlands (FAW) evaluated wetlands within the subwatershed. Several were evaluated as having high vegetative diversity and wildlife habitat potential as well as having exceptional aesthetic and fish habitat values (see Figure 7, Figure 13, and Figure 14). The highest vegetative diversity was found in the wetland complex associated with Black Lake within the Gale Woods Regional Park and the wetlands riparian to Saunders Lake. The wetlands riparian to Saunders and Langdon Lakes were evaluated as having high fish habitat values.