2.3.2 Biologic Integrity
Large areas of undisturbed or minimally disturbed forest and wetland in the subwatershed, including the Baker Park Reserve and Painter Marsh, have been designated Regionally Significant Ecological Areas by the DNR. The Minnesota County Biological Survey (MCBS) determined that several areas in the subwatershed were of moderate or high biodiversity significance, including a tamarack swamp complex east of Katrina Lake; the wetland and upland areas surrounding Katrina Lake; and patches of maple-basswood and oak forest. The Baker Park Reserve and a large area in the lower subwatershed are part of a DNR-designated Metro Conservation Corridor. The lower subwatershed conservation corridor area is part of a much larger corridor that extends south into the Dutch Lake and Langdon Lake subwatersheds, eventually connecting with the Gale Woods Regional Park in Minnetrista.
The Minnesota Natural Heritage Information System lists several rare natural features in this subwatershed. These include bald eagle, a federally-listed threatened species; trumpeter swans, a state-listed threatened species; and American ginseng, a state species of special concern.
No fish or aquatic vegetation survey data is available for Katrina or Thies Lakes.
Biological sampling on Painter Creek was conducted as a part of the Upper Watershed Stream Assessment. Ten sites were sampled; only five yielded more than the 100 organisms typically needed to assure a statistically valid score. The F-IBI – an Index of Biotic Integrity identified to the organism’s family level – for nine of the ten sites fell into the “Fairly Poor” category. Macroinvertebrate family diversity was very low, primarily due to habitat limitations posed by the low stream gradient and numerous wetlands through which the creek flows. One site, just upstream of CR 110 about one-third of a mile upstream of the creek mouth, scored an F‑BI of “Good,” although that was based on a sample of only 10 organisms so it cannot be considered statistically valid. The score was based on a sampling of organisms at the site that as a family are relatively pollution intolerant. Additional sampling and identification of organisms to the species level would be necessary to adequately characterize the biological integrity of Painter Creek. Field staff conducting the sampling noted the presence of numerous carp in the lower reaches of the creek, and a few in the upper reaches.
A high density of wetlands is present in the subwatershed. A number of them were identified in the 2003 MCWD Functional Assessment of Wetlands (FAW) as having exceptional to high vegetative diversity and wildlife habitat potential as well as having high aesthetic values (see Figure13). Wetlands riparian to Katrina Lake as well as in-line wetlands on Painter Creek were noted as having high fish habitat potential.