Lakes with DNR Fisheries IBI Scores

This layer shows the <b>Fish-based Index of Biological Integrity (IBI) Scores</b> for MN lakes as calculated by DNR Fisheries. Scores range from 0-100, with higher scores indicating higher biological integrity. The score corresponding with the <u>most recent IBI survey</u> with high quality data for each lake is displayed; however, scores for all surveys are included in the layer (i.e., multiple records for each lake may exist and corresponding data can be found in the attribute table).<br/><br/>An IBI is a biologically-based, multi-metric method for measuring the integrity of aquatic systems. Minnesota DNR Fisheries has developed four fish-based lake IBIs that incorporate fish data collected by various methods (trap nets, gill nets, shoreline seines, and backpack electrofishing units) into 8-15 metrics in three categories: <b>species richness, community assemblage, and trophic composition </b> <i>(see Section 5: Attributes)</i>. Each metric represents an aspect of the biological assemblage structure, function, or other measurable characteristic that changes in some predictable way with increased human-induced stress. Fish-based IBI scores respond to differences in land use patterns, trophic state, and aquatic vegetation.<br/><br/>The fish-based IBI is a tool used for assessing lake impairment as part of Minnesota's 303(d) <i>Impaired Waters</i> assessments. The scores in this layer should be considered as '<u>preliminary</u>' until a lake is assessed (see <a href="https://resources.gisdata.mn.gov/pub/gdrs/data/pub/us_mn_state_dnr/env_ibi_lakes_fisheries/metadata/../../env_aquatic_life_use_judgement/metadata/metadata.html" target=_blank><b>Lakes with Aquatic Life Use Judgement (Based on Fish IBI)</b></a> layer for assessment information). Stressor identification is then completed for lakes assessed as impaired or vulnerable (see <a href="https://resources.gisdata.mn.gov/pub/gdrs/data/pub/us_mn_state_dnr/env_ibi_lakes_fisheries/metadata/../../env_ibi_lakes_stressors/metadata/metadata.html" target=_blank><b>Stressors to Impaired or Vulnerable Lakes (Based on Fish IBI)</b></a> layer for candidate stressors and associated information). <b>This dataset only includes lakes over 100 acres and within lake classes 22-43, with few exceptions for lakes very close to 100 acres</b>. Additional scores are added to this dataset annually. <br/><br/>For more reference information, see <i>(Section 5: Attributes -- Detailed Citation)</i>.