This layer shows the Fish IBI (Index of Biotic Integrity) Scores for MN lakes as calculated by DNR Fisheries. Scores range from 0-100, with higher scores indicating higher biotic integrity. Attributes correspond to the most recent IBI survey for each lake.An IBI (Index of Biotic Integrity) is a biologically-based, multi-metric method for measuring the integrity of aquatic systems. Minnesota DNR Fisheries Research has developed a fish-based lake IBI that incorporates fish data collected by various methods (trap nets, gill nets, shoreline seines, and backpack electrofishing units) into 8-15 metrics in three categories: species richness, community assemblage, and trophic composition (see Section 5: Attributes). 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 IBI scores respond to differences in land use patterns, trophic state, and aquatic vegetation.Validation studies indicate that the fish-based lake IBI scores function as a measure of fish community response to human disturbance across a gradient of lakes. Continuing work by DNR Fisheries will expand the application of this IBI to more lake types and will validate this tool as a viable method for assessing lake impairment as part of Minnesota's 303(d) Impaired Waters assessments. These scores should be considered as '' and are subject to change as the IBI tools are further developed and refined. This dataset only includes lakes over 100 acres and within lake classes 20-43, with few exceptions for lakes very close to 100 acres. Additional scores will be added to this dataset annually. For more reference information, see (Section 5: Attributes -- Detailed Citation). Related table: env_ibi_lakes_all_surveys_events_polygon_relate IBI scores for additional years can be found in this table.To access related table records:Open the layer attribute table and select a lake polygon recordFrom the Related Table dropdown (2nd icon on bar just above table), choose table Lake IBI Scores: To IBI Scores - All Surveys The related table will open and the corresponding records for the selected lake will be highlighted. Note: You can also select records from the related table and find the lakes that correspond to those records by reversing the process above (i.e., Choose Related Tables dropdown (2nd icon), choose table Lake IBI Scores: Back to IBI Lakes) You can also access scores from all years by clicking on the lake of interest with the Identify Tool and expanding the related tabular information.