Lakes with Fish-based IBI Scores (Most Recent IBI Survey)

This layer shows the <b>Fish-based Index of Biotic Integrity (IBI) Scores</b> for MN lakes as calculated by DNR Fisheries. Scores range from 0-100, with higher scores indicating higher biotic integrity. Attributes correspond to the <U>most recent IBI survey</u> for each lake.<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). <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>. <br/><br/><b>Related table:</b> <i>fsh_ibi_all_surveys </i><br/>IBI scores for additional years can be found in this table.<br/><br/><b>To access related table records:</b><br/><li>Open the layer attribute table and select a lake polygon record</li><br/><li>From the <i>Related Table dropdown (2nd icon on bar just above table)</i>, choose table <b>Lake IBI Scores: To IBI Scores - All Surveys</b></li><br/> <li> The related table will open and the corresponding records for the selected lake will be highlighted.</li><br/> <li>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 <i>Related Tables dropdown (2nd icon)</i>, choose table <b>Lake IBI Scores: Back to IBI Lakes</b>) </li><br/><br/>You can also access scores from all years by clicking on the lake of interest with the <b>Identify Tool</b> and expanding the related tabular information.