Stressors to Impaired or Vulnerable Lakes (Based on Fish IBI)
Go to Section:- Overview
- Data Quality
- Data Organization
- Coordinate System
- Attributes
- Distribution - Get Data
- Metadata Reference
Section 1: Overview
Originator:DNR Division of Fish and Wildlife - Section of Fisheries
Title:
Stressors to Impaired or Vulnerable Lakes (Based on Fish IBI)
Abstract:
This layer summarizes the stressors to impaired or vulnerable lakes, which are identified from fish-based index of biological integrity (IBI) scores and aquatic life use judgements. The primary stressor(s) corresponding with the most recent assessment year for each lake are displayed; however, primary stressor(s) for all assessment years are included in the layer (i.e., multiple records for each lake may exist and corresponding data can be found in the attribute table).
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: species richness, community assemblage, and trophic composition. 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. Individual fish-based IBI scores and metrics can be viewed at Lakes with DNR Fisheries IBI Scores.
Aquatic life use judgements are made for individual lakes on a rotation occurring approximately once every 10 years as part of Minnesota Pollution Agency’s watershed assessment process. The fish IBI is a tool used for assessing lake impairment as part of Minnesota's 303(d) Impaired Waters assessments. Individual aquatic life use judgements can be viewed at Lakes with Aquatic Life Use Judgement (Based on Fish IBI).
Lakes that are assessed as impaired or vulnerable to impairment undergo a formal and rigorous process that identifies stressors causing biological impairment. Potential stressors to aquatic life in lakes include eutrophication, physical habitat alteration, altered interspecific competition, temperature regime changes, decreased dissolved oxygen, increased ionic strength, pesticide application, metal contamination, and unspecified toxic chemical contamination. Each category is classified as a stressor, inconclusive, not a stressor, or not evaluated for each lake. More comprehensive stressor identification reports, organized by HUC 08 watershed, contain detailed stressor information for individual lakes and are published to the Minnesota Water Research Digital Library.
For more reference information, see (Section 5: Attributes -- Detailed Citation).
Purpose:
This layer provides a visual representation of impaired and vulnerable lakes and contains summarized stressor information, for the purposes of planning, mapping, and spatial/temporal analysis. For each lake, the primary stressor(s) from the most recent assessment year are displayed by color; primary stressor(s) from previous assessment years can be accessed through the attribute table.
Time Period of Content Date:
05/01/2026
Currentness Reference:
Re-delineations and edits are frequent and occur as needed.
Progress:
In work
Maintenance and Update Frequency:
Annually
Spatial Extent of Data:
Statewide
Bounding Coordinates:
-97.23
-89.53
49.37
43.5
Place Keywords:
Minnesota, border waters
Theme Keywords:
Hydrography, Water, Lakes, Inland Waters, IBI, Index of Biotic Integrity, Impairment, Stressor Identification, Clean Water, WRAPS, Watershed Restoration and Protection Strategies
Theme Keyword Thesaurus:
Access Constraints:
None
Use Constraints:
None
Contact Person Information:
Derek Bahr,
Lake IBI Research Scientist
Minnesota DNR - Fisheries
1601 Minnesota Drive
Brainerd,
MN
56401
Phone: 218-203-4310
Email: derek.bahr@state.mn.us
Section 2: Data Quality
Attribute Accuracy:
Logical Consistency:
Completeness:
Data exist statewide, excluding lake classes 1-19 (in far northeastern MN). Most lakes < 100 acres are also excluded.
Horizontal Positional Accuracy:
Polygons have been improved by on-screen digitizing over DOQ and FSA imagery.
Vertical Positional Accuracy:
N/A
Lineage:
The lake polygons are derived from the DNR Hydrography - All Water Features feature class of the DNR Hydrography SDE Dataset. See metadata for DNR Water Features for more detail.
Section 3: Spatial Data Organization (not used in this metadata)
Section 4: Coordinate System
Horizontal Coordinate Scheme:
Universal Transverse Mercator
UTM Zone Number:
15
Horizontal Datum:
NAD83
Horizontal Units:
meters
Vertical Datum:
not applicable
Vertical Units:
not applicable
Depth Datum:
not applicable
Depth Units:
not applicable
Section 5: Attributes
Overview:
env_ibi_lakes_stressors (feature class attribute table): DOW, Lake_Name, and Fisheries_Area are derived from and consistent with the DNR Hydrography - All Water Features feature class of the DNR Hydrography SDE Dataset. See DNR Hydrography - All Water Features The remaining attributes are specific to this layer. This layer displays the most recent primary stressor(s) for each lake, but records of previous primary stressor(s) are also included (where applicable).
Detailed Citation:
For more detailed information about the fish-based IBI and stressor identification, consult the following sources:
Bacigalupi, J., D. F. Staples, M. T. Treml, and D. L. Bahr. 2021. Development of fish-based indices of biological integrity for Minnesota lakes. Ecological Indicators 125:107512.
https://www.dnr.state.mn.us/waters/surfacewater_section/lake_ibi/index.html
Table Detail:
env_ibi_lakes_stressors - feature class table (DNR Fisheries)| Field Name | Valid Values | Definition | Definition Source |
|---|
| DOW | - | Waterbody ID per DNR Ecological and Water Resources (EWR) Division's LAKESDB database; the DOWLKNUM may end in"00" (entire basin) or "01","02", etc. (sub-basin) | DNR EWR LAKESDB |
| Lake_Name | - | Public Water (Lake) Name | DNR EWR LAKESDB |
| Watershed_Name | - | HUC08 Watershed Name | DNR EWR LAKESDB |
| Fisheries_Area | - | DNR Fisheries Administrative Areas (Fisheries Office) | bdry_dnr_fisheries_admin.gdb\dnr_fisheries_admin |
| Assessment_Year | enumerated | Year of aquatic life use assessment | DNR Fisheries IBI Database (J. Bacigalupi) |
| 2015-Present | Year assessment occurred | |
| FIBI_Assess_Cycle | enumerated | Cycle of aquatic life use assessment | DNR Fisheries IBI Database (J. Bacigalupi) |
| 1+ | Cycle assessment occurred | |
| Candidate_Stressors | enumerated | Primary Stressor(s) | DNR Fisheries IBI Database (J. Bacigalupi) |
| E | Eutrophication | |
| EH | Eutrophication, Physical Habitat Alteration | |
| EHA | Eutrophication, Physical Habitat Alteration, Altered Interspecific Competition | |
| ETD | Eutrophication, Temperature, Dissolved Oxygen | |
| H | Physical Habitat Alteration | |
| HA | Physical Habitat Alteration, Altered Interspecific Competition | |
| HTD | Physical Habitat Alteration, Temperature, Dissolved Oxygen | |
| TD | Temperature, Dissolved Oxygen | |
| N | No Candidate Identified | |
| Eutro_All | enumerated | Eutrophication - All Categories | DNR Fisheries IBI Database (J. Bacigalupi) |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Eutro_Watershed | enumerated | Eutrophication - Watershed Inputs | DNR Fisheries IBI Database (J. Bacigalupi) |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Eutro_Internal | enumerated | Eutrophication - Internal Loading | DNR Fisheries IBI Database (J. Bacigalupi) |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Phys_Hab_All | enumerated | Physical Habitat Alteration - All Categories | DNR Fisheries IBI Database (J. Bacigalupi) |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Phys_Hab_Shore | enumerated | Physical Habitat Alteration - Riparian Land/Shoreline Disturbance | DNR Fisheries IBI Database (J. Bacigalupi) |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Phys_Hab_Spp | enumerated | Physical Habitat Alteration - Non-native Species Affecting Habitat | DNR Fisheries IBI Database (J. Bacigalupi) |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Phys_Hab_Plant | enumerated | Physical Habitat Alteration - Aquatic Plant Habitat Limited | DNR Fisheries IBI Database (J. Bacigalupi) |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Phys_Hab_Anth_Con | enumerated | Physical Habitat Alteration - Anthropogenic Connectivity Concerns | DNR Fisheries IBI Database (J. Bacigalupi) |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Phys_Hab_Nat_Con | enumerated | Physical Habitat Alteration - Naturally Limited Connectivity | DNR Fisheries IBI Database (J. Bacigalupi) |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Phys_Hab_Nat_Lim | enumerated | Physical Habitat Alteration - Naturally Limited Habitat Diversity | DNR Fisheries IBI Database (J. Bacigalupi) |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Alt_Int_Com_All | enumerated | Altered Interspecific Competition - All Categories | |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Alt_Int_Com_Spp | enumerated | Altered Interspecific Competition - Non-native Species | DNR Fisheries IBI Database (J. Bacigalupi) |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Alt_Int_Com_Mgmt | enumerated | Altered Interspecific Competition - Fish Management and Angling | DNR Fisheries IBI Database (J. Bacigalupi) |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Temp_Reg_Changes | enumerated | Temperature Regime Changes | DNR Fisheries IBI Database (J. Bacigalupi) |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Decreased_DO | enumerated | Decreased Dissolved Oxygen | DNR Fisheries IBI Database (J. Bacigalupi) |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Inc_Ion_Str | enumerated | Increased Ionic Strength - Chloride | DNR Fisheries IBI Database (J. Bacigalupi) |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Pesticide_App | enumerated | Pesticide Application | DNR Fisheries IBI Database (J. Bacigalupi) |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Metal_Cont | enumerated | Metal Contamination | DNR Fisheries IBI Database (J. Bacigalupi) |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Unsp_Tox_Chem | enumerated | Unspecified Toxic Chemical Contamination | DNR Fisheries IBI Database (J. Bacigalupi) |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Hist_Wint_Inf | enumerated | Historic Winterkill Influences | DNR Fisheries IBI Database (J. Bacigalupi) |
| S | Stressor | |
| IC | Inconclusive | |
| NAS | Not a Stressor | |
| NE | Not Evaluated | |
| Other | - | Other Considerations | DNR Fisheries IBI Database (J. Bacigalupi) |
| SID_Link | - | Weblink to stressor identification report | DNR Fisheries IBI Database (J. Bacigalupi) |
| Easting | - | UTM Easting (X) of waterbody center | ESRI auto calculated |
| Northing | - | UTM Northing (Y) of waterbody center | ESRI auto calculated |
| Display | enumerated | Identifies most stressor identification report | DNR Fisheries IBI Database (J. Bacigalupi) |
| No | Not most recent stressor identification report | |
| Yes | Most recent stressor identification report | |
| Shape_Length | - | Perimeter of polygon | ESRI auto calculated |
| Shape_Area | - | Area of polygon | ESRI auto calculated |
Section 6: Distribution
Publisher:
Minnesota DNR - Division of Fish and Wildlife
Publication Date:
05/01/2025
Contact Person Information:
Zeb Thomas,
GIS Data Systems Coordinator
Minnesota DNR - GIS
500 Lafayette Rd
Saint Paul,
MN
55155
Phone: 651-259-5637
Email: zeb.thomas@state.mn.us
Distributor's Data Set Identifier:
env_ibi_lakes_stressors.gdb\env_ibi_lakes_stressors
Ordering Instructions:
Please visit the download page for this dataset on the Minnesota Geospatial Commons website using the web link below (Online Linkage). Online Linkage: I AGREE
to the notice in "Distribution Liability" above. Clicking to agree will either begin the download process, link to a service, or provide more instructions. See "Ordering Instructions" above for details.
Section 7: Metadata Reference
Metadata Date:
05/01/2026
Contact Person Information:
Derek Bahr,
Lake IBI Research Scientist
Minnesota DNR - Fisheries
1601 Minnesota Drive
Brainerd,
MN
56401
Phone: 218-203-4310
Email: derek.bahr@state.mn.us
Metadata Standard Name:
Minnesota Geographic Metadata Guidelines
Metadata Standard Version:
1.2
