- What is the Fishes of Minnesota Mapper?
The Fishes of Minnesota Mapper is a quick browser-based map interface that allows you to see the distribution of fish species across the state of Minnesota. It displays data from the Fishes of Minnesota database -- a comprehensive compilation of data from a variety of sources.
See Data Sources and Dates for current record counts and dates.
- Why are fish surveys conducted?
Fish surveys are conducted to:
- Document the abundance and spatial distribution of different fish species in Minnesota waters
- Estimate species diversity and richness by waterbody, watershed, etc.
- Document the occurrence of rare/endangered and exotic/invasive species
- Determine habitat preferences for different fish species
- Note spawning conditions, growth rates, diseases, etc.
- Collect unique specimens (vouchers) for museum archives
- Monitor the quality of water and habitats over time and space
For more information, see:
- Why are many waterbodies surveyed in some counties, but not in others?
When counties contain little suitable habitat, fewer surveys are conducted there. Waterbodies that are popular for fishing or recreation may receive more surveying effort than those that do not. Also, lakes having one or more species formally managed by DNR Fisheries (through stocking, regulations or population structure) are subject to regular surveys.
- Why are species lists longer for some areas than for others?
- Different habitats and environmental conditions (e.g., water temperature, flow velocity, substrate, prey species, etc.) naturally support different types of species. Lakes and streams with similar environmental conditions often support similar fish communities.
- Species types and counts in the same lake and location may differ from survey to survey due to changes in season, hydrologic conditions, water quality, etc.
- Fish surveys are designed to meet a number of different objectives using a variety of survey techniques. These techniques may 'target' differently species unequally, leading to an under-reporting of non-targeted species for specific surveys.
- The Fishes of Minnesota Mapper does not document a fish species that I know exists in my neighborhood lake. Why not?
Absence of a species in the Fishes of Minnesota Mapper does not mean that the species doesn't occur in the lake, only that it wasn't observed in the surveys performed. Conversely, recording of a species during a particular historical survey doesn't mean that the species still exists in that lake today.
Lake surveys are often performed for very specific purposes and thus may over-represent or under-represent the numbers/sizes/proportions of species actually present due to the use of particular gears, habitat locations, times of year, and survey methods.
- Why are the locations of rare and sensitive species not shown (or are "obscured") in the Fishes of Minnesota Mapper?
Species whose populations are vulnerable to extinction may be given special protective status by federal or state governments. The locations of protected fish species are removed or "obscured" within the Fishes of Minnesota Mapper to protect them from being targeted by anglers and collectors, and to protect the vulnerable habitats in which they are found.
See Fishes of MN Mapper: Species Protection Status for lists of protected species and info about how these records are handled in the mapping application.
- When I change the Filter Tab criteria or turn data layers ON or OFF in the Map Tab, the Fishes of Minnesota Mapper display does not update the results.
The map display should update when you make any change in the data layers or Filter criteria. If not, first use reset to clear the filter criteria before selecting new criteria.
Make sure that there are Matching Records listed on the Filters Tab screen.
- If Matching Records = 0:
- use the reset link to reset the filter criteria before selecting new criteria
- check to make sure that your filter query makes sense
- there just may not be any records matching your criteria
- If Matching Records > 100,000:
- this is too many points to display on the map
- reduce the number of records through additional filtering and/or zooming in
- If Matching Records = 0:
- What web browser do I need to use the Fishes of Minnesota Mapper?
Note: There is a known issue when navigating between the Tabular Results window and the Map Display when using Internet Explorer. (See How to Use: Troubleshooting for more info.)
Please report additional problems to the email address below.
- Reference Websites
MN DNR Sites
- Fishes of MN - species lists, descriptions and photos for MN fish species
- LakeFinder - recent written survey for surveyed lakes
- Rare Species Guide- species lists, descriptions and photos for MN rare species
Fish Mapping and ID Sites
- Fishes of Canada
- Fishes of MN Species Checklist - species natural history
- NatureServe Explorer
- Ontario MNR Fish ID
- USGS Fisheries Database Browser
- Wisconsin DNR: Where to fish
- Fish ID
Books and Articles
For questions regarding the Fishes of Minnesota Mapper data or to report problems with this web application, please contact [email protected]