Volunteer Water Monitoring

We support and coordinate volunteer water monitoring in conjunction with BCLARA, TRWA, and individual lake and watershed associations.

Our goal is to compile and maintain a comprehensive baseline dataset on at least 100 lakes in Beltrami County.

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  • Overview
  • BCLARA
  • TRWA
  • Clean Water Legacy
  • Carlson TSI
  • Ecoregions
  • Related Resources

Beltrami SWCD is involved in many aspects of water quality.   With the aid of citizen volunteers, we sample numerous lakes around the county every year to establish Carlson TSI rankings to track nutrient changes over time. Parameters sampled include chlorophyll-a, total phosphorus, secchi, dissolved oxygen, temperature and conductivity. We focus on total phosphorus because it is the critical limiting nutrient in most of our lakes.

Lakes are chosen for a variety of reasons including  date last sampled, whether there is a boat access and development pressure.  If you live on a lake that does not have access, and you would be willing to help us sample once a month for May-September, please contact our office and we will put it on our list for consideration.  Typical sampling events take anywhere from 15 minutes to an hour depending on lake depth, weather, and distance to sampling location.  For consistency, samples are taken at the deepest part of the lake.

Beltrami County Lakes and Rivers Association (BCLARA)

BCLARA member associations include: Lake Andrusia Watershed Association, Friends of Lake Bemidji, Big Bass Lake Association, Big Lake Association, Clearwater Lake Area Association, Grace Lake Watershed Association, Lake Julia Association, Long Lake Association, Plantagenet Lake Owners Association, South Lake Irving Association, Star Island Protective League, and the Stump Lake Association. In addition, all member lakes of the Turtle River Wateshed Association (see next tab) belong to BCLARA. Lakes participating in on-going water quality monitoring are marked with an asterisk.

Turtle River Watershed Association

The Turtle River Watershed Association includes the following lakes: Beltrami, Big Turtle, Black, Campbell, Deer, Fox, Little Turtle, Long (west), Movil, Three Island, and Turtle River Lake. Those participating in on-going water quality monitoring are marked with an asterisk.

2008 Sampling Dates: flyer listing sampling dates for 36 lakes in current grant-funded monitoring program

Carlson's Trophic State Index (TSI)

Robert Carlson (1977) developed this index was based on observed relationships of the seasonal means of Secchi disk transparency, chlorophyll a, and total phosphorus. The "greener" the lake the higher the TSI number, and the lower the water visibility. The index spans a 100 point scale and each increase of ten units corresponds to a doubling of algal biomass. A decrease in the TSI measurements of the same lake over time would indicate increasing water quality.

TSI parameters

  • Total phosphorus - this is the nutrient that usually determines how much aquatic plant and algal growth there will be in a lake.
  • Chlorophyll a - this is the chemical that makes plants and algae green. The amount of chlorophyll a in a lake is a measure of how much algae is in the water.
  • Secchi Disk - This is a measure of the transparency or of how "clear" the water is.

Lake Classification

  • Oligotrophic lakes have low nutrient levels, are usually deep, and have high oxygen levels in the bottom waters. These lakes have very few algal blooms. TSI values range from 0 to 40.
  • Mesotrophic lakes are in the "middle" of the trophic scale. They have increasing amounts of nutrients and slightly lower amounts of dissolved oxygen. There are temporary algae and aquatic plant problems. TSI values range from 41-50.
  • Eutrophic lakes are nutrient rich. They are usually shallow, "green" lakes that have limited oxygen levels in the bottom waters. They have persistent algae and aquatic plant problems. TSI values range from 51-70.
  • Hypereutrophic lakes are very green and have little or no oxygen in the bottom layers. There are extreme algae and aquatic plant problems. TSI range is >70.

Minnesota Ecoregions

Ecoregion Map

A comparison of trophic state indices and values from the various ecoregions of Minnesota . NLF = Northern Lakes and Forests ecoregion; NCHF = North Central Hardwood Forest; WCBP  = Western Corn Belt Plains; NGP = Northern Glaciated Plains.   (O=oligotrophic, M = mesotrophic, E = eutrophic).  Ecoregion values from Minnesota Pollution Control Agency.  The Typical values are the range from the 25th  to the 75th percentile for that Ecoregion. 
TP (ug/L) Chl-a (ug/L) Secchi (meters) Carlson TSI
TROPHIC STATUS O M E O M E O M E O M E
Stand. Crit ** <11 11-24 >24 <3.0 3.0-7.0 >7.0 >4.0 2.2-4.0 <2.2 <35 40-50 >55

NLF 		14-27 <10 2.4-4.6 41-52
NCHF 23-50 5-22     .......
1.5-3.2 		49-66
WCP

65-150

30-80

0.5-1.0 67-77

NGP 		130-250 30-55 0.3-1.0 67-73
 

The standard criteria represent median values  calculated from six review papers from the published scientific literature (details in Axler, R., C. Rose, and C. Tikkanen. 1991.  An assessment of phytoplankton nutrient deficiency in N. Minnesota acid-sensitive lakes. Technical. Report  NRRI/TR-91/18.  114 p; submitted to Minnesota Pollution Control Agency Air Quality Division); Axler, R.P., C.Rose and C. Tikkanen. 1994.  Phytoplankton nutrient deficiency as related to atmospheric nitrogen deposition in northern Minnesota acid-sensitive lakes. Canadian Journal of Fisheries and Aquatic Sciences. 51:281-1296.

Beltrami SWCD resources

RMB Environmental Laboratory resources

Additional tools and resources