Burnt Shanty Lake ITASCA COUNTY

Transcription

1 Burnt Shanty Lake ITASCA COUNTY Lake Water Quality Summary Burnt Shanty Lake is located 23 miles north of Grand Rapids, MN in Itasca County. It is a small lake covering 198 acres (Table 1). Burnt Shanty Lake has no inlets or outlets, which classify it as a groundwater drainage lake. In lakes without outlets, the water levels can fluctuate depending on precipitation and the water table. Water quality data have been collected on Burnt Shanty Lake since 1985 (Tables 2 & 3). These data show that the lake is mesotrophc (TSI = 41) with clear water conditions most of the summer and excellent recreational opportunities. Table 1. Burnt Shanty Lake location and key physical characteristics. Location Data MN Lake ID: County: Ecoregion: Major Drainage Basin: Itasca Northern Lakes and Forests Mississippi R. Grand Rapids Latitude/Longitude: / Invasive Species: None ( as of 214) Physical Characteristics Surface area (acres): 198 Littoral area (acres): 127 % Littoral area: 64 Max depth (ft), (m): 33., 1.1 Inlets: Outlets: Public Accesses: 1 Table 2. Availability of primary data types for Burnt Shanty Lake. Data Availability Transparency data Good data set from Chemical data Only exists from the 198s. Inlet/Outlet data -- Not necessary. Recommendations For recommendations refer to page 19. RMB Environmental Laboratories, Inc. 1 of Burnt Shanty Lake

2 Lake Map Figure 1. Map of Burnt Shanty Lake with 21 aerial imagery and illustrations of, sample site locations, inlets and outlets, and public access points. Table 3. Monitoring programs and associated monitoring sites. Monitoring programs include the Citizen Lake Monitoring Program (CLMP), and MPCA Lake Monitoring Program Project (LMPP). Lake Site Depth (ft) Monitoring Programs LMPP: , CLMP: 1974, ; LMPP: ,1988 RMB Environmental Laboratories, Inc. 2 of Burnt Shanty Lake

3 Average Water Quality Statistics The information below describes available chemical data for Burnt Shanty Lake through 213 (Table 4). Data for total phosphorus, chlorophyll a, and Secchi depth are from the primary site 21. Minnesota is divided into 7 ecoregions based on land use, vegetation, precipitation and geology. The MPCA has developed a way to determine the "average range" of water quality expected for lakes in each ecoregion. For more information on ecoregions and expected water quality ranges, see page 11. Burnt Shanty Lake is in the Northern Lakes and Forests Ecoregion. Table 4. Water quality means compared to ecoregion ranges and impaired waters standard. Parameter Mean Ecoregion Range 1 Total phosphorus (ug/l) > 3 3 Chlorophyll a (ug/l) > 9 Chlorophyll a max (ug/l) 7. < 15 Secchi depth (ft) < 6.5 Impaired Waters Standard 2 Interpretation Results are better than the expected range for the Northern Lakes and Forests Ecoregion. Dissolved oxygen See page 8 Dissolved oxygen depth profiles show that the lake mixes in spring and fall. Total Kjeldahl Nitrogen (mg/l).5 <.4.75 Indicates insufficient nitrogen to support summer nitrogeninduced algae blooms. Alkalinity (mg/l) Indicates a moderate sensitivity to acid rain and a good buffering capacity. Color (Pt-Co Units) Indicates clear water with little to no tannins (brown stain). ph Within the expected range for the ecoregion. Lake water ph less than 6.5 can affect fish spawning and the solubility of metals in the water. Chloride (mg/l) Within the expected range for the ecoregion. Total Suspended Solids (mg/l) 1.5 <1 2 Indicates low suspended solids and clear water. Conductivity (umhos/cm) Within the expected range for the ecoregion. TN:TP Ratio :1-35:1 Within the expected range for the ecoregion, and shows the lake is phosphorus limited. 1 The ecoregion range is the 25 th -75 th percentile of summer means from ecoregion reference lakes 2 For further information regarding the Impaired Waters Assessment program, refer to 3 Chlorophyll a measurements have been corrected for pheophytin Units: 1 mg/l (ppm) = 1, ug/l (ppb) RMB Environmental Laboratories, Inc. 3 of Burnt Shanty Lake

4 Water Quality Characteristics - Historical Means and Ranges Table 5. Water quality means and ranges for primary sites. Parameters Primary Site 21 Site 12 Total Phosphorus Mean (ug/l): Total Phosphorus Min: Total Phosphorus Max: Number of Observations: 9 7 Chlorophyll a Mean (ug/l): Chlorophyll-a Min: Chlorophyll-a Max: Number of Observations: 9 6 Secchi Depth Mean (ft): Secchi Depth Min: Secchi Depth Max: Number of Observations: Figure Figure 2. Burnt 2. Lake Shanty insert Lake total total phosphorus, phosphorus, chlorophyll chlorophyll a and a and transparency transparency historical historical ranges. ranges. The The arrow arrow represents represents the the range range and and the the black black dot dot represents represents the the historical historical mean mean (Primary (Primary Site Site xxx). 21). Figure Figure adapted after Moore and Thornton, [Ed.] Lake and Reservoir Restoration Guidance Manual. (Doc. No. EPA 44/5-88-2) adapted after Moore and Thornton, [Ed.] Lake and Reservoir Restoration Guidance Manual. (Doc. No. EPA 44/ ) RMB Environmental Laboratories, Inc. 4 of Burnt Shanty Lake

5 Secchi Depth (ft) Precipitation (in) Transparency (Secchi Depth) Transparency is how easily light can pass through a substance. In lakes it is how deep sunlight penetrates through the water. Plants and algae need sunlight to grow, so they are only able to grow in areas of lakes where the sun penetrates. Water transparency depends on the amount of particles in the water. An increase in particulates results in a decrease in transparency. The transparency varies year to year due to changes in weather, precipitation, lake use, flooding, temperature, lake levels, etc. The annual mean transparency in Burnt Shanty Lake ranges from 12.8 to 19.5 feet (Figure 3). The annual means hover fairly close to the long-term mean. For trend analysis, see page 1. Transparency monitoring should be continued annually at site 21 in order to track water quality changes. 25 Precipitation Transparency and Precipitation 1 2 Secchi Mean Date Figure 3. Annual mean transparency compared to long-term mean transparency. Burnt Shanty Lake transparency ranges from 9. to 27.5 ft at the primary site (21). Figure 4 shows the seasonal transparency dynamics. The maximum Secchi reading is usually obtained in early summer. Burnt Shanty Lake transparency is high in May and June, and then declines through August. This transparency dynamic is typical of a Minnesota lake. The dynamics have to do with algae and zooplankton population dynamics, and lake turnover. It is important for lake residents to understand the seasonal transparency dynamics in their lake so that they are not worried about why their transparency is lower in August than it is in June. It is typical for a lake to vary in transparency throughout the summer. RMB Environmental Laboratories, Inc. 5 of Burnt Shanty Lake

6 Secchi Depth (ft) Seasonal Transparency Dynamics Grand Total Poly. (Grand Total) Figure 4. Seasonal transparency dynamics and year to year comparison (Primary Site 21). The black line represents the pattern in the data. User Perceptions When volunteers collect Secchi depth readings, they record their perceptions of the water based on the physical appearance and the recreational suitability. These perceptions can be compared to water quality parameters to see how the lake "user" would experience the lake at that time. Looking at transparency data, as the Secchi depth decreases the perception of the lake's physical appearance rating decreases. Burnt Shanty Lake was rated as being "crystal clear" 94% of the time by samplers at site 21 between 1988 and 214 (Figure 5). 6% Physical Appearance Rating 94% Crystal clear water 6% Not quite crystal clear a little algae visible % Definite algae green, yellow, or brown color apparent % High algae levels with limited clarity and/or mild odor apparent % Severely high algae levels 94% Figure 5. Burnt Shanty Lake physical appearance ratings by samplers. RMB Environmental Laboratories, Inc. 6 of Burnt Shanty Lake

7 Tptal Phosphorus (ug/l) As the Secchi depth decreases, the perception of recreational suitability of the lake decreases. Burnt Shanty Lake was rated as being "beautiful" 1% of the time from 1988 to 214 (Figure 6). Recreational Suitability Rating 1% Beautiful, could not be better % Very minor aesthetic problems; excellent for swimming, boating % Swimming and aesthetic enjoyment of the lake slightly impaired because of algae levels % Desire to swim and level of enjoyment of the lake substantially reduced because of algae levels 1% % Swimming and aesthetic enjoyment of the lake nearly impossible because of algae levels Figure 6. Recreational suitability rating, as rated by the volunteer monitor. Total Phosphorus Burnt Shanty Lake is phosphorus limited, which means that algae and aquatic plant growth is dependent upon available phosphorus. Total phosphorus was evaluated in Burnt Shanty Lake in , There are not enough data points to determine if there are any seasonal patterns in phosphorus concentration for the lake. The majority of the data points fall into the mesotrophic range (Figure 7) Eutrophic Mesotrophic Oligotrophic Total Phosphorus Figure 7. Historical total phosphorus concentrations (ug/l) for Burnt Shanty Lake site Phosphorus should be monitored again this decade since it hasn t been monitored since the 198s. RMB Environmental Laboratories, Inc. 7 of Burnt Shanty Lake

8 Chlorophyll a (ul/l) Chlorophyll a Chlorophyll a is the pigment that makes plants and algae green. Chlorophyll a is tested in lakes to determine the algae concentration or how "green" the water is. Chlorophyll a concentrations greater than 1 ug/l are perceived as a mild algae bloom, while concentrations greater than 2 ug/l are perceived as a nuisance Chlorophyll a Chlorophyll a was evaluated in Burnt Shanty Lake at site 21 in , 1988 (Figure 8). Chlorophyll a concentrations remained below 1 ug/l in all three years, indicating no algae blooms. Dissolved Oxygen Minor Algae Figure 8. Chlorophyll a concentrations (ug/l) for Burnt Shanty Lake at site 21. Depth (m) Dissolved Oxygen (mg/l) Dissolved Oxygen (DO) is the amount of oxygen dissolved in lake water. Oxygen is necessary for all living organisms to survive except for some bacteria. Living organisms breathe in oxygen that is dissolved in the water. Dissolved oxygen levels of <5 mg/l are typically avoided by game fisheries. Burnt Shanty Lake is a moderately deep lake, with a maximum depth of 33 feet. Dissolved oxygen profiles from data collected in 1988 show stratification developing midsummer (Figure 9). By September 21, 1988, the lake had turned over. In late summer, the thermocline was around 5 meters (16.5 feet), and the oxygen was depleted below that depth Figure 9. Dissolved oxygen profile for Burnt Shanty Lake. RMB Environmental Laboratories, Inc. 8 of Burnt Shanty Lake

9 Trophic State Index (TSI) TSI is a standard measure or means for calculating the trophic status or productivity of a lake. More specifically, it is the total weight of living algae (algae biomass) in a waterbody at a specific location and time. Three variables, chlorophyll a, Secchi depth, and total phosphorus, independently estimate algal biomass. Phosphorus (nutrients), chlorophyll a (algae concentration) and Secchi depth (transparency) are related. As phosphorus increases, there is more food available for algae, resulting in increased algal concentrations. When algal concentrations increase, the water becomes less transparent and the Secchi depth decreases. If all three TSI numbers are within a few points of each other, they are strongly related. If they are different, there are other dynamics influencing the lake s productivity, and TSI mean should not be reported for the lake. The mean TSI for Burnt Shanty Lake falls into the mesotrophic range (Figure 1). There is good agreement between the TSI for phosphorus and chlorophyll a, indicating that these variables are strongly related (Table 6). The TSI for transparency was lower, but this could be due to the fact that there is much more transparency data available than phosphorus and chlorophyll a data. Therefore, the Secchi TSI is likely the most representative of the lake. Mesotrophic lakes (TSI 4-5) are characterized by moderately clear water most of the summer. "Meso" Burnt Shanty Table 6. Trophic State Index for Burnt Shanty. Trophic State Index Site 21 TSI Total Phosphorus 45 TSI Chlorophyll-a 42 TSI Secchi 36 TSI Mean 41 Trophic State: Mesotrophic Numbers represent the mean TSI for each parameter. Hypereutrophic Eutrophic Mesotrophic Oligotrophic means middle or mid; therefore, mesotrophic means a medium amount of productivity. Mesotrophic lakes are commonly found in central Minnesota and have clear water with algal blooms in late summer (Table 7) Figure 1. Trophic state index chart with corresponding trophic status. Table 7. Trophic state index attributes and their corresponding fisheries and recreation characteristics. TSI Attributes Fisheries & Recreation <3 Oligotrophy: Clear water, oxygen throughout Trout fisheries dominate the year at the bottom of the lake, very deep cold water. 3-4 Bottom of shallower lakes may become anoxic (no oxygen). Trout fisheries in deep lakes only. Walleye, Cisco present. 4-5 Mesotrophy: Water moderately clear most of the summer. May be "greener" in late summer. No oxygen at the bottom of the lake results in loss of trout. Walleye may predominate. 5-6 Eutrophy: Algae and aquatic plant problems possible. "Green" water most of the year. Warm-water fisheries only. Bass may dominate. 6-7 Blue-green algae dominate, algal scums and aquatic plant problems. Dense algae and aquatic plants. Low water clarity may discourage swimming and boating. 7-8 Hypereutrophy: Dense algae and aquatic plants. Water is not suitable for recreation. Source: Carlson, R.E A trophic state index for lakes. Limnology and Oceanography. 22: RMB Environmental Laboratories, Inc. 9 of Burnt Shanty Lake

10 9/1/1999 5/15/2 7/1/2 9/18/2 5/28/21 8/6/21 5/26/22 7/11/22 9/17/22 6/27/23 8/13/23 6/23/24 9/9/24 6/21/25 9/7/25 6/21/26 8/16/26 7/5/27 9/22/27 7/31/28 6/3/29 8/19/29 6/14/21 8/26/21 7/6/211 6/28/212 9/1/212 7/4/213 8/27/213 9/3/214 7/9/214 Secchi Depth (ft) Trend Analysis For detecting trends, a minimum of 8-1 years of data with 4 or more readings per season are recommended. Minimum confidence accepted by the MPCA is 9%. This means that there is a 9% chance that the data are showing a true trend and a 1% chance that the trend is a random result of the data. Only short-term trends can be determined with just a few years of data, because there can be different wet years and dry years, water levels, weather, etc, that affect the water quality naturally. Burnt Shanty Lake had enough data to perform a trend analysis on transparency (Table 8). The data were analyzed using the Mann Kendall Trend Analysis. Table 8. Trend analysis for Burnt Shanty Lake. Lake Site Parameter Date Range Trend 21 Total Phosphorus , 1988 Insufficient data 21 Chlorophyll a , 1988 Insufficient data 21 Transparency No trend 3 Burnt Shanty Transparency Trend Figure 11. Transparency (feet) trend for site 21 from Burnt Shanty Lake shows no evidence of a transparency trend (Figure 11). This means the transparency is stable. Transparency monitoring should continue so that this trend can be tracked in future years. RMB Environmental Laboratories, Inc. 1 of Burnt Shanty Lake

11 Total Phosphorus (ug/l, ppb) Chlorophyll-a (ug/l, ppb) Secchi depth (ft) Ecoregion Comparisons Minnesota is divided into 7 ecoregions based on land use, vegetation, precipitation and geology (Figure 12). The MPCA has developed a way to determine the "average range" of water quality expected for lakes in each ecoregion. From , the MPCA evaluated the lake water quality for reference lakes. These reference lakes are not considered pristine, but are considered to have little human impact and therefore are representative of the typical lakes within the ecoregion. The "average range" refers to the 25 th - 75 th percentile range for data within each ecoregion. For the purpose of this graphical representation, the means of the reference lake data sets were used. Burnt Shanty Lake is in the Northern Lakes and Forest Ecoregion. The mean total phosphorus, chlorophyll a and transparency (Secchi depth) for Burnt Shanty Lake are within the ecoregion ranges (Figure 13). Figure 12. Minnesota Ecoregions increased algae crystal clear NLF Ecoregion Burnt Shanty NLF Ecoregion Burnt Shanty 3 NLF Ecoregion Burnt Shanty Figure 13. Burnt Shanty Lake ranges compared to Northern Lakes and Forest Ecoregion ranges. The Burnt Shanty Lake total phosphorus and chlorophyll a ranges are from 9 data points collected in May-September of , The Burnt Shanty Lake Secchi depth range is from 211 data points collected in May- September of RMB Environmental Laboratories, Inc. 11 of Burnt Shanty Lake

12 Lakeshed Data and Interpretations Lakeshed Understanding a lakeshed requires an understanding of basic hydrology. A watershed is defined as all land and water surface area that contribute excess water to a defined point. The MN DNR has delineated three basic scales of watersheds (from large to small): 1) basins, 2) major watersheds, and 3) minor watersheds. The Mississippi River-Grand Rapids Major Watershed is one of the watersheds that make up the Upper Mississippi River Basin, which drains south to the Gulf of Mexico (Figure 14). Burnt Shanty Lake is located in minor watershed 925 (Figure 15). Figure 14. Major Watershed. Figure 15. Minor Watershed 925. The MN DNR also has evaluated catchments for each individual lake with greater than 1 acres surface area. These lakesheds (catchments) are the building blocks for the larger scale watersheds. Burnt Shanty Lake falls within lakeshed 9251 (Figure 16). Though very useful for displaying the land and water that contribute directly to a lake, lakesheds are not always true watersheds because they may not show the water flowing into a lake from upstream streams or rivers. While some lakes Figure 16. Burnt Shanty Lake lakeshed (9251) with land ownership, lakes, wetlands, and rivers illustrated. RMB Environmental Laboratories, Inc. 12 of Burnt Shanty Lake

13 may have only one or two upstream lakesheds draining into them, others may be connected to a large number of lakesheds, reflecting a larger drainage area via stream or river networks. For further discussion of Burnt Shanty Lake s watershed, containing all the lakesheds upstream of the Burnt Shanty Lake lakeshed, see page 17. The data interpretation of the Burnt Shanty Lake lakeshed includes only the immediate lakeshed as this area is the land surface that flows directly into Burnt Shanty Lake. The lakeshed vitals table identifies where to focus organizational and management efforts for each lake (Table 9). Criteria were developed using limnological concepts to determine the effect to lake water quality. KEY Possibly detrimental to the lake Warrants attention Beneficial to the lake Table 9. Burnt Shanty Lake lakeshed vitals table. Lakeshed Vitals Rating Lake Area 182 acres descriptive Littoral Zone Area 127 acres descriptive Lake Max Depth 35 feet descriptive Lake Mean Depth NA NA Water Residence Time NA NA Miles of Stream descriptive Inlets Outlets Major Watershed 9 - Mississippi River-Grand Rapids descriptive Minor Watershed 925 descriptive Lakeshed 9251 descriptive Ecoregion Northern Lakes and Forests descriptive Total Lakeshed to Lake Area Ratio (total lakeshed includes lake area) 6:1 Standard Watershed to Lake Basin Ratio (standard watershed includes lake areas) 6:1 Wetland Coverage (NWI) 9.5% Aquatic Invasive Species Public Drainage Ditches Public Lake Accesses 1 None Miles of Shoreline 5.24 miles descriptive Shoreline Development Index 2.77 Public Land to Private Land Ratio 4.4:1 Development Classification Natural Environment Miles of Road 5.1 miles descriptive Municipalities in lakeshed Forestry Practices None None Feedlots Sewage Management Individual Waste Treatment Systems (septic systems and holding tanks) Lake Management Plan None Lake Vegetation Survey/Plan DNR, 2 RMB Environmental Laboratories, Inc. 13 of Burnt Shanty Lake

14 Land Cover / Land Use The activities that occur on the land within the lakeshed can greatly impact a lake. Land use planning helps ensure the use of land resources in an organized fashion so that the needs of the present and future generations can be best addressed. The basic purpose of land use planning is to ensure that each area of land will be used in a manner that provides maximum social benefits without degradation of the land resource. Changes in land use, and ultimately land cover, impact the hydrology of a lakeshed. Land cover is also directly related to the land s ability to absorb and store water rather than cause it to flow overland (gathering nutrients and sediment as it moves) towards the lowest point, typically the lake. Impervious intensity describes the land s inability to absorb water, the higher the % impervious intensity the more area that water cannot penetrate in to the soils. Monitoring the changes in land use can assist in future planning procedures to address the needs of future generations. Figure 17. Burnt Shanty Lake lakeshed (9251) land cover (NLCD 211). Phosphorus export, which is the main cause of lake eutrophication, depends on the type of land cover occurring in the lakeshed. Figure 17 depicts the land cover in Burnt Shanty Lake s lakeshed. The National Land Cover Dataset (NLCD) has records from 21 and 211. Table 1 describes Burnt Shanty Lake s lakeshed land cover statistics and percent change from 21 to 211. Overall, there was not much change over this decade or from (Tables 1-11). RMB Environmental Laboratories, Inc. 14 of Burnt Shanty Lake

15 Percent Table 1. Burnt Shanty Lake s lakeshed land cover statistics and % change from 21 to 211 (Data Source: NLCD) % Change Land Cover Acres Percent Acres Percent 21 to 211 Deciduous Forest Developed, Open Space Emergent Herbaceous Wetlands Evergreen Forest Grassland/Herbaceous Mixed Forest Open Water Shrub/Scrub Woody Wetlands Total Area Table 11. Burnt Shanty Lake development area and % change from (Data Source: UMN Landsat) % Change Category Acres Percent Acres Percent 199 to 2 Total Impervious Area Urban Acreage Demographics Burnt Shanty Lake is classified as a Natural Environment lake. Natural Environment lakes usually have less than 15 total acres, less than 6 acres per mile of shoreline, and less than three dwellings per mile of shoreline. They may have some winter kill of fish; may have shallow, swampy shoreline; and are less than 15 feet deep. The Minnesota Department of Administration Geographic and Demographic Analysis Division extrapolated future population in 5-year increments out to 235. Compared to Itasca County as a whole, Balsam Township has a lower growth projection (Figure 18). Much of Balsam Township at Burnt Shanty Lake is public land; however, so it is protected by development. (source: 9% 8% 7% 6% 5% 4% 3% 2% 1% % Population Growth Projection Compared to 21 Population Balsam Township; 21 population = 577 Itasca County; 21 population = 45,58 Ec Dev Region; 21 population = 326, Year Figure 18. Population growth projection for adjacent townships and Itasca County. RMB Environmental Laboratories, Inc. 15 of Burnt Shanty Lake

16 Lakeshed Water Quality Protection Strategy Each lakeshed has a different makeup of public and private lands. Looking in more detail at the makeup of these lands can give insight on where to focus protection efforts. The protected lands (easements, wetlands, public land) are the future water quality infrastructure for the lake. Developed land and agriculture have the highest phosphorus runoff coefficients, so this land should be minimized for water quality protection. The majority of the land within Burnt Shanty Lake s lakeshed is publicly owned (Table 12). The majority of the privately owned land is forested. This land can be the focus of development and protection efforts in the lakeshed. Table 12. Land ownership, land use/land cover, estimated phosphorus loading, and ideas for protection and restoration in the lakeshed (Sources: County parcel data and the 211 National Land Cover Dataset). Private (15.5) 21.9 Public (62.6) Developed Agriculture Forested Uplands Other Wetlands Open Water County State Federal Land Use (%) Runoff Coefficient Lbs of phosphorus/acre/year Estimated Phosphorus Loading Acreage x runoff coefficient Description Focused on Shoreland Cropland Focus of development and protection efforts Open, pasture, grassland, shrubland Protected Potential Phase 3 Discussion Items Shoreline restoration Restore wetlands; CRP Forest stewardship planning, 3 rd party certification, SFIA, local woodland cooperatives Protected by Wetland Conservation Act County Tax Forfeit Lands State Forest National Forest DNR Fisheries approach for lake protection and restoration Credit: Peter Jacobson and Michael Duval, Minnesota DNR Fisheries In an effort to prioritize protection and restoration efforts of fishery lakes, the MN DNR has developed a ranking system by separating lakes into two categories, those needing protection and those needing restoration. Modeling by the DNR Fisheries Research Unit suggests that total phosphorus concentrations increase significantly over natural concentrations in lakes that have watershed with disturbance greater than 25%. Therefore, lakes with watersheds that have less than 25% disturbance need protection and lakes with more than 25% disturbance need restoration (Table 13). Watershed disturbance was defined as having urban, agricultural and mining land uses. Watershed protection is defined as publicly owned land or conservation easement. RMB Environmental Laboratories, Inc. 16 of Burnt Shanty Lake

17 Table 13. Suggested approaches for watershed protection and restoration of DNR-managed fish lakes in Minnesota. Watershed Disturbance (%) Watershed Protected (%) Management Type Comments > 75% Vigilance < 25% < 75% Protection 25-6% n/a Full Restoration > 6% n/a Partial Restoration Sufficiently protected -- Water quality supports healthy and diverse native fish communities. Keep public lands protected. Excellent candidates for protection -- Water quality can be maintained in a range that supports healthy and diverse native fish communities. Disturbed lands should be limited to less than 25%. Realistic chance for full restoration of water quality and improve quality of fish communities. Disturbed land percentage should be reduced and BMPs implemented. Restoration will be very expensive and probably will not achieve water quality conditions necessary to sustain healthy fish communities. Restoration opportunities must be critically evaluated to assure feasible positive outcomes. The next step was to prioritize lakes within each of these management categories. DNR Fisheries identified high value fishery lakes, such as cisco refuge lakes. Ciscos (Coregonus artedi) can be an early indicator of eutrophication in a lake because they require cold hypolimnetic temperatures and high dissolved oxygen levels. These watersheds with low disturbance and high value fishery lakes are excellent candidates for priority protection measures, especially those that are related to forestry and minimizing the effects of landscape disturbance. Forest stewardship planning, harvest coordination to reduce hydrology impacts and forest conservation easements are some potential tools that can protect these high value resources for the long term. Burnt Shanty Lake s lakeshed is classified with having 8% of the watershed protected and 3% of the watershed disturbed (Figure 19). Therefore, this lakeshed should have a vigilance focus. Goals for the lake should be to protect public land. Burnt Shanty Lake is a headwaters lakeshed, which means that no other lakesheds flow into it (Figure 2). Percent of the Watershed Protected % 1% 75% Burnt Shanty Lake (8.2%) Percent of the Watershed with Disturbed Land Cover % 25% 1% Burnt Shanty Lake (3%) Figure 19. Burnt Shanty Lake s lakeshed percentage of watershed protected and disturbed. Figure 2. Lakesheds that contribute water to the Burnt Shanty Lake lakeshed. Color-coded based on management focus (Table 13). RMB Environmental Laboratories, Inc. 17 of Burnt Shanty Lake

18 Status of the Fishery (DNR, as of 9/2/23) Burnt Shanty Lake is a 182-acre lake in Itasca County within the Mississippi River watershed. Burnt Shanty is located 2 miles north of Grand Rapids, MN. The lake has a maximum depth of 35 ft and 127 littoral acres. There is a public access on the south shore off Forest Road 351. The northern pike gill-net catch was 8.8/net, which was higher most other lakes in lake class 32. Catch rates in past assessments have varied from 8.6 to 15.7/net. Size structure was good with fish up to 31 inches sampled. Growth was similar to the statewide average with fish reaching 26 inches by age 8. The bluegill trap-net catch was 7.5/net, below the expected range for similar lakes. Catch rates in past assessments have varied from 5.5 to 28./net. Size structure was poor with no fish larger than 8 inches. Growth was faster than the lake class average with fish growing to 6 inches by age 6. The black crappie gill-net catch was 5.5/net, which was higher than the expected range for similar lakes. Catch rates in past assessments have varied from 4.7 to 9.5/net. The catch rate in trap nets was 1.3/net, which was within the expected range. Size structure for fish sampled in gill nets was poor with no fish exceeding 1 inches, although some fish up to 11 inches were sampled in trap nets. Growth was similar to the statewide average for ages 1 to 5 and below the average for ages 6 to 8. Fish reach 9 inches by age 8. Electrofishing was used for the first time to sample largemouth bass. The catch rate was 3.9/hour, which indicates a moderately abundant population. Size structure was moderate with a fish up to 19 inches sampled. Growth was similar to the statewide average with fish growing to 15 inches by age 7. Yellow bullhead catch rate declined to 48.2/net, however it is still much higher than the expected range. Catch rates in the two most recent assessments have been very high, varying from 92. to 98./net. The yellow perch catch rate was 1.2/gill net, which was within the expected range for similar lakes. Catch rates in past assessments have varied from to 1.2/net. Size structure was poor with no fish exceeding 7 inches. Two walleye were sampled in gill nets, which is the first time walleye have been sampled in Burnt Shanty. In order to maintain or improve fish and wildlife populations, water quality and habitat must be protected. People often associate water quality problems with large-scale agricultural, forestry, urban development or industrial practices in the watershed. In reality, the impact of land use decisions on one lake lot may be relatively small, yet, the cumulative impact of those decisions on many lake lots can result in a significant decline in water quality and habitat. For example, removing shoreline and aquatic vegetation, fertilizing lawns, mowing to the waters edge, installing beach sand blankets, failing septic systems and uncontrolled run-off, all contribute excess nutrients and sediment, which degrade water quality and habitat. Understanding these cumulative impacts and taking steps to avoid or minimize them will help to insure our quality fisheries can be enjoyed by future generations. See the link below for specific information on gillnet surveys, stocking information, and fish consumption guidelines. RMB Environmental Laboratories, Inc. 18 of Burnt Shanty Lake

19 Key Findings / Recommendations Monitoring Recommendations Transparency monitoring at site 21 should be continued annually. It is important to continue transparency monitoring weekly or at least bimonthly every year to enable year-to-year comparisons and trend analyses. Total Phosphorus and chlorophyll a should be monitored sometime this decade since it has not been monitored since the 198s. Overall Summary Burnt Shanty Lake is a mesotrophic lake (TSI = 41) with no evidence of a trend in water clarity. The total phosphorus, chlorophyll a and transparency ranges are within the ecoregion ranges. Only two percent (3%) of the Burnt Shanty Lake lakeshed is disturbed by development and agriculture (Figure 19). The threshold of disturbance where water quality tends to decline is 25%. Burnt Shanty Lake is well under this threshold. More than half (63%) of the lakeshed is publicly owned, which protects that land from development (Table 12). Burnt Shanty Lake is surrounded by the George Washington State Forest and Chippewa National Forest Burnt Shanty Lake has the advantage of a very small watershed. The lake does not have any major inlets, which means that it is probably groundwater fed. It is in a headwaters catchment, which means no other lakes flow into it. This means that the main potential impacts to the lake are land practices directly around the shoreline. Priority Impacts to the Lake All the non-public land around Burnt Shanty Lake has been developed in the first tier, and the second tier is protected by public land (Figure 16). The priority impact to Burnt Shanty Lake would be the expansion of residential housing development in the first tier. The conversion of small lake cabins to year-round family homes increases the impervious surface and runoff from the lake lots. Best Management Practices Recommendations The management focus for Burnt Shanty Lake should be to protect the current water quality and lakeshed. Efforts should be focused on managing and/or decreasing the impact caused by additional impervious surface area on existing lots (conversion of seasonal cabins to year-round homes). The current lakeshore homeowners can lessen their negative impact on water quality by installing or maintaining the existing trees on their properties. Forested uplands contribute significantly less phosphorus (lbs/acre/year) than developed land cover (Table 12). Forested uplands can be managed with Forest Stewardship Planning. In addition, filter strips or native vegetative buffers could be installed to decrease or slow the runoff reaching the water s edge. Septic systems should be pumped and inspected regularly. The lakeshed still has large undeveloped shoreline parcels (Figure 16). Because a lot of undeveloped private land still exists, there is a great potential for protecting this land with conservation easements and aquatic management areas (AMAs). Conservation easements can be set up easily and with little cost with help from organizations such as the Board of Soil and Water Resources and the Minnesota Land Trust. AMAs can be set up through the local DNR fisheries office. RMB Environmental Laboratories, Inc. 19 of Burnt Shanty Lake

20 Project Implementation The best management practices above can be implemented by a variety of entities. Some possibilities are listed below. Individual property owners Shoreline restoration Rain gardens Aquatic plant bed protection (only remove a small area for swimming) Conservation easements Forest stewardship planning Lake Associations Lake condition monitoring Ground truthing visual inspection upstream on stream inlets Watershed runoff mapping by a consultant Shoreline inventory study by a consultant Conservation easements Soil and Water Conservation District (SWCD) and Natural Resources Conservation Service (NRCS) Shoreline restoration Stream buffers Forest stewardship planning Wetland restoration Work with farmers to o Restore wetlands o Implement conservation farming practices o Land retirement programs such as Conservation Reserve Program Organizational contacts and reference sites Itasca County Environmental Services Department Itasca Soil and Water Conservation District DNR Fisheries Office Regional Minnesota Pollution Control Agency Office Regional Board of Soil and Water Resources Office 124 NE 4 th St., Grand Rapids, MN (218) East Highway 2, Grand Rapids, MN (218) East Highway 2, Grand Rapids, MN (218) Lake Avenue South, Duluth, MN 5582 (218) Minnesota Drive, Brainerd, MN 5641 (218) RMB Environmental Laboratories, Inc. 2 of Burnt Shanty Lake