Presentation on theme: "Sturbridge Great Ponds 2010 Annual Monitoring Report Presented by: David Mitchell Sponsored by: Sturbridge Conservation Commission and Sturbridge Lakes."— Presentation transcript:
Sturbridge Great Ponds 2010 Annual Monitoring Report Presented by: David Mitchell Sponsored by: Sturbridge Conservation Commission and Sturbridge Lakes Advisory Committee Sturbridge Senior Center June 17, 2010
Tonight’s Presentation Introduction to Sturbridge Conservation Commission (SCC) Lake Monitoring Program Results from Summer 2009 Lake Sampling and Data Comparisons between Lakes Planning for 2010 Lake Monitoring Program Discussion of U.S. EPA 2010 National Lake Assessment Report Update on Sturbridge Lakes Advisory Committee (SLAC) activities
SCC Lakes and Ponds Inventory, Monitoring, and Management Strategy Conduct Annual Lake and Pond Monitoring Develop Sturbridge Lake and Pond Water Quality Database Watershed Delineation and Characterization Coordinate with Lake Associations to develop long-term Lake Management and Watershed Protection Plans (LM/WPPs) – QQLA (South Pond) has just developed a long-term LM plan
Great Ponds* of Sturbridge Currently Being Monitored Big Alum Pond Cedar Lake East Brimfield Reservoir/Long Pond Leadmine Pond South (Quacumquasit) Pond Walker Pond * Defined by MGL Chapter as ponds containing in their natural state more than ten acres of land, and subject to any rights in such ponds which have been granted by the Commonwealth.
Reasons for Lake Monitoring Provides baseline data to compare with future data to detect trends Forms basis for conducting informed lake management Allows evaluation of efficiency of various treatments Economic incentives for protection of lake real estate values
Lakes Monitoring Program Lakes sampled during mid-summer (July-Aug.) Central location (deep hole) and other location –Shallow (0.5 ft) and deep (2-3 ft off bottom) Thermal and dissolved oxygen (DO) profiles Secchi Disk Transparency (SDT) Water Quality Samples taken: –Nutrients - nitrogen and phosphorus fractions –Other - alkalinity, hardness, TSS, iron, conductivity –Biological – chlorophyll a, zooplankton
Sturbridge Great Ponds LakeSize (ac)Depth (ft) Watershed to Lake Area Ratio Origin Big Alum Pond :1 Natural with dam Cedar Lake :1 Natural with dam E. Brimfield Reservoir :1 Natural with dam Leadmine Pond :1 Natural South Pond :1 Natural Walker Pond :1 Natural with dam
Thermal and Dissolved Oxygen Profiles and SDT Measurement
How deep is your lake? Average lake depth is important –Influences light availability for aquatic weeds –Lakes with >15-20 ft will usually seasonally stratify Forms two layers with different temperature and water quality in summer –Algal blooms usually confined to upper layer –Bottom layer may provide coldwater fish habitat –Recycling of nutrients Is there a single water layer or a deeper colder layer where the big trout are lurking?... and even deeper?
Epilimnion Hypolimnion Thermocline
Epilimnion Hypolimnion Thermocline
Sturbridge Deep Lakes 2009 Temperature and DO Depth Profiles
Sturbridge Shallow Lakes 2009 Temperature and DO Depth Profiles
Water Quality Sampling
Big Alum Pond BA-2 BA-1
CL-1 CL-2 Cedar Lake
East Brimfield Reservoir / Long Pond Largest Great Pond in Sturbridge and last to be monitored Only shoreline-based monitoring in 2009 Initial water quality data indicates some influence of Route 20 EBR-2
Comparisons in Water Quality between Deep and Shallow Lakes: data Shallow Lakes –Max. depth = 16 ft –SDT = 6.1 ft (n=26) –Alkalinity = 10.3 mg/L (n=39) –Sp. Cond = 294 uS (n=50) –Sodium = 42.1mg/L (n=41) –Chloride = 71.8 mg/L (n=40) –Chl a = 8.7 ug/L (n=10) Deep Lakes –Max. depth = ft –SDT = 15.3 ft (n=48) –Alkalinity = 10.9 mg/L (n=58) –Sp. Cond = 94.0 uS (n=70) –Sodium = 7.6 mg/L (n=59) –Chloride = 15.3 mg/L (n=59) –Chl a = 5.75 ug/L (n=15)
Carlson’s Trophic State Indicators
Comparison of 2009 TSI scores for Sturbridge Lakes Mean Carlson TSI Scores Big Alum Pond = 36 Cedar Lake = 54 EBR/Long Pond = 49 Leadmine Pond = 42 South Pond = 38 Walker Pond = 47 Lake Chl a (ug/L) TP (ug/L) SDT (ft) Big Alum Pond NA815.7 Cedar Lake NA213.3 E. Brimfield ReservoirNA175.0 Leadmine Pond NA South Pond NA812 Walker Pond NA218.5
Trophic States of Sturbridge Lakes TSI Score & Trophic Classifications Oligotrophic = < 38 (poorly fertilized) Mesotrophic = (moderately fertilized) Eutrophic = (well fertilized) Hypereutrophic = > 66 (extremely fertilized) Sturbridge Lakes Big Alum: Oligotrophic Cedar Lake: Eutrophic EBR/Long Pond: Eutrophic Leadmine: Mesotrophic South: Oligo-Mesotrophic Walker: Mesotrophic
Comments on 2009 Monitoring Program Results (1) Lake water quality indicates generally good conditions, but some mixed signals –Water clarity values well within seasonal ranges previously recorded –Higher TP and DP observed this year Big Alum Pond good score, but productivity is showing up in oxygen deficits at bottom Cedar Lake is challenged by low water clarity and high nutrient levels East Brimfield Reservoir – appears to eutrophic, which is consistent with its weedy conditions
Comments on 2009 Monitoring Program Results (2) Leadmine Pond appears to be trending to slightly lower SDT, still the most weed-free South Pond has variable record, probably due to North Pond influences; last year was good. Walker Pond had good year, high TP near north end noted Overall, results are well within the variability seen in the last 7 years.
Common and non-native invasive aquatic macrophytes in Sturbridge Lakes Common species : Chara / Nitella Elodea canadensis Myriophyllum heterophyllum Najas flexilis Potomogeton (10 species) Utricularia Vallisneria americana Non-indigenous invasive species : Cabomba caroliniana (South Pond) Myriophyllum spicatum (South Pond) Potomogeton crispus (Big Alum Pond, Cedar Lake)
Thanks to All the 2009 Lake Monitoring Volunteers SCC – Dave Mitchell, Erin Jacques, Matt Mitchell, Peter Logan Big Alum Pond – Bruce Gran Cedar Lake – Pat Wondolewski Leadmine Lake – Laurel and Steve Carpenter South Pond – Marita and Jeff Tasse Walker Pond – Doug Smith
Sturbridge Lakes Monitoring 2010 SCC Lake Monitoring –We will conduct another round of physiochemical measurements and WQ sampling. –Sampling tentatively scheduled for Friday-Saturday in August –Exact schedule of lake sampling to be finalized in July Many thanks to those who have already given generously of their time to make these events happen and the monitoring successful. Volunteers and boats are always appreciated !
National Lakes Assessment The National Lakes Assessment (NLA) is the first-ever baseline study of the condition of the nation’s lakes and results were recently reported by USEPA (2010). The NLA provided unbiased estimates of the condition of natural and man-made freshwater lakes, ponds, and reservoirs >10 acres and at least one meter deep. –Using a statistical survey design, lakes were selected at random to represent the condition of the larger population of lakes across the lower 48 states. –A total of 1,028 lakes were sampled for the NLA during summer 2007, representing the condition of about 50,000 lakes nationwide. The NLA finds that 56% of the nation’s lakes support healthy biological communities when compared to least disturbed sites; with 21% “fair” and 22% judged “poor”
This rating is based on an index of phytoplankton and zooplankton taxa loss – the percentage of taxa observed compared to those that are expected, based on conditions at least-disturbed lakes U.S. EPA, 2010
What are the stress factors for lakes ? Water Quality and Chemistry –Total Phosphorus –Total Nitrogen –Dissolved Oxygen –Turbidity Aquatic Habitat –Lake Shoreline Disturbance –Lake Shoreline Habitat –Shallow Water Habitat –Physical Habitat Complexity
Extent and Risk of Stressors U.S.EPA, 2010
It is not just nutrients ! Large amount of risk associated with poor habitat conditions – lakeshore and shallow water –Lakeshore habitat is rated poor in 36% of lakes. –Poor biological health is three times more likely in lakes with poor lakeshore habitat relative to lakes with good habitat. The nutrients nitrogen and phosphorus are at high levels in about twenty percent of lakes. –Poor biological health is 2.5 times more likely in lakes with high nutrient levels.
National Trends – Somewhat encouraging A comparison of NLA data to a subset of wastewater- impacted lakes sampled 35 years ago suggests that the nation’s investments in wastewater treatment and other pollution control activities are working despite increased population pressures across the United States. The report finds that nearly 75% of the 800 lakes sampled in the 1970s showed either improvements or no change in phosphorus levels. Trophic status also improved or remained the same in about 75% of those lakes.
Take-home messages for Sturbridge Shoreline Residents Healthy lakes often have “messy” shorelines with lots of natural vegetation Lake shallows “cleanups” during drawdown do not promote a better lake Try to limit your shoreline “footprint” as much as possible For more information or to get a copy of the National Lakes Assessment, visit
Sturbridge Lakes Advisory Committee (SLAC) Background Established by Sturbridge Board of Selectmen in Dec to get lake associations from five Great Ponds together to identify common concerns and issues and provide recommendations to Selectmen; SLAC met between March and July 2008, summary Final Report and recommendations presented to Town and discussed with Selectmen in January 2009; SLAC officially recognized by Town through passage of warrant article at June 8 th 2009 Town Meeting; and SLAC representatives appointed in spring 2009 and have been meeting to identify and recommend action items.
List of SLAC Lake Representatives Town of Sturbridge Selectmen – Teddy Goodwin; Sturbridge Conservation Commission - Donna Grehl; Big Alum Lake Association – Joel Casaubon, Tammy Chase (Secretary), Bruce Gran; Cedar Lake Association – Greg Abrams, Fran O’Connell; United States Army Corps of Engineers (USACE) - Tom Chamberland (for East Brimfield Reservoir / Long Pond); Leadmine Pond Association – Laurel/Steve Carpenter. Bill Kenyon (former), Laurie Palmer; Quaboag-Quacumquasit Lake Association (QQLA) – Chris Reidy, Marita Tasse, David Mitchell; and Walker Pond Association – Greg Hale, John O’Brien Jr.
Sturbridge Lakes Advisory Committee (SLAC) Mission Statement The mission of the Sturbridge Lake Advisory Committee is to establish wise stewardship and an effective management mechanism for the sustainable use of the Town’s water resources and protection of their watersheds. Lake management should be developed through consensus from a collaborative, community wide pool of stakeholders that shall include lake users, lake associations, civic groups, and municipal government.
Goals of the SLAC SLAC encourages wise use and enjoyment of our Great Ponds coupled with environmentally- sound stewardship of these common resources; SLAC looks to create and enhance public awareness within Sturbridge, of the lakes, their range of resources and their overall value to the community; and SLAC will work to develop recommendations for the Board of Selectmen to better protect and preserve these important natural resources.
Common Concerns and Issues SLAC has identified several concerns or issues generally recognized to be relevant for some or all of the Sturbridge Lakes surveyed. SLAC Sub Committees have been formed to address these concerns or issues: –Boating Regulations, –Aquatic Plant Management, –Water Quality, –Community Outreach, –Legislative, –Communications, and –Funding.
Continuing Activities for SLAC (1) Gather useful information and best management practices from diverse sources: State, internet, literature, other lake associations, etc. –Recent presentation on organization and funding by Dick Cazeault, WLA president Sub-Committee members will continue to meet to provide solutions for issues that can be shared and implemented by all Coordinate activities with Town agencies and keep Selectmen informed of progress
Continuing Activities for SLAC (2) SLAC meetings held on last Wednesday of the month at the Sturbridge Senior Center –Look to recruit additional volunteers to work on the high priority issues; –Don’t need to be in a lake association to join! For additional information contact: –John O’Brien (SLAC president) at: –Selectman Teddy Goodwin at:
Photo credits Big Alum Pond aerial – Lycott website Cedar Lake – Pat Wondolewski East Brimfield Reservoir – USACE website Leadmine Lake – Bill Kenyon South Pond – Donna Grehl Walker Pond – John Hoffman
Big Alum Pond BA-1 (8/14/2009) Nutrients and Secchi Disk Depth
Cedar Lake (8/15/09) Nutrients and Secchi Disk Depth
East Brimfield Reservoir (8/14/09) Nutrients and Secchi Disk Depth
Leadmine Pond LP-1 (8/15/09) Nutrients and Secchi Disk Depth
South Pond SP-1 (8/14/09) Nutrients and Secchi Disk Depth
Walker Pond WP-2 (8/15/09) Nutrients and Secchi Disk Depth
Basic Principles For Lake Management Fresh water is a finite, fragile and valuable resource with profound biological complexity and intrinsic beauty. Water has an economic value in all its competing uses, and should be recognized as an essential good. Each lake has its own unique natural and manmade characteristics. Excessive utilization and degradation of lake resources will cause significant lake problems and reduce its value to the community. The wise and prudent use of water resources should contribute directly to sustainable socioeconomic development while preserving their natural aquatic and terrestrial ecosystems. The management of lakes for their sustainable use requires the resolution of conflicts among competing users of the lake resources, taking into account the needs of present and future generations and nature. Decision making for lake management should be based on sound science and the best available information. Good governance, based on fairness, transparency and empowerment of all stakeholders is essential.