Ontario s Cottage Country Lakes Long-term Trends in Water Quality from the Lake Partner Program Anna DeSellas and Andrew Paterson Dorset Environmental Science Centre, MOECC 1 November 22, 2017 Latornell Conservation Symposium
Inland lakes in Ontario 200,000+ lakes majority on Precambrian (Canadian) Shield soft-water, acidic, nutrient-poor water quality is generally good Percent of lakes sampled 25.0 20.0 15.0 10.0 5.0 n=1994 Canadian Shield 0.0 0-2 2-4 4-6 6-8 8-10 10-12 12-14 14-16 16-18 18-20 20-22 22-24 24-26 26-28 28-30 >30 Total Phosphorus (ug L -1 ) 2
Why is Water Quality Important to People? One of the most important concerns of waterfront property owners Makes for a more enjoyable lake experience swimming, boating, and other recreational activities 3
The economic value of clean water in Ontario ~2 million adult anglers per year $1.2 billion in fishing gear, boats, etc. $1.7 billion in activities related to fishing Photo: Gregory Brand $1 billion annually on recreational boating commercial fisheries (~$42.5 million) water-related tourism (~$5.5 billion) 4 (Source: Lakeshore Capacity Assessment Handbook- May 2010)
5 Prices rise by ~6% for every metre increase in water clarity
Environmental stressors Acid deposition Climate change Contaminants Inland Lakes Invasive species Emerging issues Land-use change Photo: Gregory Brand 6
(Smol, 2008. Pollution of Lakes and Rivers) 7
Adapted from: Smol, 2008. Pollution of Lakes and Rivers 8 CITIZEN SCIENCE
Lake Partner Program Mission: To foster interest and educate citizens on water quality issues affecting in inland lakes in Ontario To promote stewardship of lake ecosystem health in Ontario In partnership with Ontarians, to create and maintain a provincewide, long-term database on water quality for Ontario s inland lakes 9
Lake Partner Program Each year, > 600 volunteers monitor water quality and water clarity in 550 lakes at over 800 locations Volunteers send water samples to DESC chemistry lab for analyses Data are updated and shared annually online Data used to assess and report on water quality across Ontario Largest volunteer-based water quality monitoring program of its kind in Canada 10
An emphasis on Partner Through partnership, the LPP Collects more samples, more frequently at more locations across Ontario Enhances knowledge and education through stewardship The Federation of Ontario Cottagers Associations (FOCA) helps to recruit LPP volunteers, disseminates information, and trains and educates volunteers More effectively monitor & protect the health of Ontario s water resources 11
What we measure, and why Total Phosphorus (TP) Water clarity Calcium (since 2008) Chloride (since 2015) Important nutrient controlling the growth of algae in Ontario Lakes Estimated using a Secchi Disk Essential element that is required by all living organisms There have been increases in chloride concentrations across the province due to road salt 12
Total Phosphorus 13
Total Phosphorus Algal abundance (phytoplankton, Chl-a) Transparency (Secchi disc depth) These water quality parameters: - are difficult or expensive to measure - cannot be managed directly Hypolimnetic dissolved O 2 Total phosphorus [TP] the most reliable indicator of trophic status Photo: Kathryn Hargan 14
Total Phosphorus Current status In Ontario, the Provincial Water Quality Objective (PWQO) for total phosphorus in inland lakes is < 20 µg/l to: avoid nuisance concentrations of algae in lakes 15
Total Phosphorus Current status 93% of inland lakes in the Lake Partner Program meet the PWQO objective 16
Total Phosphorus Change over time? At a landscape scale, TP concentrations have not changed significantly over the last ~ten years 17
Calcium (Ca) Long-term declines in recent decades Ca levels have been declining in Ontario inland lakes Main causes are historical acid deposition (acid rain) and biomass loss through timber harvesting Recent laboratory and field experiments have shown that when Ca levels fall below 1.5-2 mg/l, aquatic organisms may be negatively affected The LPP has been monitoring Ca since 2008 Calcium Concentration (mg L -1 ) 3.5 3.0 2.5 2.0 1.5 1.0 1975 1980 1985 1990 1995 2000 Year 18
Ca is required by all living organisms Ca is a nutrient required by all living organisms to varying degrees some organisms are very sensitive to declining Ca levels e.g., Daphnia (zooplankton) - Ca is used to regenerate their carapaces when they moult 19
Calcium Current status The majority of LPP lakes in Ontario have Ca levels that can support calcium-rich aquatic organisms But, ~15% of lakes are at Ca concentrations that may hinder the reproduction and survival of some Ca-rich organisms (< 2.0 mg/l) 20
Calcium Change over time? Lakes are continuing to show declines in Ca concentrations (based on a comparison of 2008 and 2016 data from the LPP) 2016 [Ca] (mg/l) 2008 [Ca] (mg/l) 21
Water clarity measured using a Secchi Disk invented by Angelo Secchi in 1865, and modified for use in lakes by George C. Whipple in 1899 Secchi transparency depth is influenced by: - turbidity - algal biomass - colour of the water (influenced by dissolved organic matter) 22
Water clarity Current status 23
Water clarity Change over time (2000-2014)? 70 60 Most lakes show no significant change in Secchi from 2000-2014 Lakes (%) 50 40 30 ~21% of the lakes show a decline in water clarity over time 20 10 0 No change Strong decline Weak decline Weak increase Long-term trend in Secchi transparency Strong increase This could be due to long-term increases in dissolved organic carbon (DOC) lakes are becoming more tea-stained in appearance 24
Water clarity Change over time? 25
Water clarity Change over time? 26
Reporting on the data Recent (2016) survey of volunteers showed a desire to learn more about how the LPP data are used. Report Card - 2016 summary of current state of water quality (Ca, TP, Secchi) in 350-450 volunteer-monitored lakes across Ontario DESC student projects - 2016 (water clarity) & 2017 (calcium) Partnerships - 2016 project; Ryerson University, FOCA & MNRF; examined LPP phosphorus data & effects of landscape factors Story Map communicate the message and data www.desc.ca/programs/lpp 27
Acknowledgements This program would not be possible without the involvement of: the many Volunteers and Lake Stewards the Federation of Ontario Cottagers Associations (FOCA) MOECC Dorset Environmental Science Centre s water chemistry laboratory other DESC staff, including Partner staff The District Municipality of Muskoka Michelle Palmer, Claire Holeton, Kaoru Utsumi (MOECC Algae Lab) MOECC s Laboratory Services Branch & Operations Division 28
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Other resources Data mapping tool (www.ontario.ca/environment-andenergy/map-lake-partner) Data (www.ontario.ca/data/ontario-lakepartner) Dorset Environmental Science Centre (www.desc.ca) Federation of Ontario Cottagers Associations (www.foca.on.ca) Toll-free Hotline: 1-800-470-8322; email: lakepartner@ontario.ca Spills Action Centre (if you suspect a blue-green algal bloom): 1-800-268-6060 30