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
November 22, 2017 1 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
25.0 n=1994 20.0
15.0
10.0
5.0 Percent of lakes sampled lakes of Percent Canadian Shield 0.0 0-2 2-4 4-6 6-8 >30 8-10 10-12 12-14 14-16 16-18 18-20 20-22 22-24 24-26 26-28 28-30
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)
(Source: Lakeshore Capacity Assessment Handbook- May 2010) 4 Prices rise by ~6% for every metre increase in water clarity
5 Environmental stressors Acid deposition
Climate change Contaminants
Inland Lakes
Invasive species Emerging issues
Land-use Photo: Gregory Brand change
6 (Smol, 2008. Pollution of Lakes and Rivers) 7 CITIZEN SCIENCE
Adapted from: Smol, 2008. Pollution of Lakes and Rivers 8 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 province- wide, 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 Water clarity Calcium Chloride (TP) (since 2008) (since 2015)
• Important nutrient • Estimated using a • Essential element • There have been controlling the growth Secchi Disk that is required by increases in of algae in Ontario all living organisms chloride Lakes concentrations across the province due to road salt
12 Total Phosphorus
13 Total Phosphorus
Algal abundance These water quality parameters: (phytoplankton, Chl-a) - are difficult or expensive to measure Transparency (Secchi disc depth) - cannot be managed directly Hypolimnetic dissolved O2
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 -1 3.5 deposition (acid rain) and biomass loss through timber 3.0 harvesting 2.5
• Recent laboratory and field experiments have shown that 2.0 when Ca levels fall below 1.5-2 mg/L, aquatic organisms may be 1.5 negatively affected
CalciumConcentration (mg·L • The LPP has been monitoring 1.0 Ca since 2008 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] 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 • Most lakes show no significant change in Secchi from 2000- 60 2014 50
40 • ~21% of the lakes show a decline in water clarity over 30 Lakes (%) Lakes time
20
10 • This could be due to long-term increases in dissolved organic 0 carbon (DOC) – lakes are No change Strong Weak Weak Strong becoming more tea-stained in decline decline increase increase appearance Long-term trend in Secchi transparency
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 29 Other resources
• Data mapping tool (www.ontario.ca/environment-and- energy/map-lake-partner)
• Data (www.ontario.ca/data/ontario-lake- partner)
• Dorset Environmental Science Centre (www.desc.ca)
• Federation of Ontario Cottagers’ Associations (www.foca.on.ca)
• Toll-free Hotline: 1-800-470-8322; email: [email protected]
• Spills Action Centre (if you suspect a blue-green algal bloom): 1-800-268-6060
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