Algae: Natural Indicators of Environmental Change Andrew Paterson Dorset Environmental Science Centre Ontario Min. of the Env. and Climate Change
Muskoka Stewardship Conference May 12th, 2017
(Photo: Kat RĂźhland)
But first…..some Algae 101 • • •
algae don’t belong to a single taxonomic group many algae aren’t “plants”
algae are considered to be a loose collection of organisms that share the following characteristics: photosynthesize aquatic
simple vegetative structures
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contain chlorophyll
no vascular system
•
algae come in many forms and sizes
Colonies
Unicells
8 orders of magnitude
6 orders of magnitude
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Filaments
•
algae exist anywhere there is moisture Cryptoendolithic algae
“Snow” algae
Nat. Geog. Oct. 1998
Courtesy J.P. Smol
Sheba the polar bear in Singapore 4
Algae are an essential part of aquatic ecosystems
Algae • • •
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are at (or near) the base of the food web convert nutrients to organic matter oxygenate the water
Algae as indicators of environmental change Example 1: Nearshore, attached
Example 2: Algae in lake
algae (periphyton) as indicators of watershed disturbance
sediments: Sensitive indicators of recent warming
Partnership with Mark MacDougall and Roland Hall (U Waterloo), and Jenny Winter and Chris Jones (MOECC) Mark MacDougall
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Kat Rühland
John Smol
Partnership with Kat Rühland and John Smol (Queen’s U); Branaavan Sivarajah’s MSc work
Diatoms • single-celled, microscopic algae that are made of “glass” • live in diverse habitats • distinct markings on cell walls can be used to differentiate species • sensitive to environmental change • respond rapidly to environmental change
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Periphytic algae: sensitive indicators of watershed disturbance? Algae that are attached to submerged surfaces in aquatic ecosystems
(Photo: Mark MacDougall)
(http://www.landcareresearch.co.nz/)
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ďƒ˜
commonly found in the nearshore regions of (deeper) lakes
ďƒ˜
attached to bedrock, cobbles, sediments, aquatic plants, (docks)
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Relative abundance (%)
Optimum
Tolerance
Environment (e.g., phosphorus levels)
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Relative abundance (%)
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Species 1
Species 2
8
6
4
2
0 0.9
1.0
1.1
1.2
Nutrients
1.3
1.4
1.5
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Relative abundance (%)
0.8
12 10 8 6 4 2 0 0.8
0.9
1.0
1.1
1.2
Nutrients
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1.3
1.4
1.5
Relative abundance (%)
sp. 4 sp. 1
sp. 3 sp. 6
sp. 2 sp. 5
Environment (e.g., phosphorus levels)
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Periphytic algae: sensitive indicators of watershed disturbances? Step 1: Select and sample lakes along a gradient of stress
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Periphytic algae: sensitive indicators of watershed disturbances? Step 1: Select and sample lakes along a gradient of stress 86 lakes sampled within the Muskoka River Watershed
Lower Stress
Proximity to roads % urban % agriculture Invasive species? Dams? etc.
Moderate Stress
Higher Stress 14
Periphytic algae: sensitive indicators of watershed disturbances? Step 2: Assess relationship between stress and algal community composition. Do we see different diatoms at different levels of stress?
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Periphytic algae: sensitive indicators of watershed disturbances? Step 2: Assess relationship between stress and algal
Diatom community composition
community composition. Do we see different diatoms at different levels of stress?
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3.5 3 2.5 2 1.5 1 0.5 0 0
1
2
3
4
5
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Increasing stress ďƒ (MacDougall et al. 2017)
Periphytic algae: sensitive indicators of watershed disturbances? Step 3: Build a regional index for assessing biological impairment in Muskoka
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Periphytic algae: sensitive indicators of watershed disturbances? Step 3: Build a regional index for assessing biological impairment in Muskoka
Index score
High quality
Low quality
Increasing stress 18
(MacDougall et al. in prep)
Example 2: Algae in lake sediments: indicators of recent warming
(Photo: Kat RĂźhland)
Lake sediments: archives of environmental change 19
Diatoms and warming: Size matters Smaller, lighter diatoms
Larger, heavier diatoms 20
5 Îźm
Diatoms and warming Strongly mixed water column / longer ice cover
(RĂźhland, Paterson, Smol, 2015)
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Diatoms and warming Strongly mixed water column / longer ice cover
Warming Weakly mixed / more stable water column
(RĂźhland, Paterson, Smol, 2015)
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Lake of the Woods in northwestern Ontario
Lake of the Woods
LANDSAT image
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Mean annual air temperature (°C)
Lake of the Woods in northwestern Ontario
Lake of the Woods
4.5 Air temperature - Kenora airport
4.0 3.5 3.0 2.5 2.0 1.5 1.0 1900
1920
1940
1960
1980
2000
2020
Year
(RĂźhland, Paterson, Smol, 2008)
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Lake of the Woods
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4.5 Air temperature - Kenora airport
4.0
% abundance of small, lighter diatoms
30 3.5 20
3.0 2.5
10
2.0 0
1.5 1.0 1900
1920
1940
1960
1980
2000
% abundance of Cyclotella species
Mean annual air temperature (°C)
Lake of the Woods in northwestern Ontario
2020
Year
Whitefish Bay, LOW (RĂźhland, Paterson, Smol, 2008)
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The Far North of Ontario Hudson Bay Lowlands
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The Far North of Ontario Hudson Bay Lowlands Temperature at Churchill, MB -4.5
-5.5 -6.0 -6.5 -7.0
2015
2010
2005
2000
1995
1990
1985
1980
1975
1970
1965
1960
1955
1950
1945
-7.5
Annual Temperature (°C)
-5.0
(Rühland et al. 2013)
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The Far North of Ontario Hudson Bay Lowlands Small, lighter diatoms Temperature at Churchill, MB -5.0
12 10
-5.5
8
-6.0
6
-6.5
4
-7.0
2 -7.5
Annual Temperature (°C)
Small, lighter diatoms (%)
-4.5 14
2015
2010
2005
2000
1995
1990
1985
1980
1975
1970
1965
1960
1955
1950
1945
0
North Raft Lake, HBL
(Rühland et al. 2013)
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Slow sinking diatoms (%)
Killarney Prov. Park
Mean Annual Temp (C)
Closer to home – Killarney Provincial Park
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George Lake
(Sivarajah et al. 2016)
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In closing…
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Many thanks to: Periphyton work:
Paleo work:
• Mark MacDougall, Dr. Roland Hall, Lillian Knopff (University of Waterloo)
• Dr. Kathleen Rühland, Dr. John Smol, Branaavan Sivarajah (Queen’s University)
• Dr. Jenny Winter (MOECC)
• DESC staff, past and present
• Dr. Cathy Eimers (Trent University) • Dorset Environmental Science Centre (DESC) staff, past and present •
Chris Jones (MOECC, Dorset)
• DESC students • Dr. Colin Yates and U. Waterloo students • Canadian Water Network
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•
Ron Ingram (MOECC, Dorset)
• DESC students • MOECC Best in Science Program, NSERC