Algae: Natural Indicators of Environmental Change

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

14

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

6

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