This document discusses prioritizing restoration efforts in the Great Lakes. It provides an overview of the threats facing the lakes, including nonpoint runoff, toxics, invasives, and more. It describes a project called GLEAM that maps and assesses the relative magnitude of multiple stressors across the lakes. GLEAM developed weightings of each stressor's impact based on expert input. It then derives a cumulative stress map by summing the individual stressor maps weighted by their impact. The document argues this approach can help identify priority areas for Great Lakes restoration and conservation.

1. Prioritizing Great Lakes
Restoration
David Allan
The University of Michigan
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www.epa.gov/glnpo/image/
www.glfc.org/multimedia/photos.php#

2. Road Map
Road Map
• Threats to the Lakes: an overview
Threats to the Lakes: an overview
• Assessing the relative magnitude and
i h l i i d d
spatial distribution of multiple stressors –
Project GLEAM
P j GLEAM
• Prioritizing Great Lakes restoration and
conservation opportunities
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3. Threats to the Lakes: An Overview
Threats to the Lakes: An Overview
• Diverse
– Nonpoint runoff, toxics, invasives, development
• Changing in importance over time
Changing in importance over time
– May be diminishing, stable, or increasing
• Differ by location
– E.g., upper vs. lower lakes
• Multiple stressors are at work, and their
relative strength varies from place to place
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4. Environmental Stressors
Environmental Stressors
• An environmental stressor is a variable which, owing to
e o e a s esso s a a ab e c ,o g o
human activity, exceeds its range of normal variation,
affecting species, biological communities, or ecosystems
• The source of the stressor is the human activity causing
the stress
• Ecological indicators (biodiversity, ecosystem function)
help establish a stressor  response relationship

5. Categories of Stressors
Categories of Stressors
• Runoff from the land
Runoff from the land
• Toxic chemicals
• Fishing pressure
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• Invasive species
• Coastal development/Habitat loss
• Water withdrawal
Water withdrawal
• Climate change

6. Multiple Stressors
Multiple Stressors
• We’ve just seen seven broad categories of
We ve just seen seven broad categories of
stressors
– Each includes many specific stressors
Each includes many specific stressors
– Some are likely to be more important than others
– Few (any?) will be equal everywhere
Few (any?) will be equal everywhere
• How do we assess the cumulative influence
of multiple stressors across the Laurentian
of multiple stressors across the Laurentian
Great Lakes?

7. Project GLEAM: Mapping
Individual Stressors Across the
Great Lakes
Great Lakes
A AN, J. ., SMITH, S. .P., MCINTYR , P. ., HA P RN,
ALLAN, J.D., SMITH, S.D.P., MCINTYRE, P.B., HALPERN,
B., BOYER, G., BUCHSBAUM, A., BURTON, A.,
CAMPBELL, L., CHADDERTON, L., CIBOROWSKI, J.,
DORAN, P., EDER, T., INFANTE, D., JOHNSON, L.,
LODGE, D., READ, J., RUTHERFORD, E., SOWA, S.,
LODGE D READ J RUTHERFORD E SOWA S
STEINMAN, A., JOSEPH, C. And MARINO, A.

8. GLEAM Overview
GLEAM Overview
Great Lakes Environmental Assessment & Mapping
Great Lakes Environmental Assessment & Mapping
project
• Map the intensity of multiple stressors across the
Map the intensity of multiple stressors across the
Great Lakes (1‐km2 resolution)
• Develop weightings of relative impact of each
stressor by habitat type, based on expert judgment
• Derive a cumulative stress map summing all
individual stressors

9. Choice of Stressors
Choice of Stressors
Key stressor characteristics:
• Mappable at 1 km2 resolution
• Coverage for all 5 lakes
Co e age o a 5 a es
• Distinct pathway of impact from other stressors

10. Stressor Progress
CATEGORY STRESSOR CATEGORY STRESSOR
Hypoxia (low oxygen)
Hypoxia (low oxygen) Invasive zebra and quagga mussels
Invasive zebra and quagga mussels
Light pollution Ballast water invasion risk
Channel dredging Invasive sea lamprey
Shipping Lanes Emerging fish diseases (VHS, etc.)
Invasive and
Aquatic
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Industrial ports and harbors p ( g , )
Invasive wetland plants (Phragmites, etc.)
Nuisance
Habitat Tributary dams (altered flow/sediment retention Invasive nearshore plants (Eurasian milfoil, etc.)
Species
Alterations Tributary dams (barriers to fish passage) Harmful algal blooms (Microcystis, etc.)
Shoreline hardening Nuisance benthic algal blooms (Cladophora, etc.)
Shoreline extensions (docks, piers, etc.) Invasive plankton (Hemimysis, etc.)
Submerged cables and pipelines Invasive fish (round goby, etc.)
Marinas and recreational boating Nitrogen loading
Warming water temperatures Nonpoint Phosphorus loading
Climate
Decreasing ice cover Source Sediment loading (tributary)
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Change
Changing water levels
Ch i t l l Pollution
P ll ti Combined sewer overflows (CSOs)
C bi d fl (CSO )
Coastal road density Pharmaceutical loading
Coastal development (residential, commercial) Areas of Concern (AOCs)
Coastal
Coastal mining Toxic metals – biomagnifying (mercury, etc.)
Development
Coastal power plants
Coastal power plants Toxic Toxic pesticides (Atrazine, etc.)
Toxic pesticides (Atrazine etc )
Coastal recreational use (swimming, etc.) Chemical Toxic metals – non‐biomagnifying (copper, etc.)
Aquaculture Pollution Toxic organics – biomagnifying (PCBs, etc.)
Commercial fishing Toxic organics – non‐biomagnifying (PAHs, etc.)
Recreational fishing (charter) Emerging toxic chemicals (PBDEs, etc.)
Fisheries
Fisheries
Recreational fishing (non‐charter) Water Water withdrawals (inland and groundwater)
Management
Native fish stocking Withdrawals Water withdrawals (Great Lakes)
Non‐native fish stocking Not completed/not
Completed In progress
Diporeia decline feasible

11. Survey: Relative impact of stressors
We surveyed experts to weight individual stressors.
We want weightings that are:
‐ Stressor specific
‐ e.g., mercury is twice as harmful as nitrogen
‐ Habitat specific
‐ e.g., mercury in wetlands is twice as harmful as mercury in
open water
open water
‐ Quantitative
‐ “Ecosystem impact” is quantified for 5 criteria: temporal
frequency, spatial extent, ecological scope, magnitude of
change, recovery time
‐ Survey uses scenario comparisons to elicit how to combine
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these criteria for overall impact
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12. Cumulative Stress
‐ For each stressor, cumulative stress (CS) merges
‐ Intensity value for each pixel from stressor map (Si)
‐ Relative weight of each stressor from expert survey (Wi)
Relative weight of each stressor from expert survey
‐ Intensity and weight are normalized to 0‐1 range
‐ Sum across all stressors
CS = Sum (Si ∙ Wi)

13. GLRI Priority:
Working with
partners on
outreach
Prioritizing Restoration and
Conservation Opportunities
Some closing thoughts

14. Unique Challenges
Unique Challenges
• Scale
– The Great Lakes are large relative to most other
restoration targets
restoration targets
• Complexity
– The Great Lakes face a wider range of threats
relative to most other restoration targets
relative to most other restoration targets

15. Image courtesy
Michigan Sea Grant

16. The Value of Data
The Value of Data
Of the most important threats:
Of the most important threats:
– Which are most important? And where?
– How does the ranking of threats vary from
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nearshore to offshore, from the upper lakes to the
lower lakes?
– What is the cumulative influence of multiple
h h l fl f l l
threats?
• Where are our restoration priorities?
Where are our restoration priorities?
• Where are our conservation priorities

17. Guiding Principles
Guiding Principles
• Clarity of goals
Clarity of goals
– What do we want to achieve? What is feasible to
achieve? Who are we ?
achieve? Who are “we”?
• Best practices are identified, agreed upon and
followed
• Success is evaluated using metrics of
ecological condition
l i l diti
• The ecosystem is self‐sustaining

18. A Restoration Strategy
A Restoration Strategy
• Follow the Precautionary Principle – don’t allow
Follow the Precautionary Principle don t allow
restoration to become crisis management
• Prioritize risk identify the greatest threats
Prioritize risk – identify the greatest threats
• Place matters – recognize that the types and level of
threat varies with location
h i i hl i
• Networking is critical – rapid progress depends on
sharing of data, methods and ideas

19. With the help of many!
• Core Working Group
• Key team members
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– S. Smith, P. McIntyre, C. Joseph, A. Marino, A. Prusevich
– Students: R. Biel, J. Olson, K. Hanson
Students: R. Biel, J. Olson, K. Hanson
• Data providers
– Dozens of staff from GLERL, USGS, Environment Canada, OMNR,
USFWS, TNC, GLFC, MDNRE, IFR, GLEI, NFHAP
– Academic scientists from USA & Canada
Suggestions or Data to Share?
Suggestions or Data to Share?
sdpsmith AT umich.edu
dallan AT umich.edu
http://www.greatlakesmapping.org 19