Many of our coastal wetlands have been permanently lost.  But how are we doing with protecting what we have?  Reporting the percentage of Great Lakes coastal wetlands that are protected can help focus efforts to preserve them where they are most needed.

This metric shows the percentage of wetlands protected at a glance, to highlight progress to-date and where we can do more.

What is the Current Status?

Overall, roughly 38% of remaining coastal wetlands* in the Great Lakes Basin are under protection of some sort.   However, this percentage varies significantly by location, even within smaller geographic areas.  This does not include the historical extent of wetlands in the Great Lakes, which has been significantly diminished.

*Coastal Wetlands defined as connected to the Great Lakes and >2 ha (5 acres) in size.

Percent of Great Lakes Coastal Wetlands protected by Great Lake. By Stephanie Hickel, The Nature Conservancy
<div class="text-formatted field field--name-field-media-tooltip field--type-text-long field--label-hidden field__item"><p>by Stephanie Hickel, The Nature Conservancy</p></div>


Figure 1. Percent of Coastal Wetlands that are protected, shown by Great Lake.  The total number of coastal wetland acres and the number of protected acres are shown for each lake.  This map provides a quick overview of lakewide status over the whole basin.



Percent of Great Lakes Coastal Wetlands protected, by state or province.  By Stephanie Hickel, The Nature Conservancy
<div class="text-formatted field field--name-field-media-tooltip field--type-text-long field--label-hidden field__item"><p>by Stephanie Hickel, The Nature Conservancy</p></div>


Figure 2. Percent of Coastal Wetlands that are protected for each state or province in the Great Lakes Basin (except Québec, due to data limitations).  The percentages vary from a high of 91% to a low of 4%, but the number of coastal wetland acres also varies widely.  The five states with the highest total wetland acreage have protected between 37% and 54% of coastal wetlands, while Ontario has protected 17%.



Percent protected of Great lakes coastal wetlands shown by sublake unit.  By Stephanie Hickel, The Nature Conservancy
<div class="text-formatted field field--name-field-media-tooltip field--type-text-long field--label-hidden field__item"><p>By Stephanie Hickel, The Nature Conservancy</p></div>


Figure 3. This map presents the percentage of existing wetlands that are in a protected status by sub-lake unit (reporting unit) for each Great Lake, as determined by the LAMPs for each lake. Lakes Michigan, Huron, Erie and Ontario report by sub-lake units. Lake Superior reports by watersheds.  All values for the number of wetlands, total acres, protected acres and percent protected by sub-lake unit are shown in Table 1.



Table 1. Data Values for all Sub-Lake Units. Can by sorted by Lake, Sub-Lake Unit, Number of wetlands, Total acres, Protected acres, and Percent Protected.

Sub-Lake Basin Data
Lake BasinSub-Lake BasinNumberTotal AcresProtected AcresPercent Protected
ErieHuron-Erie Corridor4540,7139,97625
ErieWestern Basin8130,75314,12346
ErieEastern Basin2620,7969,75847
ErieCentral Basin344,2813,55683
HuronGeorgian Bay17116,0092,14013
HuronOntario Southeastern Shores1099,5151,37314
HuronNorth Channel36840,2317,92120
HuronSaginaw Bay5754,86011,21320
HuronMichigan Western Shores10824,9148,26633
HuronMain Basin14829,91721,81773
MichiganSouthern Basin698,5792,77932
MichiganCentral Basin11635,24216,16746
MichiganGreen Bay16242,38122,83054
MichiganMid-lake Plateau2310,6436,03957
MichiganNorthern Basin15320,57112,90963
OntarioWestern Lake Ontario251,22000
OntarioEastern Lake Ontario45642,4226,47315
OntarioCentral Lake Ontario19521,0855,19125
SuperiorSt. Louis / Cloquet281,383463
SuperiorDog / Arrow152,11132515
SuperiorKeweenaw Peninsula / Sturgeon6321,2317,71336
SuperiorBlack Sturgeon41,36756541
SuperiorAgawa / Michipicoten-Magpie1301963
SuperiorJack Pine / Nipigon316410966
SuperiorWaiska / Tahquamenon186,4784,34567
SuperiorIsle Royale302,8182,818100
SuperiorBlack-Presque Isle / Ontonagon188100

How does this metric relate to our goal of diverse & resilient wetlands?

  • This metric can help to focus efforts on areas where conservation is most needed
  • The ability of wetlands to adapt (resiliency) is increased when they are protected from development or other permanent loss
  • The native biodiversity of wetland species requires enough wetland area to support their populations

What is our objective?

Objective: [Objectives for this metric are currently under development]

Metric: Percentage of Great Lakes coastal wetlands that are under protection measures.

This objective addresses our goal because...

Tracking the percentage of coastal wetlands in any given geographic unit illustrates most clearly where preservation and conservation efforts have been applied, and where ongoing efforts can be focused to improve the resiliency and diversity of remaining wetlands and benefit nearby coastal communities.

Further Details on this Goal

The Coastal Assembly's Goal 2 for Great Lakes Coastal Wetlands is to support diverse wetland types that are resilient and adaptable to changing conditions, [resulting in] a resilient system of Great Lakes coastal wetlands that is able to function within an extended range of variability, supports diversity of wetland types throughout the region, and adapts to changing climatic and hydrologic conditions.

Goal 2 was developed by the Coastal Assembly as the second of four high-level goals for Great Lakes coastal wetlands, and reflects the clear need to preserve coastal wetlands to the greatest extent possible, which will allow for the best potential for diversity and resiliency in the respective coastal ecosystems surrounding the Great lakes.  The Assembly envisions coastal landscapes that support the structure and natural processes essential for sustaining healthy species populations and resilient natural communities, and for providing benefits to human society.

This metric (percentage of coastal wetlands protected) provides a snapshot indicating past progress, current status, and areas for future improvement.  This supports Goal 2 by allowing wetland conservation efforts to be directed to areas where they are most critical for enhancing diversity and resiliency of wetland ecosystems.

Our visualization of this metric will help to aid policymakers as they look for ways to most efficiently direct policies and actions to support Great Lakes coastal communities.

We merged several protected land datasets (PAD-US, CARL, NCC and other sources) to create a best estimate of current protected wetlands.  We used protected lands from PAD-US that are in GAP Statuses 1-3.  We excluded GAP Status 4 because the protected status of some conservation easements is not always known.

Then, we intersected this dataset with the Great Lakes Coastal Wetland Consortium's 2004 wetlands, and dissolved these by wetland ID to ensure that acreages were not double-counted. 

Then, we calculated protected acreage on this merged dataset and joined this to the 2004 wetland polygons.  To calculate percentages, we divided the protected coastal wetland area in each geographic unit (State, Province, Lake, SubLake Unit) by the total coastal wetland area in that unit. 

Across the whole Basin:

The 38% figure represents the overall total for all coastal wetlands protected/total coastal wetlands.

By Great Lake:

  • Lake Superior, overall, shows the highest percent of protected coastal wetlands at 54%.  This is calculated from 38,438 acres protected/71,191 total acres. 
  • Lake Michigan is close behind Lake Superior, with 52%.  This was calculated from 60,723 protected acres/117,405 acres. 
  • Lake Erie came out with 39% protected.  This was calculated from 37,399/95,598 acres.
  • Lake Huron shows 30% protected, with the largest total acreage of wetlands.  This was calculated from 52,730 protected acres/175,458 acres.
  • Lake Ontario has the fewest, with 18% or 11,679 acres out of 65,673 total wetland acres.

By State/Province:

  • When the data are viewed by state, a wider variety of results emerges.  Pennsylvania has the highest percentage, but also a relatively low acreage (932 out of 1,025 acres).
  • Indiana has an even lower acreage of coastal wetlands, and reports 72% protected, or 504 out of 704 acres.
  • Illinois reports 54% protected, or 1,664 out of 3,099 acres.
  • Wisconsin comes in at 50% protected, with a large acreage (24,434 out of 49,004 acres).
  • Michigan has by far the largest acreage of coastal wetlands, and has 47% or 130,204 acres protected out of a whopping 275,887 acres.
  • Ohio has 45% of coastal wetlands protected, or 8,457 out of 18,667)
  • New York has 37% protected, or 9,791 out of 26, 402 acres.
  • Identifying a single number for the extent of Great Lakes coastal wetlands is a challenging endeavor.  We have chosen to use the Great Lakes Coastal Wetland Consortium data to get an estimate.  This estimate was calculated in 2004.
  • This can provide a snapshot of the potential for extending protection or restoration of coastal wetlands, with the knowledge that this estimate is based on several changing factors.
  • Definition of 'protected areas' can vary.  We chose to include lands that are in GAP Statuses 1 -3 for the U.S.  We used two Canadian databases that may have slightly differing definitions for protected areas.  This can be a source of variability.

We used the following database for coastal wetland area:


We used the following databases for protected area:


  • Nature Conservancy Canada (data agreement)





  • CARL (Conservation and Recreation Lands) 2017.  Feature Service for Conservation and Recreation Lands in the Great Lakes Atlantic Region (Wisconsin, Michigan, Ohio, Indiana, Iowa).  This layer contains fee lands, preserves, designated lands and other protected lands. This layer does not contain easements.


  • Consultations with regional land experts (The Nature Conservancy GIS Managers) for the states of Michigan, Ohio, Indiana, Illinois and Wisconsin.
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