Get Your Feet Wet! Marshes, Bogs & Fens | Carolinian Canada

Get Your Feet Wet! Marshes, Bogs & Fens

Marshes, bogs and fens are the subject of folklore as rich as the life that teems in them. According to legend, they are home to witches and spirits and in their dark, mucky waters, lurk snakes and toads. In reality, these inaccessible habitats are a haven for species at risk. Carolinian Canada Great Lakes coasts have many marshes that are among the most important stopovers for major migratory flyways in North America. Shallow marshes with up to 2 m of standing are the most familiar of the marshes because they are often dominated by a single species of plant such as cattails. Rarely found in Carolinian Canada, bogs and fens contain some of this areas more typically northern species.

Wetlands perform important environmental services including water cleansing and groundwater protection. For example, Cattails absorb toxic metals such as mercury and lead. Many municipalities rely on wetlands to purify their drinking water. The cost to replace natures free services with mechanical water purification systems would be astronomical. Wetlands also prevent erosion and flooding by acting as sponges, soaking up excess water and protecting the landscape against the effects of drought.

Protected Wetlands

  • One of the most accessible bogs in Carolinian Canada is the Sifton Botanical Bog in London managed and monitored for impacts from surrounding city developments.
  • The boardwalks of Point Pelee National Park offer excellent opportunities to view vast coastal marshes up close.
  • Many wetlands were originally protected and stewarded by hunting groups, such as the St. Clair marshes.
  • The 289 ha St. Clair National Wildlife Area has is a Ramsar site under the Convention on Wetlands of International Importance.
  • Long Point Bird Observatory was the first organization of its type in North America with a field station operated by Bird Studies Canada situated on the tip of the 32 km spit of dunes and marshes, within the Long Point Biosphere Reserve.
  • Provincially significant wetlands are protected through provincial policy as applied by municipalities during the planning process.

What’s the problem?

In the past, the tendency has been to drain wetlands. Now we know that this can result in significant problems for nearby communities such as basement flooding and contaminated drinking water. Less than 20% of the original wetlands in Ontario are still in existence. Despite major advances in planning policy, many small wetlands are lost each year. Even protected wetlands are subject to degradation, siltation, pollution and invasion by alien plants. Wetland plants and animals are particularly vulnerable to pollution and contaminants that accumulate from the surrounding landscape.

Recovery Strategies

  • Blanchard’s Cricket Frog
  • King Rail
  • Least Bittern
  • Eastern Fox Snake

Habitat Saving Ideas

Get Wet! The “Wet Kit” is a comprehensive resource for all things wetland

Get Support! Many landowners are protecting wetlands and restoring wet marginal areas to important wildlife habitat with technical and financial assistance from the Wetland Habitat Fund or Ducks Unlimited

Get A Trail! Protect wetlands during local planning processes from draining and encroachment by development. A large buffer around a wetland is important to provide eco-friendly trails, away from sensitive habitats.

Buzz Off! Maintain natural vegetation in wetlands, nearby uplands and buffer areas including leaving dead trees standing. Avoid mowing in a wetland buffer zone and otherwise disturbing the wildlife. Wait until mid-July to mow upland areas so that waterfowl and other birds can nest. This will encourage a healthy ‘web of life’ that controls insects naturally.

To Dump or not to Dump? Respect the local marshes and ditches. Don’t use wetlands as dumping grounds for trash, compost, garden debris or hazardous waste. Aside from the dangers to wildlife, you may irreparably harm the ecosystem, contaminate groundwater and unwittingly introduce invasive aliens.

What goes in must come out! Eliminate or reduce polluted runoff from lawns, roads and fields. If chemical fertilizers and pesticides are necessary, use them sparingly and away from wet areas.


Plant Communities @ Risk

American Lotus Floating-leaved Shallow Aquatic Type

(S1) Very Rare in Ontario

The spectacular ‘giant waterlily’, the American Lotus dominates this community. The water-depth requirements are quite specific, so patches of the species migrate with changing lake levels. This species is in the same genus as the pink-flowered sacred lotus of eastern Asia, whose rhizomes are eaten as the Japanese vegetable, renkon.

Where? In Canada, the shoreline marshes of Lake Ontario and Lake St. Clair

How many? Several thousand plants in about 6 main sites

What’s the problem? Loss of habitat, lake level changes.

How to Help! Protect natural shorelines.

Kettle Peatlands

Leatherleaf Shrub (G3G4S3)

Highbush Blueberry Shrub (G2QS1S2)

Tamarack-Leatherleaf Treed (G3G4S3)

Globally Rare, Rare in Ontario

Bogs were formed after the last ice-age when huge lumps of ice carved depressions into Ontario’s landscape. Known as Kettle Peatlands, these bogs are characterized by a thick layer of Sphagnum moss, and peat that keeps the bog acidic. Sedges, shrubs and sometimes stunted Spruce or Tamarack grow in concentric rings.


Meadow marshes

Shrubby Cinquefoil Coastal (G2?S1)

Wet Bluejoint-Prairie Slough Grass Mineral (G2G3S1)

Prairie Slough Grass Organic (G2G3S3)

Globally rare, Very Rare in Ontario

Meadow marshes mark the transition between upland and wetland sites and often contain a rich mix of grasses, sedges and broad-leaved herbs. They are only seasonally flooded and usually dry out by mid summer.


Graminoid Coastal Meadow Marsh

G2?S2. Globally rare, rare in Ontario.

These Meadow Marshes are restricted to shallow water along gently sloping shorelines, beaches and dunes. They appear and disappear as lake levels change. The bottom is coarse sand, gravel or bedrock and nutrient levels are low. The few plants that can grow in these conditions are usually small, sparsely scattered and rare. Rushes and reeds are the dominant plants.

Where? Globally these communities are restricted to shallow shorelines of the lower Great Lakes. In Canada they occur along the shores and beaches of Lakes Huron, Erie and Ontario.

What’s the problem? Threats include changes in Great Lakes levels, growth of new species on stabilized shorelines, shoreline development, trampling, and management of beaches for recreation.

How to Help! Maintain natural shorelines and integrate natural areas into recreational and developed lands.


Species @ Risk

Swamp Rose-mallow (Hibiscus moscheutos)

G3S2. Globally rare. Special Concern in Canada

The Swamp Rose-mallow grows to 2 m high with large pink flowers. It is usually found in open, coastal marshes, but occasionally in open wet woods, thickets and ditches.

Where? In Canada, mainly along the shores of Lake Erie and Lake St. Clair

How many? There are tens of thousands of individuals of this species in about 50 locations in southern Ontario. Only a few sites have large populations over 1,000 individuals. Most sites have only 1 to a few plants.

What’s the problem? Wetland loss and degradation, invasion by Phragmites and hybrid cattail

How to Help! Protect large coastal marshes.


American Water-willow (Justicia americana)

G5S1 Threatened in Canada. Vulnerable in Ontario

This aquatic herb is 20 to 100 cm high with white or pale violet, tube-shaped flowers. It prefers areas of hard water in coastal wetlands and streams.

Where? In Canada, this species is at the northern edge of its range. It grows along the north shore of the St. Lawrence River near Montreal, Quebec and along the shore of Lake Erie in Ontario.

How many? Historically recorded at eight sites in the two provinces, it has disappeared from several of these. The total number of known stems in Canada is about 400,000, and this has changed little over the last 15 years.

What’s the problem? Much of the suitable habitat has been altered or destroyed by residential, industrial and recreational development. It is thought to be sensitive to industrial pollution. Invasive species such as Phragmites may also threaten it.

How to Help! Protect natural shorelines.


King Rail (Rallus elegans)

G4G5S2 Endangered in Canada and Ontario.

This cinnamon-coloured marsh bird has a long curved yellow bill. It prefers large, shallow freshwater marshes dominated by cattails and sedges with scattered shrubs, hummocks of dense vegetation and a mosaic of dry and wet areas.

Where? In Canada, along the lower Great Lakes shorelines

How many? 25 to 50 pairs

What’s the problem? Loss, degradation and contamination of habitat

How to Help! Re-establish pristine, shallow marsh habitat. This species has bred in restored wetlands.


Least Bittern (Ixobrychus exilis)

G5S3 Threatened in Canada. Vulnerable in Ontario.

The Least Bittern is one of the smallest members of the heron and bittern family and its brown plumage provides good camouflage. It prefers extensive marshes over 2 ha in size, nesting in dense stands of cattails, bulrushes or reed grass but may also be found in marshy ditches, streams, ponds and lake edges.

Where? In Canada, this species is found in southern Manitoba, southern Ontario south of the Boreal Forest, southwestern Quebec and southwestern New Brunswick.

How many? Not known. In 1987, thought to be less than 1,000 breeding pairs.

What’s the problem? Loss, degradation and contamination of habitat, high water levels, natural succession, and recreation activities

How to Help! Allow ponds and other wetlands to develop marshy edges rather than clearing to the edges. Control invasive aliens such as Phragmites and purple loosestrife.


Eastern Fox Snake (Elaphe gloydi)

G3S3 Globally rare. Threatened in Canada and Ontario.

This harmless species is Ontario's second largest snake (after the black rat snake), known to reach almost 2 m in length. Its size and eye-catching pattern make it an easy target for people who tend to kill or harm snakes. It is found in shoreline marshes, vegetated dunes, beaches, drainage ditches and nearby farm fields, pastures and woodlots.

Where? In Canada, it is found within several kilometres of the shorelines of Lakes Huron, St. Clair, Erie and Ontario. The global range of this species is restricted to southwestern Ontario, southeastern Michigan and northwestern Ohio.

How many? Likely in the low thousands

What’s the problem? Persecution by people, chemical contamination and degradation of habitat

How to Help! Increased awareness and support of snakes, protection of wetland habitat


Duke’s Skipper (Euphyes dukesi)

G3S2 Globally rare, Rare in Ontario

This short, broad butterfly-like insect with rounded wings measures 32-38cm. The female has a midwing band of 2 or 3 small yellow spots. It prefers marshy areas in or near partially shaded woods with long grasses and sedge patches of the caterpillar’s food plants: Carex lacustris and Carex hyalinolepis.

Where? In Canada, this species is restricted to Essex County, Chatham-Kent and Walpole Island.

How many? Not known. Uncommon and very local with 15 known locations

What’s the problem? Loss or degradation of habitat that sustains the food plants

How to Help! Maintain sedge patches.



Carolinian Canada Coalition 2009

Content based on 2004 guide by Michelle Kanter, Dave Martin, Veronique LeHouk, and Jane Bowles

Many Thanks to Photographers who donated their work for this project:
Jane Bowles, Allen Woodliffe, John Ambrose, Scott Gillingwater, Ben Porchuk, Rob Willson, Mathis Nativik, Shawn Staton, David Mihilik, Joe Milner, George Brackx, Kevin Railsback, Hamilton Conservation Authority, Essex Region Conservation Authority, Margaret Pickles, Leora Berman, Donald Kirk, Upper Thames River Conservation Authority, Larry Lamb, Peggy Hurst, Michelle Kanter, Gregory Peck, Jim Flynn and Rick Battson. 

Thanks also to expert support from Dan Kraus, Mike Nelson and Paul Smith.

 Assistance for this project was provided by the Ministry of Natural Resources.


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