Mer Bleue Conservation Area
Encyclopedia
The Mer Bleue Conservation Area is a 33.43 km² (12.9 sq mi)
protected area east of Ottawa
in Eastern Ontario
, Canada. Its main feature is a sphagnum
bog
which is situated in an ancient channel of the Ottawa River
and is a remarkable boreal-like ecosystem normally not found this far south. Stunted black spruce
, tamarack, bog rosemary, blueberry
, and cottongrass
are some of the unusual species that have adapted to the acidic waters of the bog.
The area provides habitat for a large number of species, including beaver
, muskrat
, waterfowl, and the rare Spotted Turtle
(Clemmys guttata). A 1.2 km boardwalk
allows visitors to explore a section of the bog. There are hiking
trails which follow raised areas along the edges of the bog and cross-country skiing
trails for use in winter. The conservation area is managed by the National Capital Commission
.
The value of this unique wetland was not always recognized. During World War II
, the Royal Canadian Air Force
used this area for bombing practice. Now, this area has been designated as a Wetland of International Significance under the Ramsar Convention
since October 1995.
The name "Mer Bleue" (French
, meaning "blue sea") is thought to describe the bog's appearance when it is covered in morning fog.
In the mid 1950s, the Federal Government of Canada expropriated the farmland, making it part of Ottawa's Greenbelt
. Today, the bog is reserved mainly for recreational and scientific purposes.
. This channel was eroded into the floor of the Champlain Sea
, which invaded the Ottawa Valley
some 12 000 years ago. Bedrock topography consists of two north north-east/south south-west trending ridges. Surficial material consists of some glacial till, thick marine clay, and freshwater and deltaic deposits grading from coarse sand to clay. Peat
deposits in the bog proper are up to 6 metres (19.7 ft) thick.
There are two sand ridges that extend from the west towards the center of the conservation area. These two parallel ridges divide the bog in three sections. The northern ridge (Dolman Ridge) used to have farms which were expropriated in 1958 and subsequently removed, while the southern ridge (Borthwick Ridge) continues to have a few farms on it and provides access to the visitor boardwalk.
The hydrological features at this site are most unusual. Being a domed bog, water enters the bog mainly from natural precipitation creating oligotroph
ic conditions. The periphery of the bog is encircled by a mineral-enriched lagg which maintains a base water level for the bog. Drainage is poor due to underlying clay deposits as well as numerous beaver dams. Water eventually drains slowly both westward into Greens Creek and eastward into Bear Brook. However, water levels remain at or near the surface of the bog for most of the year. Saline ground-water sources are found under the organic overburden. A number of artificial ditches were dug in the bog for land reclamation or drainage of adjacent lands, however, most are no longer functioning efficiently due to the many beaver impoundments and gradual sedimentation that has occurred along their lengths.
Mer Bleue is a boreal peatland, a type of ecosystem which is usually found in the boreal forest to the north. The sphagnum bog contains two main types of vegetation - the black spruce forest and the open heath vegetation. The black spruce (Picea mariana) forest is dominated by black spruce with some growth of larch (Larix laricina), trembling white aspen (Populus tremuloides) and grey or white birch (Betula spp.).
Sphagnum mosses are the dominant low lying form of vegetation in the bog. About 12 species of heaths (members of the family Ericaceae) thrive in the bog. The most common are Labrador tea (Rhododendron groenlandicum), leatherleaf (Chamaedaphne sp.), small cranberry (Vaccinium oxycoccus), bog-laurel (Kalmia polifolia), and sheep-laurel (Kalmia augustifolia). At least nine species of orchids (family Orchidaceae) are found in Mer Bleue along with a variety of cottongrasses (Eriophorum spp.) and sedges (Carex spp.) in the family Cyperaceae.
The marsh areas around Mer Bleue are characterized by plants such as cattails (Typha latifolia, alders (Alnus rugosa), willows (Salix sps.), and a variety of sedges (Carex spp.). There are several aspen islands in the center of Mer Bleue consisting of an overstory of aspen and an understory dominated by bracken fern (Pteridium sp.). The edges of the islands are surrounded by small bands of cattail and some alder growth.
The ridges of the site extend from the center of the conservation area westwards. There is a wide mixture in the vegetation from early succession poplars and shrubs to some very large mature specimens of white pine, maple and ash. A section of this area includes a variety of hard and softwood plantations established by the Canadian Forest Service
.
. Drainage was formerly through small creeks, which now have been modified through a series of ditches dug in the late 19th century. These ditches are no longer functioning efficiently due to the many beaver ponds which started up in the late 1950s. As in a typical bog, the water level is at or near the surface for most of the year. Much of the bog is surrounded by the "lagg" which is basically a moat of standing or slow flowing water found between the outer perimeter of the bog and the land. Flooding is controlled naturally through beaver dams and the ability of sphagnum to absorb large amounts of water.
The bog receives most of its water in the form of atmospheric precipitation. Flow velocities of ground and surface waters are very low given the impermeability of the underlying clay soils, the absorption qualities of Sphagnum and the presence of numerous beaver dams. Shoreline stabilization is not a significant concern as the impact of water on the ridges is minimal and most of the land is relatively flat.
habitat which is normally found much farther north.
At least 22 mammal species are present in or around Mer Bleue. Aquatic furbearers such as beaver
(Castor canadensis), muskrat
(Ondatra zibethicus) and mink (Neovison vison
) live in the surrounding marshes. The Spotfin Shiner (Cyprinella spiloptera), regionally rare, is found in Bear Brook Creek. Two rare beetles, Stenolophus magnacephalus and Agonum darlingtoni occur here. The Spotted Turtle
(Clemmys guttata), a rare species in Canada, is found in the center of the bog.
1 E7 m²
To help compare sizes of different geographic regions, we list here areas between 10 km2 and 100 km2...
protected area east of Ottawa
Ottawa
Ottawa is the capital of Canada, the second largest city in the Province of Ontario, and the fourth largest city in the country. The city is located on the south bank of the Ottawa River in the eastern portion of Southern Ontario...
in Eastern Ontario
Eastern Ontario
Eastern Ontario is a subregion of Southern Ontario in the Canadian province of Ontario which lies in a wedge-shaped area between the Ottawa River and St. Lawrence River...
, Canada. Its main feature is a sphagnum
Sphagnum
Sphagnum is a genus of between 151 and 350 species of mosses commonly called peat moss, due to its prevalence in peat bogs and mires. A distinction is made between sphagnum moss, the live moss growing on top of a peat bog on one hand, and sphagnum peat moss or sphagnum peat on the other, the...
bog
Bog
A bog, quagmire or mire is a wetland that accumulates acidic peat, a deposit of dead plant material—often mosses or, in Arctic climates, lichens....
which is situated in an ancient channel of the Ottawa River
Ottawa River
The Ottawa River is a river in the Canadian provinces of Ontario and Quebec. For most of its length, it now defines the border between these two provinces.-Geography:...
and is a remarkable boreal-like ecosystem normally not found this far south. Stunted black spruce
Black Spruce
Picea mariana is a species of spruce native to northern North America, from Newfoundland west to Alaska, and south to northern New York, Minnesota and central British Columbia...
, tamarack, bog rosemary, blueberry
Blueberry
Blueberries are flowering plants of the genus Vaccinium with dark-blue berries and are perennial...
, and cottongrass
Common Cottongrass
Common Cottongrass is a plant from the sedge family, so even though it looks like a form of grass, technically it is not. It grows in acidic wetlands and peat bogs all over northern parts of Europe, Asia and North America...
are some of the unusual species that have adapted to the acidic waters of the bog.
The area provides habitat for a large number of species, including beaver
American Beaver
The North American Beaver is the only species of beaver in the Americas, native to North America and introduced to South America. In the United States and Canada, where no other species of beaver occurs, it is usually simply referred to as "beaver"...
, muskrat
Muskrat
The muskrat , the only species in genus Ondatra, is a medium-sized semi-aquatic rodent native to North America, and introduced in parts of Europe, Asia, and South America. The muskrat is found in wetlands and is a very successful animal over a wide range of climates and habitats...
, waterfowl, and the rare Spotted Turtle
Spotted Turtle
The Spotted turtle , the only current species of Clemmys, is a small, semi-aquatic turtle that reaches a carapace length of upon adulthood. Their broad, smooth, low dark-colored upper shell, or carapace, ranges in its exact colour from black to a bluish black with a number of yellow tiny round spots...
(Clemmys guttata). A 1.2 km boardwalk
Boardwalk
A boardwalk, in the conventional sense, is a wooden walkway for pedestrians and sometimes vehicles, often found along beaches, but they are also common as paths through wetlands, coastal dunes, and other sensitive environments....
allows visitors to explore a section of the bog. There are hiking
Hiking
Hiking is an outdoor activity which consists of walking in natural environments, often in mountainous or other scenic terrain. People often hike on hiking trails. It is such a popular activity that there are numerous hiking organizations worldwide. The health benefits of different types of hiking...
trails which follow raised areas along the edges of the bog and cross-country skiing
Cross-country skiing
Cross-country skiing is a winter sport in which participants propel themselves across snow-covered terrain using skis and poles...
trails for use in winter. The conservation area is managed by the National Capital Commission
National Capital Commission
The National Capital Commission , is a Canadian Crown corporation that administers the federally owned lands and buildings in Canada's National Capital Region, including Ottawa, Ontario and Gatineau, Quebec.The NCC was created in 1959, replacing the Federal District Commission , which had been...
.
The value of this unique wetland was not always recognized. During World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, the Royal Canadian Air Force
Royal Canadian Air Force
The history of the Royal Canadian Air Force begins in 1920, when the air force was created as the Canadian Air Force . In 1924 the CAF was renamed the Royal Canadian Air Force and granted royal sanction by King George V. The RCAF existed as an independent service until 1968...
used this area for bombing practice. Now, this area has been designated as a Wetland of International Significance under the Ramsar Convention
Ramsar Convention
The Ramsar Convention is an international treaty for the conservation and sustainable utilization of wetlands, i.e., to stem the progressive encroachment on and loss of wetlands now and in the future, recognizing the fundamental ecological functions of wetlands and their economic, cultural,...
since October 1995.
The name "Mer Bleue" (French
French language
French is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...
, meaning "blue sea") is thought to describe the bog's appearance when it is covered in morning fog.
History
Europeans began farming in the area surrounding the bog in the 1830s. Active exploitation of the bog itself occurred from the 1870 to the early 20th century and included activities such as logging, hunting, blueberry picking, farming, peat extraction, development for transportation/utility corridors, recreation, and scientific investigations.In the mid 1950s, the Federal Government of Canada expropriated the farmland, making it part of Ottawa's Greenbelt
Greenbelt (Ottawa)
The Greenbelt is a crescent of land within the present-day boundaries of the city of Ottawa, Ontario, Canada, in which real estate development is strictly controlled. It begins at Shirleys Bay in the west and extends to Green's Creek in the east...
. Today, the bog is reserved mainly for recreational and scientific purposes.
Physical features
Mer Bleue is located in the southern melt water channel of the post-glacial Ottawa RiverOttawa River
The Ottawa River is a river in the Canadian provinces of Ontario and Quebec. For most of its length, it now defines the border between these two provinces.-Geography:...
. This channel was eroded into the floor of the Champlain Sea
Champlain Sea
The Champlain Sea was a temporary inlet of the Atlantic Ocean, a paratropical subsea or epeiric sea created by the retreating glaciers during the close of the last ice age...
, which invaded the Ottawa Valley
Ottawa Valley
The Ottawa Valley is the valley along the boundary between Eastern Ontario and Western Quebec along the Ottawa River. The valley is the transition between the Saint Lawrence Lowlands and the Canadian Shield...
some 12 000 years ago. Bedrock topography consists of two north north-east/south south-west trending ridges. Surficial material consists of some glacial till, thick marine clay, and freshwater and deltaic deposits grading from coarse sand to clay. Peat
Peat
Peat is an accumulation of partially decayed vegetation matter or histosol. Peat forms in wetland bogs, moors, muskegs, pocosins, mires, and peat swamp forests. Peat is harvested as an important source of fuel in certain parts of the world...
deposits in the bog proper are up to 6 metres (19.7 ft) thick.
There are two sand ridges that extend from the west towards the center of the conservation area. These two parallel ridges divide the bog in three sections. The northern ridge (Dolman Ridge) used to have farms which were expropriated in 1958 and subsequently removed, while the southern ridge (Borthwick Ridge) continues to have a few farms on it and provides access to the visitor boardwalk.
The hydrological features at this site are most unusual. Being a domed bog, water enters the bog mainly from natural precipitation creating oligotroph
Oligotroph
An oligotroph is an organism that can live in an environment that offers very low levels of nutrients. They may be contrasted with copiotrophs, which prefer nutritionally rich environments...
ic conditions. The periphery of the bog is encircled by a mineral-enriched lagg which maintains a base water level for the bog. Drainage is poor due to underlying clay deposits as well as numerous beaver dams. Water eventually drains slowly both westward into Greens Creek and eastward into Bear Brook. However, water levels remain at or near the surface of the bog for most of the year. Saline ground-water sources are found under the organic overburden. A number of artificial ditches were dug in the bog for land reclamation or drainage of adjacent lands, however, most are no longer functioning efficiently due to the many beaver impoundments and gradual sedimentation that has occurred along their lengths.
Ecological features
Sphagnum mosses are the dominant low lying form of vegetation in the bog. About 12 species of heaths (members of the family Ericaceae) thrive in the bog. The most common are Labrador tea (Rhododendron groenlandicum), leatherleaf (Chamaedaphne sp.), small cranberry (Vaccinium oxycoccus), bog-laurel (Kalmia polifolia), and sheep-laurel (Kalmia augustifolia). At least nine species of orchids (family Orchidaceae) are found in Mer Bleue along with a variety of cottongrasses (Eriophorum spp.) and sedges (Carex spp.) in the family Cyperaceae.
The marsh areas around Mer Bleue are characterized by plants such as cattails (Typha latifolia, alders (Alnus rugosa), willows (Salix sps.), and a variety of sedges (Carex spp.). There are several aspen islands in the center of Mer Bleue consisting of an overstory of aspen and an understory dominated by bracken fern (Pteridium sp.). The edges of the islands are surrounded by small bands of cattail and some alder growth.
The ridges of the site extend from the center of the conservation area westwards. There is a wide mixture in the vegetation from early succession poplars and shrubs to some very large mature specimens of white pine, maple and ash. A section of this area includes a variety of hard and softwood plantations established by the Canadian Forest Service
Canadian Forest Service
The Canadian Forest Service is a sector of the Canadian government department of Natural Resources Canada. Part of the federal government since 1899, the CFS is a science-based policy organization responsible for promoting the sustainable development of Canada's forests and competitiveness of the...
.
Hydrological values
Mer Bleue drains both westward into Green's Creek and eastward into Bear BrookBear Brook (Ontario)
Bear Brook is a small creek in the Eastern Ontario region, mostly located within the municipal boundaries of Ottawa and Clarence–Rockland. It forms in the fields and forests just north of Edwards, and flows in a mostly eastern direction to its mouth in the South Nation River...
. Drainage was formerly through small creeks, which now have been modified through a series of ditches dug in the late 19th century. These ditches are no longer functioning efficiently due to the many beaver ponds which started up in the late 1950s. As in a typical bog, the water level is at or near the surface for most of the year. Much of the bog is surrounded by the "lagg" which is basically a moat of standing or slow flowing water found between the outer perimeter of the bog and the land. Flooding is controlled naturally through beaver dams and the ability of sphagnum to absorb large amounts of water.
The bog receives most of its water in the form of atmospheric precipitation. Flow velocities of ground and surface waters are very low given the impermeability of the underlying clay soils, the absorption qualities of Sphagnum and the presence of numerous beaver dams. Shoreline stabilization is not a significant concern as the impact of water on the ridges is minimal and most of the land is relatively flat.
Regionally significant vegetation
- Beech-maple forestBeech-maple forestA beech-maple forest is a climax mesic closed canopy hardwood forest. It is primarily composed of American Beech and Sugar Maple trees which co-dominate the forest and which are the pinnacle of plant succession in their range...
s (upland tolerant deciduous forest) rare in Ottawa-Carleton region. - Swampy forests of Maple, Cedar, and Hemlock (lowland tolerant forests) are regionally significant.
- Black spruceBlack SprucePicea mariana is a species of spruce native to northern North America, from Newfoundland west to Alaska, and south to northern New York, Minnesota and central British Columbia...
-larchLarchLarches are conifers in the genus Larix, in the family Pinaceae. Growing from 15 to 50m tall, they are native to much of the cooler temperate northern hemisphere, on lowlands in the north and high on mountains further south...
forests (lowland intolerant coniferous forests), rare in the Ottawa district. - Open bog, low-shrub bog and treed bog are highly significant within an Ottawa District and Southern Ontario context.
- Bog pool is regionally significant.
Nationally significant flora
- Porsild's cottongrass (Eriophorum x porsildii, a hybrid of E. vaginatum and E. chamissonis), Cyperaceae
- Southern twayblade (Listera australis), Orchidaceae
- Torrey's manna grass (Torreyochloa pallidaTorreyochloa pallidaTorreyochloa pallida is a species of grass known by the common name pale false mannagrass. It is native to North America, especially the east and west sides. It grows in wet habitat, such as rivers, lakesides, bogs, and swamps. It is a rhizomatous perennial grass producing thick, erect to...
), Poaceae
Provincially significant flora
- Black-berried highbush blueberry (Vaccinium corybosum)
- Downy goldenrod (Solidago puberula)
- Drooping manna grass (Glyceria x laxa)
- Folliculata sedge (Carex folliculata)
- Greene's rush (Juncus greenei)
- Ground pine (Lycopodium obscurumLycopodium obscurumLycopodium obscurum, commonly called ground pine or princess pine, is a species of clubmoss in the family Lycopodiaceae. It is a close relative of other treelike Lycopodium such as L. dendroideum and L. Hickeyi. It is distributed from Alabama to the east coast of the United States, and north into...
) - Hayden's sedge (Carex haydenii)
- Heart-leaved tearthumb (Polygonum arifolium)
- Large purple-fringed orchid (Habenaria fimbriata)
- Long manna grass (Glyceria melicaria)
- Marsh dandelion (Taraxacum palustre)
- New England sedge (Carex novae-angliae)
- Seaside dock (Rumex maritimusRumex maritimusRumex maritimus is an annual plant species of the genus Rumex.-External links:****...
) - Slashed avens (Geum laciniatumGeum laciniatumGeum laciniatum is a member of the Rosaceae family. It is a perennial forb, native to eastern North America. -External links:*...
) - Twin-scapped bladderwort (Utricularia geminiscapaUtricularia geminiscapaUtricularia geminiscapa, the hiddenfruit bladderwort, is a perennial, medium-sized species of aquatic bladderwort. This species occurs naturally in the northeastern USA and Canada with one record from British Columbia in Western Canada...
) - White-fringed orchid (Platanthera blephariglottisPlatanthera blephariglottisPlatanthera blephariglottis, commonly known as the White-fringed Orchid or White-fringed Orchis, is a species of orchid of the genus Platanthera...
)
Southern Ontario significant flora
- Alpine cottongrass (Scirpus hudsonianus)
- Fernald's sedge (Carex merritt-fernaldii)
- Flat-topped hawkweed (Hieracium umbellatum)
- Prostrate sedge (Carex chordorrhizaCarex chordorrhizaCarex chordorrhiza, commonly called creeping sedge or string sedge, is a species of perennial plant in the family Cyperaceae with Holarctic distribution growing in acidic bogs.-Growth form and classification:...
) - Small bur-reed (Sparganium minimum)
- Sticky everlasting (Gnaphalium viscosum)
Fauna
The bog has a number of significant fauna because of its relatively undisturbed natural habitat and its uniqueness in representing a borealBoreal ecosystem
The term boreal is usually applied to ecosystems localized in subarctic and subantarctic zones, although Austral is also used for the latter....
habitat which is normally found much farther north.
At least 22 mammal species are present in or around Mer Bleue. Aquatic furbearers such as beaver
American Beaver
The North American Beaver is the only species of beaver in the Americas, native to North America and introduced to South America. In the United States and Canada, where no other species of beaver occurs, it is usually simply referred to as "beaver"...
(Castor canadensis), muskrat
Muskrat
The muskrat , the only species in genus Ondatra, is a medium-sized semi-aquatic rodent native to North America, and introduced in parts of Europe, Asia, and South America. The muskrat is found in wetlands and is a very successful animal over a wide range of climates and habitats...
(Ondatra zibethicus) and mink (Neovison vison
American Mink
The American mink is a semi-aquatic species of Mustelid native to North America, though human intervention has expanded its range to many parts of Europe and South America. Because of this, it is classed as Least Concern by the IUCN. Since the extinction of the sea mink, the American mink is the...
) live in the surrounding marshes. The Spotfin Shiner (Cyprinella spiloptera), regionally rare, is found in Bear Brook Creek. Two rare beetles, Stenolophus magnacephalus and Agonum darlingtoni occur here. The Spotted Turtle
Spotted Turtle
The Spotted turtle , the only current species of Clemmys, is a small, semi-aquatic turtle that reaches a carapace length of upon adulthood. Their broad, smooth, low dark-colored upper shell, or carapace, ranges in its exact colour from black to a bluish black with a number of yellow tiny round spots...
(Clemmys guttata), a rare species in Canada, is found in the center of the bog.
See also
- Greenbelt (Ottawa)Greenbelt (Ottawa)The Greenbelt is a crescent of land within the present-day boundaries of the city of Ottawa, Ontario, Canada, in which real estate development is strictly controlled. It begins at Shirleys Bay in the west and extends to Green's Creek in the east...
- List of Ramsar wetlands of international importance