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 oligotrophic conditions. The periphery of the bog is encircled by a mineral-enriched lagg that 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 Mer Bleue is a boreal peatland, a type of ecosystem that 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 spp.), small cranberry (Vaccinium oxycoccos), bog-laurel (Kalmia polifolia), and sheep-laurel (Kalmia angustifolia). 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 spp.), and a variety of sedges (Carex spp.). There are several aspen islands in the centre of Mer Bleue consisting of an overstory of aspen and an understory dominated by bracken fern (Pteridium spp.). The edges of the islands are surrounded by small