Mer Bleue, Part I: Ecology

Pink Lady’s Slipper

One place I wanted to take my mother and stepfather but didn’t have time was Mer Bleue, the second largest domed bog in southern Ontario and one of the most beautiful and unique parts of the city’s Greenbelt. Featuring a northern ecosystem more typical of the Arctic than the Ottawa Valley, the Mer Bleue bog is the only wetland in Canada’s Capital Region internationally recognized under the Ramsar Convention on Wetlands.

Sphagnum moss, also known as peat moss, forms the heart of the 3,500-hectare bog. This plant thrives in the cool, acidic, oxygen- and nutrient-poor conditions that characterize northern bogs. When it decomposes, it forms layer upon layer of dead organic matter (called peat), the bog substrate. Because the sphagnum moss tends to grow fastest in the center of the bog, the peat accumulates below and the water table rises. The high water table allows wetland plants to keep growing and for peat to accumulate, increasing the size of the dome over thousands of years. The Mer Bleue bog is about six metres thick in the center of the dome and has taken thousands of years to develop.

More Dragonfly Discoveries…

I went back to Petrie Island the following day, July 3, 2011, to look for Blue Dashers and conduct a count. I started at the marshy area along the west side of the causeway where I observed two male Blue Dashers perching on vegetation above the water, occasionally flying out to chase another insect. I also heard a pair of Virginia Rails calling from among the cattails, and managed to coax one out into the open by playing a recording of its song. I wish that all of the rails were so easy to see! A Great Blue Heron and a single Wood Duck were also present, and again I saw a Green Heron flying to the back of the marsh. There was no sign of the Black Tern I had seen the previous day.