The sun is shining warmly on the Shebeshekong River in Carling Township, where the shore is mainly a marshland of grasses and reeds. Beneath the water’s surface waterweeds grow. Above, at river’s edge five painted turtles bask comfortably on an old gray log. The largest turtle seems the bravest, being the last to plunge back into the shallow water as a canoe and humans approach.
It’s a peaceful natural setting, framed in the distance by the typically breathtaking Georgian Bay scenery of giant pines growing on high faces of pink granite rock.
Seemingly worlds away, yet only a few hundred kilometres in actual distance, two large freight ships pass on the beautiful turquoise blue St. Clair River between Sarnia, Ontario, and Port Huron, Michigan, at Lake Huron’s most southerly tip – their horns blaring in greeting. As the two massive vessels travel past each other, the river is still wide enough for other boats. A pristine white sailboat glides by comfortably.
It’s a busy setting framed in the distance by the large metal docks constructed along the river’s edge, for loading and servicing the many Great Lakes ships regularly passing between Lake Erie and Lake Huron via Lake St. Clair.
How are the two scenes related? They’re linked in a growing concern about how lowering upper Great Lakes’ water levels is impacting wetlands.
The 1960s’ dredging of the St. Clair River to allow passage of Great Lakes vessels is currently being studied by the International Joint Commission on Canadian and United States water, to determine if subsequent erosion in the river has created a drain effect conveying excessive amounts of water out of the upper Great Lakes.
Not only is the lowering of the upper Great Lakes’ water levels causing concern, but also inconvenience, for many. One of the concerns expressed is that lower water levels have already contributed to the drying up of some of the Georgian Bay coastal wetlands, and more could be impacted in the future. Some of these wetlands are considered provincially significant. The Shebeshekong River wetland has already experienced some impact, with lower water levels, exposed banks, and drying shorelines.
It is estimated there may be hundreds of small coastal wetlands in the Georgian Bay area. Every one is unique. Some contain uncommon plant life. Some are spawning grounds for Georgian Bay fish. Waterfowl, mammals and a variety of other wildlife, as well as humans, use these places.
On Partridge Bay, (west of Killbear Provincial Park) which, true to
its name is the habitat of many partridges, humans find their beaches expanded and their water sources further away from their cottages. However beavers have industriously blocked off a section of a stream on the other side of a cottage road. A sparkling woodland pond now exists there, surrounded by raspberry canes and mounds of rock surmounted by pines and other trees.
While the beaver on Partridge Bay have found a solution, having the ingenuity to help themselves, the turtles and other wildlife on the Shebeshekong River are more vulnerable.
The Shebeshekong River water level is down. Large boulders along the edges of the picturesque waterway show water lines from years past. The highest water lines are three or more feet above the existing water level. New docks are stepped down from old ones.
The area is important to wildlife as well as humans. Mergansers and mallards, among other waterfowl, migrate to this area and mate in the spring. A map turtle and its youngster bask together on a large rock.
It’s a peaceful habitat for wildlife. Very shy ducks fly at the sight of a canoe in the distance, the brilliantly coloured males and the duller coloured females beating their feet against the water as their wings pump the air to gain altitude and safety. Canada geese, larger and more confident, paddle slowly and nonchalantly away from the canoe, occasionally emitting their distinctive honks of annoyance and warning.
The air is filled with music from the white-throated sparrow’s patriotic song of O’ Canada, to the red-winged blackbird’s rapturous trill as it sways on a reed and sings to a potential mate – Pick me, pick meee.
Overhead a gull charges a crow who has found a morsel of food from the grounds of one of the cottages. Hawks circle patiently higher overhead and a goose lays low to the ground. Terns swing to and fro over the water, searching diligently.
Along the edges there are black mudflats. Moss grows between the bank of drying grass and reeds and the mud reaching to the water’s new edge. Deer hoof-prints show clearly at the river’s edge, close to a stand of oak trees. Here the ground is littered with acorns, ready to turn wetland into forest if the opportunity presents itself.
The canoeist’s paddle touches bottom easily in most places. A channel marked on the map is now nothing more than a series of puddles.
The Shebeshekong River and Partridge Bay are two of a number of coastal wetlands which have been officially identified by the Ontario Ministry of Natural Resources in the past. Others include: Potato Bay, Quarry Bay, Tobie’s Bay, Sandy Island, Bayfield Inlet and Shawanaga Bay.
The Georgian Bay Association is working with McMaster University this summer and over the summers of 2008 and 2009 to assess these and other coastal wetlands in the Georgian Bay area. The Ontario Ministry of Natural Resources is providing funding to assist with the project.
The Georgian Bay Association was instrumental in drawing attention to the St. Clair River dredging in the 1960s as a possible contributing factor to the lower water levels in the upper Great Lakes. The Georgian Bay Association commissioned a $200,000 hydrological study which was released last summer and indicated the river erosion is a major contributor. That suggestion has been taken up by the International Joint Commission which has made the matter the first part of its five-year study. Climate change, low precipitation, less freeze-up of waters, and more water evaporation will also be studied as contributing factors to the problem.
The Georgian Bay Association is concerned that if declining water levels are not stopped, some coastal wetlands could be lost forever. “Wetlands are needed by 80 to 90 per cent of Great Lakes fish,” says Georgian Bay Association environment chair Mary Muter, a Toronto resident who works from her cottage on Georgian Bay. Ms Muter has assumed the role of Georgian Bay keeper, watching over water quality issues in company with other waterkeeper organizations across Canada and United States. She now has a seat on the International Joint Commission.
On Georgian Bay, “wetlands are developed on silt deposits on the bays and shores,” she explains. In some places there are steep granite shorelines where plant life will not be able to grow down to the water’s new edge, she suggests. In these cases, there is a likelihood the coastal wetlands will be lost, she fears. “So that’s why it’s key to get those assessed and protected.”
The Association is hopeful that if it can be determined that erosion on the St. Clair River is causing declining water levels in the upper Great Lakes, then improvements can be made to stop the erosion.
Meanwhile, assessment of the coastal wetlands will provide an element of protected status.
The assessment work begins this summer. Dr. Pat Chow-Fraser of McMaster University, who is heading the assessment work, says five graduate students will be analyzing the sites for the presence of birds, fish, plants, animals, aquatic insects and worms. This work is aimed at determining whether there would be a physical impact to each of the individual wetland areas if they were exposed to long-term low water levels.
“The impact of low water levels will be very site dependent,” she comments. Factors which could affect each of the sites’ ability to cope include the slope of the bank, presence of seeds, rate of water decline, soil, water quality and light penetration, she explains. Dr. Chow-Fraser says that coastal wetlands toward Severn Sound have already dried up.
Ontario Minister of Natural Resources David Ramsay expressed concern regarding impacts of declining water levels on the Great Lakes.
“We’re very concerned about the potential impact on our natural heritage systems on the Great Lakes and some of the other lakes relative to climate change,” says Mr. Ramsay. “We want to study all these impacts, and how they affect the various landscapes.”
He says the provincial government also wants to learn what can be done about the impacts of climate change.
Water diversion on the Great Lakes, Mr. Ramsay says, has also been a concern. He recalls that when he was first sworn in as Minister of Natural Resources, he worked to improve the Great Lakes Charter Annex agreement regarding water diversion agreements between Ontario, Quebec and eight Great Lakes states. The provincial government is “very pleased” with the improvements which were made in that agreement, he notes.
“It is a huge scale landscape that influences water levels on the Great Lakes,” says Parry Sound MNR biologist Ron Black. “Water level fluctuations are going to cause changes on the wetland habitat. That will be favourable to some species, and unfavourable to others. But communities change and adjust. There is no doubt the environment is in flux and is always changing.”
He says ordinary people can counter adverse impacts of declining water levels on coastal wetlands.
“Naturalist groups can help provide information to appropriate levels of government.” People can get involved with local planning uses, he adds. “We all can try to be good stewards of the land, and use it in a way that doesn’t degrade it.”
Caring For Coastal Wetlands
How are lowering upper Great Lakes’ water levels impacting our coastal wetlands?
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