Since 1995 the overall ecology and the water quality of Cootes Paradise has improved significantly, says Tys Theysmeyer, head of Natural Lands at Royal Botanical Gardens who are in charge of regenerating the marsh.

In 1995, the marsh was declared dead with plant and animal life virtually non-existent, says Theysmeyer. The biggest issue was the immense carp population which have destructive feeding habits, such as the digging up plants, a practice that devastates wetland vegetation and makes it difficult for other species to survive. At its worst the carp population in the bay and marsh was at 100,000 in 1995, weighing in at nearly 0.5 million pounds. Another major problem was sewer overflow and run-off from urban areas including leacheate from Kay Drage Landfill that downgraded water quality in Cootes Paradise, adding to the destruction of plant life.

To Theysmeyer, the three main initiatives that halted the deterioration of Cootes were the construction of a fishway in 1997 to keep the carp out, installation of holding tanks for three of the four sewer overflow locations and a leachate collection system to improve water quality.

According to Theysmeyer, the carp population is now down to about 100. So the fishway has been a success.

Meanwhile cleaner water has allowed native species to once again grow in the marsh. The plants that have returned are water lilies, wild rice, and cattails. Creatures that that have returned include beaver, mink and muskrat; yellow perch and northern pike; wood duck, bald eagle, and Virginia rail; and different frog species.

Although the health of Cootes Paradise has improved by leaps and bounds, much work remains, says Theysmeyer. The goal is to get rid of all of the remaining 100 or so carp and to continue improving water quality.

Algae blooms, which are caused by fertilizers, household cleaning products, and excess carbon and nitrogen being released into the watershed, must also be dealt with.

Other challenges include creating natural and social environments so that migratory birds will stay, and ridding the marsh of harmful, non-native plants. Exotic plants species such as Phragmites (also known as common reed) are a giant, invasive reed grass which stand at 15 feet tall and smother other plant species.

Theysmeyer hopes “… that wetland plant community would include a further 50 hectares of reeds interspersed with open ponds in the shallower western end of the marsh, with the eastern half rimmed with reeds, but remaining largely a mixture of open water and water lilies.”

Several annual clean-up projects offer residents the chance to help advance the health of the marsh. The Great Canadian Shoreline Clean-up occurs in the fall on shores all over the country, including Cootes Paradise. On April 20, RBG and Earth Day Hamilton stage an event where volunteers and visitors can assist in replacing non-native invasive plants with native trees and shrubs; learn about the health of the Great Lakes; and enjoy guided hikes, among other activities.

For more information about these and other events, see the following websites:, and

Rachel Emery is a graduate of Political Science and an avid news-reader. She enjoys writing pieces on political analysis and world events, as well as environmental issues. In her spare time, she enjoys cycling, walking by the water, and rowing.

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