Restoring the Toronto Zoo’s Natural Spaces
Over the last two years, Toronto Zoo’s Adopt-A-Pond Wetland Conservation Programme has done fabulous work to restore some of the natural spaces on the Zoo’s property. To improve breeding sites for our wonderful amphibian friends such as Gray Treefrogs and Wood Frogs, two tableland ponds were created in the summer of 2013 and 2014. With the help of planting native species, tadpoles were seen using the space less than a year after this new habit was created.
Adopt-A-Pond’s current restoration project is the rejuvenation of Weston Pond! Weston Pond is located on the west side of the Toronto Zoo in the Canadian Domain, and is adjacent to the main Rouge River. This pond may be familiar to Zoo visitors as the large green soup looking pond at the bottom of a steep hill. Weston Pond is an important center piece to the Zoo’s famously Canadian exhibits; an area where visitors can see grizzly bears, moose, lynx, bald eagles, cougars and even a few raccoons. The pond has been present for many years, at least since the 1950s, and now serves to delight waterfowl enthusi
asts with a number of nesting ducks and swans. There is even an interpretive building along the east shore of the pond where birders can set up their equipment for some great nesting shots. Past observations of Painted turtles and Species at Risk Snapping turtles and Blanding’s turtles, have been known to inhabit or forage for food in the pond; however over the past decade these sightings have dropped drastically.
Over time Weston Pond has become a poorly functioning ecosystem. Some problems include a damaged spill way and inlet/outlet into the river, overgrowth of plants, increased shallowing of the water through sedimentation, and a shoreline over grown with invasive species containing very little diversity in terms of hummocks, bays or inlets. The pond shallowness is creating a big problem with temperature control and plant growth. The pond was always shallow with areas between 1 to 2 meters deep. However, the current water column depth in the pond is less than a meter, and the over growth of plants has created a thick sludge bottom of dead algae and duck weed. The shallow water and over growth of plants make this pond hot! This hot, anoxic (low oxygen), environment greatly hinders the ability of frogs, turtles and fish from using this area especially for overwintering purposes.
To help improve this pond Adopt-A-Pond partnered with the Toronto and Region Conservation Authority Restoration Services, experts in restoring wetland habitat for Southern Ontario wildlife!
TRCA has now completed Phase 1 of the Project Plan including bathymetric (underwater topography), topographic and drainage surveys of the pond, soil sampling, seed bank sampling, and engineer consultation regarding water control structures and berm integrity. TRCA is currently implementing Phase 2 of the Project, which involves dig permits, construction and enhancement of unique wildlife habitat features, as well as water level management to improve the water quality in the pond.
Some of the wonderful things TRCA have enhanced so far include:
- Rebuilding and creating island habitat for turtles and waterfowl by providing a comfortable, safe place to nest away from the majority of predators
- Re-contouring the shoreline to create microhabitats and decrease predation by animals such as raccoons who easy hunt along linear shorelines
- Digging deeper pockets in the pond to create differ habitat depths and remove the buildup of sludge
- Decommissioning the damaged a water control structure and adding a new one to control water levels
- Clearing sediment form culverts and creating a new spillway berm to prevent pathway flooding and exhibit flooding
- Improve the fencing and the trail base along Traditional Knowledge Trail
In the future Adopt-A-Pond and TRCA will also be planting along the shoreline and add habitat structures such as logs, rocks, etc. for basking areas to enhance turtle and waterfowl habitat in the pond.
Most importantly TRCA plans will increase the emergent vegetation along the shoreline, which will add valuable wildlife habitat, limit the effects of situation, and prevent large algae blooms from dominating the pond.
If you looked at Weston Pond right now it looks like a bit of a mess. Water levels in the pond have been lowered to allow for seeds along the outside banks of the pond to germinate, and start growing. When the water levels are raised, the newly established plants will have a better chance for survival, providing abundant food and shelter to the wildlife that lives here.
This summer you may see ducks or muskrats browsing on the plants, or mother animals with their young hiding in the sheltered areas. When the water levels of the pond are raised to their new levels in 2016, the animals that live here will find an area that is safe, full of food, and a great place to raise their families.
This wetland restoration project was completed with financial support from a variety of partners. We would like to thank the Toronto and Region Conservation Authority, the Ministry of Natural Resources and Forestry’s Land Stewardship and Habitat Restoration Program, and Environment Canada’s National Wetland Conservation Fund.