Tommy Thompson Park represents the largest area of existing natural habitat on the central Toronto waterfront and provides one of the best opportunities for habitat creation, restoration and enhancement using principles and techniques that are appropriate with the unique characteristics of the park. One of the main advantages to initiating habitat projects at TTP is that the entire spit of land, with the accompanying embayments, was man-made and initially contained a poor suite of habitats. Through habitat creation and enhancement projects, functional and even critical habitats for a wide range of species are created where none existed before. The habitat work completed to date include some of the best examples of Great Lakes coastal habitat restoration and are being used as a template for additional work outside the GTA.
The ecological approach to TTP development has been guided by the principles of “Conservation by Design”. This is defined as the purposeful act of designing for a variety of natural habitats while combining natural succession principles to create functional, productive areas. The natural area restoration projects are designed to facilitate the growth and natural development of indigenous plant and animal communities. By diversifying the landscape through the creation of varied slope and soil conditions and the addition of native vegetation material, a range of moisture regimes and wind and sun exposures is created, encouraging natural succession through the development of differing plant communities. Planting and seeding facilitates the growth and natural development of indigenous communities by inundating certain areas with vegetation adapted to that specific environment. These areas are then left to grow, reproduce and spread naturally with minimal human intervention.
The natural area restoration and development component can be broken down into four main categories: wetland development, embayment enhancement, terrestrial habitat creation and enhancement and essential habitat creation.
An expected wetland gain of approximately 30 hectares will result from the development of new wetland habitat in Cells One, Two and Three. The objectives are to modify the cell depth in order to cap the existing confined disposal facilities and to establish coastal marsh habitat by creating conditions conducive to the establishment of a diversity of native emergent and submergent plant communities. The productivity of the resulting wetland habitat will be further enhanced through the installation of a diversity of structural habitat.
The goals of the wetland development projects are to:
Establish functional coastal marsh communities;
Increase emergent and submergent vegetation zones;
Increase the diversity and extent of riparian and upland vegetation;
Increase structural habitats and the diversity of substrates;
Increase the diversity of shoreline habitats;
Provide critical habitat components for the resident fish and wildlife communities within the Lake Ontario Waterfront;
Provide educational opportunities for school groups and the public.
There are a total of five Embayments (A, B, C, D, and the East Cove) at TTP. As of 2007 approximately 20% of the Embayment areas have been regenerated or are being naturally regenerated. This work has included major planting nodes to establish vegetation along the shoreline, as well as the creation of essential habitat features such as reproductive zones, nursery/juvenile areas, resting/loafing spots and overwintering areas for fish and other wildlife. Structural fish habitat has also been created in the form of shoals, brush bundles and log cribs within some of the Embayments. The goal of future work in the Embayments is to incorporate further enhancements to create a diverse shoreline consisting of coastal marsh, shrub thickets, mudflats, cobble beaches, sand dunes and wet meadows.
Terrestrial Habitat Creation and Enhancement
The land base of TTP exhibits varying degrees of natural regeneration from bare soil or rubble to meadow/shrub communities, woodlands and wetlands. Two factors have determined the level of success for natural regeneration: surficial soil composition and the elapsed time since active filling and grading. In some cases, unique habitat features such as seasonally flooded pools, mudflats and meadow communities have naturally evolved. However, much of the upland areas at TTP require further modification to create the diversity of habitats required to support a robust and sustainable ecosystem. A variety of restoration techniques will be employed, including landform alteration, drainage design, soil conditioning and planting to create a diverse assemblage of terrestrial habitat communities. Terrestrial habitat creation and enhancement projects will be implemented in locations across the entire land base of TTP, with a focus on the south shore lands recently created by the lake filling process, known as the Toplands.
Essential Wildlife Habitat Creation
Many wildlife species rely on specific habitat features for portions of their life cycles. Emphasis will be placed on creating and enhancing this “essential habitat” by providing features and/or conditions that are required by certain species during their reproduction, rearing, overwintering, staging and migrating activities. Examples of essential wildlife habitat components include the creation of seasonally flooded and protected pools for amphibian reproduction, mudflat areas for migrating shorebirds, flat open areas for nesting colonial waterbirds and sheltered thickets and den sites for over-wintering birds, herpetiles and mammals. These critical habitat components will target resident species, as well as migratory fish and birds.