What Makes Stephenson’s Swamp in Scarborough Important?

Stephenson's Swamp

Tucked away in the Lower Highland Creek is Stephenson’s Swamp, a designated Environmentally Significant Area (ESA) and one of the city’s few Provincially Significant Wetlands. What that means is that Stephenson’s Swamp has met specific requirements to make it eligible for special protection to preserve its environmentally significant qualities.

Stephenson’s Swamp is what remains of a once large coastal marsh located at the mouth of Highland Creek. Today it’s part of a wetland complex composed of four individual wetlands totaling an area of 7.6 hectares. To give you an idea of its size, that’s bigger than the entire Rogers Centre complex, which measures only 5.14 hectares!

Forest swamps such as Stephenson’s Swamp were once the most common type of wetland prior to European settlement, but today coastal wetlands such as these are rare on Lake Ontario. That’s why having a wetland complex of this size is such an important ecological feature.

Not only is the wetland complex itself rare, but it’s also a breeding area for several uncommon species such as the blue-gray gnatcatcher and yellow-spotted salamander, as well as being home to rare flora like dotted wolffia and radiate sedge.

In the past, the area around the wetland complex has been altered by land filling, railway construction and increasing urbanization. Problems include an inconsistent water flow from Centennial Creek and the presence of exotic species such as purple loosestrife and carp.

Wetland conservation is a key component of maintaining local biodiversity. Not only are many amphibian species particularly susceptible to changes in wetland health, but they also require a close relationship between aquatic and terrestrial habitats for breeding. Although these conditions are difficult to maintain within such a fragmented environment, they do occur within this wetland complex, making it an important site for many sensitive species.

Wetland and Salamander Monitoring at TRCA

 

Did you know?

There are actually four Environmentally Significant Areas in the Highland Creek Watershed: Stephenson’s Swamp, Highland Forest, Hague Park and the Morningside Park Forest. Find out more about these and other watershed features on the Highland Creek section of the TRCA website!