The Ontario Ministry of Natural Resources designated the Greenock Swamp as a Provincially Significant Wetland in 1989. Most of the evaluation file is attached as a scanned pdf; the rest of the file has been lost. Provincial Significance is a formal designation that restricts use of the wetlands without an exception from the province of Ontario.

According to a 2015 assessment for the Saugeen Valley Source Protection Area, the Greenock supports 4 species of Trillium and 8 provincially rare plant species, 6 of which are nationally rare and 2 are threatened. The same report identified over 25 mammal species, 17 species of herpetofauna and over 100 bird species. The Greenock provides habitat for 22 different species of orchid and the purple pitcher plant. The wetland flora need the Greenock to survive in this area, as the majority of the surrounding land is developed for agriculture.

Waterfowl species such as Hooded Merganser, Pied-billed Grebe and Wood Duck have been seen at the Schmidt Lake portion of the Greenock. All waterfowl species are protected from hunting at Schmidt Lake. A 1989 evaluation performed by the Ministry of Natural Resources identified snapping turtles, muskrat, raccoons, beaver, mink, and bullfrog, as observed during the evaluation, exemplifying the array of wetland-dependent biodiversity present in the swamp. Many special features of the Greenock were identified, including use as a breeding and feeding habitat for provincially significant animals like river otter and red shouldered hawk, a known nesting habitat for great blue heron; it was deemed significant for fish spawning, migration of birds, and winter cover for deer (Robinson et al., 1989).

The Greenock Swamp stands out against its intensive and encroaching agricultural surroundings. Around 18% of treed swamps and 47% of shrub swamps have been converted to alternative land uses since colonial settlement in Southern Ontario (Byun et al. 2018), a trend that is mirrored in other mid-latitude regions. Despite the surrounding agricultural setting, the Greenock continues to improve water quality within the Teeswater River, which feeds into the Saugeen River and eventually reaches Lake Huron (Saugeen Conservation, n.d.). As described in this application, the large size of the Greenock also acts as a locally and regionally significant refuge for a variety of biota. The substantial carbon stores in mid-latitude swamps like the Greenock are increasingly being recognized but remain poorly considered in climate models due to lack of assessment (Davidson et al., 2022; Dazé et al., 2022). Thus, the diversity of carbon storage mechanisms that are present in the Greenock Swamp, including episodic-recalcitrant carbon accumulation under broad-leaf trees, continuous-deep carbon accumulation under needle-leafed trees, and peat development in small bog and fen patches makes it a critical site to further our understanding of temperate swamp carbon fluxes in response to encroaching land use change (Dazé et al., 2022). Thus, the Greenock Swamp is a multifaceted ecosystem that provides water purification, biota refuge and habitat, carbon storage, and critical research opportunities for knowledge to improve wetland-climate models.

• Aesthetic/cultural heritage value/provisioning
• Flood storage/mitigation
• Carbon storage
• Water quality improvement
• Education

Southern Ontario has lost over 80% of its wetlands since settlement by European immigrants over the past several hundred years. This has disproportionately affected large wetland areas, making the Greenock Swamp of special significance in a dominantly agricultural area. 

The Greenock is an important part of the traditional territory of the Saugeen Ojibway Nations (SON), which is comprised of the Chippewas of Saugeen and the Chippewas of Nawash Unceded First Nation, which share lands, waters and resources in their territory. The traditional territory of the Saugeen Ojibway Nation occupies over 2 million acres in Southwestern Ontario (SON, 2022). Their Indigenous identity, spirituality, laws, traditions, culture and rights are closely tied to their lands, particularly connection with surface waters including the waters in and around the Greenock (“The Drowned Lands River” https://saugeentimes.com/welcome-to-cargill-a-bruce-county-historical-gem-part-1/). 

Around 1870, Henry Cargill began to purchase portions of the Greenock Swamp until he had full ownership for the purpose of logging. Logging and use of rivers for electricity generation was continued into the early 20th century, when accessible wood had been harvested. The development and prosperity of many towns in the area is closely tied to Cargill’s exploitation of lumber and water in the Greenock. The Cargill and Greenock Swamp Museum and Visitor Centre in the town of Cargill provides visitors with the history of the area. 

According to available eBird data, 160 species have been observed with birders submitting 179 checklists (Fink et al. 2022). Users of the platform have submitted their personal historical records to the site back to 1987 suggesting long-term local interest in wildlife watching at the swamp. The eBird website’s data shows that in the last five years, observers have logged 115 bird species present at the wetland during the breeding season months of the summer, including the Sandhill Crane and Bald Eagle. The large proportion of open water makes the complex an excellent place to observe waterfowl in the fall as they migrate south. 

Guided tours are offered by volunteers throughout the summer to visitors for interpreting the biological features and history of the swamp. Visitors are welcome to use the 7 kilometers of trails all year long. The nearby Cargill and Greenock Swamp Visitor Centre and Museum draws attention to the town’s history intertwined with the swamp.

The vast area of the Greenock Swamp is increasingly credited as a critical local carbon pool for Southern Ontario (Davidson et al., 2022). Using radiocarbon dating, Dazé et al. (2022) provide a detailed analysis of peat accumulation within these temperate swamp soils. Dazé et al. (2022) emphasize that the Greenock Swamp accumulates peat both episodically under the broad-leaf swamp areas in more recalcitrant older forms, and continuously since the Middle Holocene under the needle-leaf swamp soils. This comes as no surprise as mid-latitude swamps, especially mixed swamps (i.e., needle-leaf and broad-leaf trees present), are increasingly recognized for containing important soil carbon stocks (Kolka et al., 2018; Davidson et al., 2022). Further, using areal carbon element analysis, Dazé et al. (2022) report carbon stocks of 60 kg C m-2 for needle-leaf swamp areas, and 13.5-36.0 kg C m-2 for broad-leaf swamp areas, which are comparable or exceed mean values for forested wetland types. The large size, diversity of carbon accumulating environments (i.e., needle-leaf and broad-leaf swamps along with small fens and bogs), mix of recalcitrant and labile carbon storage, and rates of accumulation, have made the Greenock Swamp a critical carbon storage area. More areal mapping is needed for this site to distinguish the proportion of different wetland types within the swamp to provide total carbon storage values for the entire area. Thus, this site acts as a valuable research opportunity to characterizing carbon flux mechanisms within mid-latitude swamps that experience significant human alteration, which have been historically ignored compared to assessments of carbon fluxes in boreal and sub-arctic bogs and fens (Daze et al., 2022).

The Greenock Swamp experiences large amounts of lake-effect snowfall during the wintertime because of its proximity to Lake Huron (Byun et al., 2022). The Greenock Swamp provides storage capacity during times of increased precipitation, which reduces flooding downstream of the swamp (Saugeen Valley Source Protection Area, 2015). 

The Greenock Swamp Wetland Complex improves water quality in the Teeswater River, which flows through the swamp with its tributaries and finally merges with the Saugeen River at the town of Paisley. Water exiting the wetlands to join the river has lower alkalinity, ammonia (NH3) and orthophosphate (PO43-) concentrations, and circumneutral pH. Our research group assessed the water quality of streams within the Greenock Swamp and in the Teeswater River on October 15, 2023. Riverdale, a nearby farming community south of the Greenock, is a large source of NH3 and PO43- into the Teeswater River (Figure 1). At this sampling point, water in the river exceeded the guidelines for Canadian freshwater rivers (according to the Canadian Council of the Ministers of the Environment, CCME) and can be classified as hyper-eutrophic (CCME, 2004; CCME, 2010). However, after the river receives input from the Greenock directly or via tributaries that originate from the swamp, water quality is improved. This difference persists downstream as far as Paisley before the Teeswater River merges with the Saugeen River. For further information on the Greenock’s water filtration processes, refer to the Saugeen Conservation Watershed Report Card (2016).

Recreational activities in the Greenock support nature education and appreciation (SCA, 2021). In addition to the several kilometers of looping trails, there is a floating boardwalk through the bog adjacent to Schmidt Lake. An informational sign at Schmidt Lake on a viewing platform explains the natural history of the Greenock. In the winter, visitors can also access the trails by snowshoes or cross-country skiing, or move deeper into the swamp, which is otherwise inaccessible due to the high water levels. 

The town of Cargill hosts a museum that focuses on the historic significance of the past logging history in the Greenock and its impact on the development of this rural region (Cargill and Greenock Swamp Museum and Visitor Centre, 2023). In addition to the museum, visitors can access guided or self-guided tours in the town of Cargill about the development of the region and its connection to the Greenock Swamp (Explore the Bruce, 2023).

Public Access: Yes, fairly accessible

Surficial Geology:

The Greenock Swamp is dominated by organic soil formed from glacial advance and retreat of the Wisconsin ice sheet (Cowan., 1978; Rowell., 2012). The layer of organic soil is over 1 m thick, and it is classified as the “muck” organic soil class (Byun et al., 2022). Underneath the organic soil are thick sandy glaciolacustrine deposits from proglacial lakes (Byun et al., 2022). During periods of glacial retreat, meltwater deposited high concentrations of clay particles in the area (Cowen., 1978; Rowell., 2012). Glacial action of the Huron lobe and Georgian Bay lobe resulted in the formation of drumlin fields in the South Bruce area (Cowen., 1978; Rowell., 2012). This allowed for swamps to develop in the lower lying areas between drumlins. During our visit to the Swamp, most of the soil that we observed consisted of either poorly decayed organic matter in sites directly adjacent to Schmidt Lake or deep layers of homogenous organic matter in the birch swamp. The GSCA (1989) reported 100% of the soil to be organic matter within the birch swamp areas. Dazé et al., (2022) reported that cores under needle-leaf trees in Greenock Swamp reveal much deeper peat layers (at least 4 m) that are more homogeneous than cores under broad-leaf trees (18-60 cm); however, both swamp types in the study by Daze et al. were found to contain substantial pools of carbon across the Greenock Swamp.

Soils:

Saugeen Valley Conservation Authority

Schmidt Lake

The Drowned Lands River

Watershed Report Card (2016), Saugeen Conservation