Situated southwest of the City of Thorold, the DeCew reservoirs are easily accessible following the Bruce Trail, only a couple of hundred metres southbound from Brock University. Comprised of two large artificial water bodies, Lake Moodie is adjoined to the north east shore of Lake Gibson. Former meadow lands atop the Niagara Escarpment were intentionally flooded in 1904 to create Lake Gibson, for its hydroelectric power generation potential. Subsequent landscape alterations included damming to form Lake Moodie and channelizing the area to improve flow to DeCew Falls generating station. Currently, the primary input to the reservoirs is water supplied from Lake Erie via the third Welland Canal, located west of the lakes. The development of shipping canal routes amongst the Great Lakes has resulted in significant ecological effects, such as the introduction of invasive species through ballast water. Additional anthropogenic activity along Niagara's Twelve Mile Creek has introduced transboundary pollution problems, which include eutrophication caused by agricultural discharges and urban runoff from the construction of Highway 406 above Lake Gibson. Coupled with uncertainties regarding climate change, we risk reshaping the lakes' ecosystems. Moreover, this environment demands further research because it serves various functions with recreational, municipal and industrial benefits. Lake Gibson for example is frequently used for recreation by local fishermen, but is also the drinking source for the city of St. Catharines. Thus significant changes to the biochemistry of the lakes could present effects upon human health. The area of the reservoirs boasts a rich heritage, having been settled by indigenous peoples, pioneered and developed by John DeCew and journeyed through by Laura Secord on her walk to warn the British of impending attack. Currently, politicians are striving to protect Lake Gibson and its surrounding environment from degradative human activity with the ambition of declaring the site a conservation reserve.

Municipality: Thorold

Local area name: City of Thorold

Other identifying names or descriptions Lake Gibson is located atop the Niagara Escarpment

Latitude and Longitude: 43.107422, -79.247954

Physical Dimensions

Lake Moodie:

Maximum Length: 2.0 km

Maximum Width: 1.0 km

Surface Area: Unknown

Lake Gibson:

Maximum Length: 5.0 km

Maximum Width: 1.0 km

Surface Area: Unknown

Elevation:

Highest Point: 185m

Lowest Point: 168m

The selected local landscape of DeCew reservoirs comprises of two man-made lakes: Moodie and Gibson. The reservoirs were created in 1904 by flooding meadow land through the Beaverdams Valley, for the purposes of storing water for use as municipal drinking water and to navigate water through penstocks at Lake Moodie down to the DeCew Falls Hydroelectric plant, where energy is generated. As indicated by the formation of the lakes, many components of this landscape are artificial, altered by anthropogenic influence. Like all freshwater ecosystems, the water bodies do not exist in isolation, they are inherently connected to a variety of surrounding land-uses that influence functions within the system. For example, the primary source of water to the lakes is channelized by the Welland Canal, which directs water from Lake Erie to the reservoirs and ultimately Lake Ontario. Moreover, Lake Gibson is traversed by highway 406 and a stretch of its shoreline borders naturalized farmland under protection of the Mel Swart Conservation Park. Notably, the urban development of Brock University is located along the north shore of Lame Moodie. Thus, defining specific boundaries for the landscape is a difficult task, however for ease of understanding, the local landscape will refer specifically to the area of the reservoirs, and a surrounding buffer zone of 200 meters to account for the presence (or absence) of riparian vegetation, built environments etc.

Map 1: Lakes Moodie and Gibson are located south of Brock University, between Short Hills Provincial Park and the Thorold Settlement.

Flora

Situated in a treasure trove of biodiversity, the DeCew Reservoirs are part of Southwestern Ontario's Carolinian Biotic Zone (Head, 2017). The ecological significance of this deciduous forest zone is paramount, for not only does it provide habitat for one third of Canada's rare and endangered species, but the ecosystem is believed to house more species than any other ecosystem in the country. Moreover, in 1990 UNESCO designated the Niagara Escarpment Biosphere Reserve, which includes Lake Moodie in its protected areas (Figure 2). Rare flora within this reserve include sassafras, black walnut and swamp white oak (Head, 2017), however, one of the most notable plant species within the local landscape is the presence of Hibiscus moscheutos, commonly known as the swamp rose-mallow (see Figure 1). This flower is especially prevalent around Lake Gibson, for it thrives in open water close to cattails – which are weedy macrophytes that inhabit the littoral shore of the lakes (Brock University and Tourism Niagara, 2012a). The swamp rose-mallow has been identified as a species of special concern under the Ontario Endangered Species Act, its total Canadian population is estimated to consist of less than 10,000 plants. As a perennial species it is slow-growing and can be overtaken by shrubs during natural succession. Whilst broad-leaved cattails facilitate growth of the swamp rose-mallow, the hybrid cattails (Typha x glauca) can overcrowd and inhibit the succession of the flower. As strong colonizers, invasive hybrid cattails spread quickly and aggressively through wetlands, particularly those high in nutrient runoff, forming large patches and dominating succession (Government of Ontario, 2019; Wisconsin Wetlands Association, 2017; Hough, 2004). The presence of the hybrid cattails restricts the distribution and abundance of the swam-rose mallow, thus the mallow occupies its Hutchinsonian realized niche in the presence of the hybrid cattails (Krebs, 2001). The concept of the realized niche applies the understanding that complete competitors cannot co-exist and species can displace eachother, ultimately limiting their capacity to occupy their fundamental and desired niche where abiotic factors are favorable to their living.

Nonetheless, native, non-invasive macrophytes are key components of both lotic and lentic systems. They could be argued to be considered autogenic engineers as they modify the environment through their very structure (Bowden et al, 2017). Hough (2004) points that biologists have long understood the role of such vegetation in recycling wastes within the system, referring to the capacity of aquatic plants to uptake large quantities of nitrates and phosphates. This is crucial because an excess of nitrogen and phosphorous within a lacustrine environment can cause eutrophication. Moreover, Lake Gibson supports a fairly large community of macrophytes, which have been identified by Placko (1999) as potential spawning habitats for fish within the lake, such as smallmouth and largemouth bass, carp and catfish.

Aquatic Organisms

Lake Gibson is popular within the region for recreational fishing. This is no surprise since up to 59 species of fish have been identified within Lake Gibson and the Twelve Mile Creek (Snukal, 2016). As aforementioned, the presence of macrophytes within the reservoirs provides essential spawning habitat for fish. Connectivity with the Twelve Mile Creek is also key because it is the only cold-water stream in the region, thus it houses Niagara's only self-sustaining trout population. Other fish species present within the lake include Northern Pike, minnows and perch species (NPCA, 2012).

Within the local landscape one of the most endangered species is the American Eel, with a recorded decline of 65% of maturing eels within the region from 1998 to 2012 (Government of Canada, 2013). The Eel has been designated 'threatened' status by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and became protected under the Ontario Endangered Species Act in 2007. COSEWIC has acknowledged that the construction of dams and human alterations to the watershed have devastated eel populations (Government of Canada, 2013). Penstocks impede upstream migration of juvenile eels when fish passes are not provided, and the turbines operating in hydroelectric dams (e.g. DeCew Falls) account for a significant mortality of eels - up to 40% - during migration downstream towards spawning grounds. The amount of water that flows through the penstock is controlled by a sluice, which is a gate that can be raised and lowered to govern the amount of water allowed to flow through. When a large discharge is allowed to pass through the penstocks in a rapid release, catastrophic macroinvertebrate drift can occur. Here substantial numbers of macroinvertebrates are washed downstream and removed from the lacustrine environment, rendering them vulnerable to a host of dangers, e.g. predation or mortality within the turbines.

Terrestrial Fauna

Whilst the Carolinian zone boasts a wealth of plant species, the ecosystem supports a dense community of fauna. Notable animal species include spotted turtles, red-backed salamanders and the white-tailed deer (Head, 2017). Moreover, the Niagara region has five designated Important Bird Areas (Brown et al, 2010). As indicated by (Figure 3), the southern reaches of Lake Moodie, and western reach of Lake Gibson are included in one of these Important Bird and Biodiversity Areas (IBAs) of Canada. All of the IBAs either extend over water bodies, or are situated adjacent to them, illustrating the significance of freshwater bodies for the breeding and migratory species of birds within the Niagara region. The DeCew Reservoirs serve specifically as feeding and sanctuary area for several bird species, including wood ducks, great blue herons, pileated woodpeckers and green-winged teals (Head, 2017). The IBA within this local landscape is ranked as nationally significant, for it provides habitat for nationally threatened species. For example, Hooded Warblers have been recognized as a nationally threatened species, however in 1993 they were discovered in the headwater forests surrounding the local landscape (IBA Canada, n.d.) Moreover, it is essential to understand the dynamic processes operating within an ecosystem, as everything is linked and related. One of the primary threats affecting this IBA designated site is the aggressive invasion of the non-native Garlic Mustard plant. The herbaceous species is allelopathic, it produces chemicals that inhibit the growth of other plants and grasses; however, its impacts do not just affect the plant community. The forests of Ontario have evolved to depend on leaf litter, which provides a layer of organic matter on the forest floor that decomposes slowly, yet when Garlic Mustard leaves die they accelerate the rate of decay of native leaf litter. Ultimately the Garlic Mustard alters the composition of the litter layer on the forest floor, which reduces habitat for ground-nesting birds and forest floor dwelling animals such as salamanders (Anderson, 2012).

Human Impacts:

The ecology of the local landscape has suffered many consequences of human activity. At the most basic level, the area was completely reshaped from a terrestrial meadowland ecosystem, to freshwater reservoirs, when humans decided to flood the valley in 1904. This constitutes a major ecological disturbance, re-structuring the ecological communities present in the landscape. Whilst there is little information available regarding the pre-flooding ecology, the lakes have been established for over 100 years so there is still a lot to infer about the ecology within this time period.

The following satellite images detail how vegetation cover has subtly increased along the shoreline and lake corridors between 2002 to present day and illustrate the expansion of an estate in Thorold, located east of Brock University, indicating increased population pressures for water and energy upon the reservoirs. Following the flooding in 1904 it can be assumed that either natural succession took place and trees began to disperse and grow in the area, or they were planted by humans. In 2009-2010 the Niagara Restoration Council teamed up with several partnering agencies and began to naturalize the environment around Lake Gibson by planting 52,000 native trees of a prairie and meadow mix (Niagara Peninsula Conservation Authority, 2011). Here humans have altered the system by physically planting trees, which has been advantageous to the ecosystem. Riparian vegetation is a major component of freshwater ecosystems for its various benefits, e.g. it provides allochthonous input into hydrological systems, roots of trees stabilize surrounding soils, and tree cover can influence local temperature/shading conditions. Additionally, the restoration of tree habitats has encouraged an increased abundance of indigenous animals, including beavers and deer.

Figure 4: Vegetation Cover 2002 to 2018

Despite this, human activities in the area have had almost deleterious impacts upon the local landscape. Figure 5 summarizes the primary threats facing lakes within the Short Hills Provincial Park and surrounding natural area. Given its close proximity to the DeCew reservoirs and the interconnected nature of freshwater ecosystems (e.g. streams feeding into the lakes), one can assume that the threats reported can be transferable to the local landscape. Studies have confirmed the severity of these threats.

Human Impacts: Pollution

It is crucial to understand the trans-boundary nature of the transport of pollutants. Many pollutants are not point-source contaminants, instead they are diffuse and can travel large distances. Regarding Lake Gibson, Placko (1999) suggests that pollutants can be transported from the Welland Canal, or even as far as Lake Erie. Lake Ontario and Lake Erie have a history of contamination and pollution by industrial chemical run off, agricultural fertilizers, untreated sewage and phosphates from laundry detergents. During the 1960s and 1970s society became increasingly concerned about the impacts of such human activity upon the ecology of the great lakes' regions and its subsequent connected water bodies (Brown et al, 2010). One of the most significant concerns was the eutrophication of the lakes, eutrophication occurs when nitrogen and phosphorous are in excess quantities, facilitating detrimental algal blooms. Lake Gibson has been classified a eutrophic lake due to its high phosphorous content. The biota of the system can indicate eutrophication, for example in Lake Gibson the macroinvertebrate community is dominated by oligochaete and chironomid species, these are specially adapted to tolerate harsh, low light and dissolved oxygen conditions (Placko, 1999). Cyanobacterial algal blooms can not only be toxic to life within the lakes, but they can also displace macrophytes and reduce the total productivity of the system by limiting light penetration.

Moreover, the Ontario Provincial Ministry of the Environment and Energy has provided Sediment Quality Guidelines which set safe levels for metals, nutrients and organic pollutants within lake sediments. This is because sediments are a primary sink of heavy metals. Sediment samples taken from Lake Gibson indicate that all metal contents exceed the Lowest Effect Level outlined by the guidelines, and in some areas the exceed the Severe Effect Level guideline (Placko, 1999). Humans have endorsed metal pollution within the local environment primarily through urban runoff, notably of copper, zinc and lead, through automotive activity and corrosion. For example in the 1970s Highway 406 was constructed, traversing Lake Gibson. Other sources of metal pollution can include mining activities, industrial waste waters and air deposition. The impacts of metal pollution on aquatic ecosystems can be deadly, for it bioaccumulates and biomagnifies up the trophic stages of the food chain. For example, perch and goldfish which are present in Lake Gibson are capable of bioaccumulating metals stored in sediments, other wildlife such as birds who feed on the fish will then be affected. Lake Gibson is a popular spot for local fishermen; so bioaccumulation of metals could affect residents who catch and eat the fish (see figure). Additionally, mammals such as skunks and meadow voles could be affected when they drink the water.

Human Impacts: Invasive Species

Water flowing from the WeIland Ship Canal and into the area near the local landscape may contain ballast water from ships. Ballast water has long held a reputation of transporting invasive species from across the globe into the great lakes' region, notably with the establishment of zebra mussels (Mills et al, 1994). Referred to as "unwelcome invaders of Ontario's waters" (Forester, 2011), Zebra mussels are highly adaptable, can spread aggressively and outcompete native populations. Where zebra mussels are concentrated in high densities they feed excessively on phytoplankton. This can affect local conditions of a water body by decreasing the turbidity of the water – essentially, they cause the water to be clearer. This increases light penetration and can influence the distribution of light-sensitive fish, such as the walleye, to inhabit deeper and darker waters. We know that zebra mussels are present in Lake Gibson and the Twelve Mile Creek because Campbell (1996) conducted a histochemical study within the area to assess zebra mussels' tolerance of elevated metal contents. Here human activity has produced a 'double whammy' impact, by increasing metal pollution, and introducing a species tolerant of it. Overall, as Wolter (2008) points out, there is a clear positive correlation between increased human activity, e.g. urbanization and the endangerment of native species with increasing invasion of non-native species.

One of the most prominent geological features of Lake Gibson is that it lays atop the Niagara Escarpment, as demonstrated by Figure 2, and Lake Moodie is situated within the Niagara Escarpment Protection Area. The Escarpment is a product of both the accumulation of sediments in a shallow tropical sea over 400 million ago, as well as glacial retreat which carved out the DeCew gorges over 11,000 years ago. Essentially the Escarpment is a ridge that extents for more than 725km through Ontario and North America, one rock face of the ridge is very steep, whilst the other is a gentle slope (Bruce Trail Conservancy, n.d.). When the lakes were formed, the water from the Beaverdams Creek plunged over the Niagara Escarpment at DeCew Falls.

Prior to human intervention the topography of the landscape was carved by glacial retreat over the Lockport Formation over 11,000 years ago. The reservoirs are also situated on the Haldimand Clay Plain (Placko, 1999), which is composed of fine-grained silts and clays deposited at the bottom of a deep glacial lake basin. Clay soils are highly impermeable, and in areas where the clay deposits are thicker than 1m, the soils are characteristic of Beverly and Toledo soils.

The impermeable characteristic of the Haldimand Clay Plain has a direct relationship with surface water hydrology. In general there are more streams and surface water bodies in the area because of the low infiltration capacity of the clay landscape. Therefore, the area experiences a high level of surface water runoff, thus making the option of flooding the land to create the reservoirs possible in the first instance. Post-glacial incisions by the tributaries of the Twelve Mile Creek upon the Haldimand Clay Plain have created an undulating physical landscape, which supports the development of regionally significant wetlands and sites of scientific interest (Drinking Water Source Protection, 2008). Moreover, the bedrock of the area was formed approximately 440 million years ago, it is believed to derive from the Ordovician to Silurian Paleozoic geological eras (Placko, 1999).

As the following figure demonstrates, Lake Moodie is surrounded by 'miscellaneous man-modified land units'. Here, Brock University was developed and opened in the 1960s. The layering of impermeable materials, such as concrete, to cover soils for development is known as soil sealing. This process is known to have considerable effects on the natural water cycle, generally it reduces actual evapotranspiration and increases and accelerates surface runoff (Wessolek, 2008). Therefore, it is expected that Lake Moodie receives additional water runoff because of its close proximity to Brock University, which is situated on its north shore.

The local landscape is primarily hydrogeological in nature, being two large reservoirs of water. However, as aforementioned, there is nothing natural about these reservoirs, they are the sheer product of human modification of the landscape. The Twelve Mile Creek watershed is well established, containing 6 sub-watersheds, including the Lake Gibson system (NPCA, 2009). Generally, the natural flow regime of the creek is stable, peak flows occur during the spring freshet, when snowfall melts, and flow declines in May after the previous increase in discharge (NPCA, 2009). Streamflow is crucial in determining the composition and productivity of freshwater communities, as macroinvertebrates and fish utilize it for habitat, drift, food sources and natural disturbance regimes (Alberti, 2008). Just as Lake Moodie has installed penstocks to barrage the north stretch of the lake, Ontario Power Generation has built four small dams along Twelve Mile Creek, these are both to control water flow and water levels for human benefit, reducing the heterogeneity of the habitat.

As urbanization unfolds, humans alter the hydrologic cycle that operates within a natural environment in many ways, for example; by consuming more water, changing land uses and surrounding vegetation cover, introducing diffuse and point-source pollutants and altering sediment composition (Alberti, 2008). In the case of the reservoirs, water levels are frequently regulated to serve the purpose of providing provincial energy and municipal water. Because demand for both water and energy can vary diurnally, weekly, monthly and yearly, cities must collect water to respond to changing peaks in demand. As the population continues to grow in the Niagara region it is likely that water and energy demand will increase, so management of flow regimes and water levels in the reservoirs may intensify.

Google Map Satellite: Lake Moodie Penstocks

The Lake Gibson system was expanded in 1947, hereby Lakes Moodie and Gibson were enlarged. To accomplish this three major channels were excavated. Firstly, an intake channel was constructed to channel water from the Third Welland Canal into the system, an equalisation channel was formed to bridge the northeast and southeast reaches of Lake Gibson, and an outflow channel from Lake Moodie to channel water to the new penstocks at DeCew Falls Plant 2 (NPCA, 2009). Moreover, the Lake Gibson system is supplied by several underground connections. The Davis culvert channels water underneath the Third Welland Canal to Lake Gibson. Beaverdams Creek also provides some input of water into the Lake Gibson system as it is diverted through the Welland Canal (NPCA, 2019). A man-made gravel berm has also been constructed adjacent to the south shore of Lake Moodie for flood mitigation function, notably to protect DeCew Road from flooding. Berms interrupt the function of natural floodplains because water is confined into a single space, reducing connectivity to surrounding floodplain features. Many berms often require frequent upkeep because they are built using soft materials, e.g. sediments and gravels that generally have a low life expectancy, thus maintaining berms to keep them in operation can be time-consuming and expensive.

Google Map Streetview: Gravel Berm

Moreover, tributaries feeding the system that are located in urban catchments have lower capacity to retain nutrients within the system. Nitrogen, carbon and phosphorous atoms complete a cycle of transformation as they move downstream, the longitudinal displacement of these atoms is termed nutrient spiraling (Newbold et al, 1981). Because the nutrient retention is low in urban catchments, spirals are longer and wider, so nutrients reach the lakes quicker, thus increased nutrient loading in lakes and reservoirs is a common challenge in lacustrine environments (Paul and Meyer, 2008). Further exacerbated by human releases of nutrients into the system, e.g. agricultural runoff, Lake Gibson has been classified as a eutrophic lake. Some areas of the lake are nutrient-saturated, and as discussed above, this can lead to the restructuring of the communities present within the freshwater ecosystem. Biological and chemical monitoring results taken by the Niagara Peninsula Conservation Authority (NPCA, 2019) indicate that most watersheds in Niagara have poor water quality. Point source pollutants such as mineral oil and greases are deposited from motoring activity along Highway 406 which traverses Lake Gibson. Placko (1999) identifies 4 areas of environmental concern in the lake, with regards to total petrol hydrocarbon (TPH) concentrations that are far beyond provincial recommended guidelines. He states that the area between Highway 406 and Merritville Highway is specifically threatened because of runoff from the roads. Both point-source contaminants and diffuse sources contribute to the pollution of Niagara's watershed, which can determine the freshwater communities present and thriving with the lakes, with less tolerant species experiencing population decline. This has knock-on effects up the food chain, all the way up to the presence of birds, which feed on the aquatic life for survival. Since the site is designated as an IBA, it is important to consider the ecological, hydrogeological and geomorphic connectivity of the landscape. Changes to one given element can fundamentally reshape the operation of an ecosystem, especially if community resilience is low.

Niagara itself has a continental climate, characterized by warm summers and cold winters. The peninsula is located north of the 43^rd latitude, and between two of the Great Lakes; Lake Ontario and Lake Erie, which buffer heat and help moderate seasonal temperatures. This mild climate favors a renowned element of the region – that is the extensive cultivations of tender fruits and grapes (Shaw, 1994).

At the micro-climate scale, the topography of the area and the influence of human settlement is extremely important. All of the principle components of climate: solar radiation, wind, precipitation and temperature are all influenced by the landscape (Hough, 2004). The most profound control of climate in the local landscape is the presence of water. Large bodies of water have a moderating effect on temperature, they warm up and cool down far more slowly than a land mass does. Additionally, because there are two large bodies of water, the process of evapotranspiration will be more significant, because water converts solar energy into latent heat, reducing air temperatures (Hough, 2004). Another key influence on micro-climate is the presence of vegetation, not only does it control solar wavelengths reflected from the ground thus influencing heat, but riparian vegetation influences local temperature conditions within the lake. Areas of the shoreline which have a high density of trees will produce a shading effect, cooling temperature conditions. The role of humans in altering a landscape's micro-climate is evidenced by the 2009-2010 efforts to naturalize the Lake Gibson corridor by planting 52,000 trees (NPCA, 2011). Again, it is worth acknowledging the connectivity of the environment, climatic controls directly influence the ecological communities present within a system. Many freshwater species have temperature tolerance thresholds, whereby their optimal habitat is above and below a given temperature range. The Twelve Mile Creek, for example, is the only cold-water stream in Niagara, supporting a self-sustaining population of trout. If temperatures were to exceed 20 to 22 degrees Celsius the species would become extremely stressed and experience population declines (Zettel, 2019). If the population of trout were to decline in the area, then the ecological community would react, for example there could be an increase in aquatic invertebrates because their main source of predation has been removed.

Human settlements can also influence micro-climate conditions. Positioned in close proximity to Brock University and the City of Thorold, the wide presence of concrete surfaces is likely to absorb thermal energy. Concrete conducts heat much faster than vegetation, so in built-up areas the temperature is likely to be warmer than in undisturbed rural sites. In big cities this is known as the Urban Heat Island Effect (Hough, 2004), however given the buffering capacity of Lakes Moodie and Gibson the effects of concrete heat retention upon the local climate are likely to be minimal. Nonetheless, human settlement is still important because impervious surfaces such as concrete encourage accelerated surface runoff of rainfall, which will direct water into the lakes. As previously mentioned, the more water present in a landscape, the more the process of evapotranspiration occurs, thus producing a cooling effect.

The graphs below demonstrate the average monthly climate conditions within the City of Thorold, which is where the lakes are located. The data is derived from a climate model drawing on weather data collected between 1982 and 2012. Generally, the climate reflects that of Niagara's continental weather pattern, with a fairly constant level of precipitation all year round, with warm summers and cold winters.

Archaeological Influences

As indicated by the First Nations Memorial situated near the south shore of the stretch where Lake Moodie adjoins Lake Gibson, the area had been settled by indigenous populations prior to the arrival of Europeans. The Lake Gibson corridor is now believed to have significant archeological potential because of the rich history of indigenous peoples in the Beaverdams area. The Twelve Mile Creek made the area a desirable location for settlement during the summer months, where next to the numerous waterways it was possible to establish camps and bases where the community could hunt, make flint tools and socialize (Head, 2017). In the winter, the Neutrals would return to more densely forested areas. It is believed that from the late 16th century to the mid-17th century, the population of neutrals in Niagara amounted to as high as 40,000. In the Beaverdams area, the First Nations communities established a series of trails, known today as the Indian trail legacy. The arterial networks they established are believed to have been too well developed to be replaced and formed a pivotal element of the townships established by European settlers. Even after the townships were first surveyed in the 1780s it was clear that settlers continued to rely upon the indigenous infrastructure (Head, 2017). Thus, Indigenous activity was crucial in laying the foundations for the earliest European settlement of Thorold. Unfortunately, the death of a Neutral Chief in 1646, hostilities surrounding the Beaver Wars (1650-1651) and the mortalities brought by European infectious diseases led to the demise of the Neutrals and many other First Nations communities in Southwest Ontario. Nonetheless, it is clear that their legacy lives on today.

Land Use History

After the arrival of European settlers, the landscape changed dramatically. Notably in the summer of 1788 John DeCew, a descendent of the French Huguenots DesCoux family, moved to Canada from America for survey work. DeCew purchased 200 acres of land in Thorold for an axe, an Indian blanket and a gold doubloon (a Spanish coin). He settled on this land building a log house at the waterfalls – known today as DeCew Falls – and constructed an oil mill for the processing of flax seeds (Robson and Hutchinson, 1994). In 1808 he built the DeCew house. At this time of course the reservoirs did not exist, however the remains of the stone structure of the DeCew house can be seen today located by the First Nations Monument, where Lakes Moodie and Gibson join together.

The landscape was extremely important during the war of 1812-1814. DeCew house was used as headquarters, and it is where Laura Secord famously walked to, to warn the British of an impending American attack. Following the war, John DeCew aimed to restore the community, he built mills, a school, a church, a blacksmith shop and houses for the mill workers. Using the streams to operate grist mills is the earliest example of how residents perceived the area's waterways as an opportunity to use the Escarpment for economic benefit. Subsequently the settlement became a recognized hamlet with the name DeCew town. However, not long after this establishment, the hamlet faced an unprecedented challenge: water shortage. A large proportion of land had been cleared to cater for the increasing settlement of the Thorold, Stamford and Pelham townships, completely altering the character of the small streams. During times of high rainfall the streams rose to flood level, but during hot summers they dwindled to only a trickle. The woods, swamps and beaver meadows that characterized the landscape prior to European settlement, had disappeared, thus the catchment had no reservoir to protect itself.

In 1896 Hamilton residents first recognized the hydroelectric potential of the 200-foot drop at DeCew falls. This would provide electrical transmission over 35 miles, to Hamilton, by installing two 1000KW generators and constructing a transmission line alongside the Grand Trunk Railway between St Catharine's and Hamilton. On November 12th, 1898 the first DeCew Falls generating plant was formally opened. At the time, this was a record and marked Canada's first venture to supply power over a long distance. Yet almost immediately after its opening, it was realized that more power would be needed, thus in 1904 significant changes to the landscape were made (Robson, 1966).

In the December 1904 the Hamilton Cataract Power Group commenced the flooding of the Beaverdams valley in order to provide the additional 50 million cubic feet of water required. The stream was then dammed to provide the two inland reservoirs that would store water for hydroelectric generation (Head, 2017). Connection to the Welland canal meant that the primary source of water to the rivers would be diverted through the canal from Lake Erie. In 1911 the two turbine generators were increased in number to eight, however substantial plans were only discussed in 1930 when the former Ontario Power Generation company - Ontario Hydro-Electric Power Commission – purchased the land. The onset of the second world war highlighted the necessity of further increasing the supply potential of the reservoir system. In 1941 plans for a second power plant were authorized, the water level of the reservoirs was increased by 4 feet and by 1947 the excavation of three major channels successfully enlarged the Lake Gibson system. This all formed the current operation we see at the reservoirs today; water is directed through an outflow channel in Lake Moodie to the new penstocks which generate electricity at the DeCew Falls Plant 2 located directly below. The landscape has changed dramatically, humans have truly put their stamp on this ecosystem, for what was once untouched meadow land has now been converted into two reservoirs with a total surface area of 13.3 hectares. Further developments beyond this included the construction of Brock University on the north shore of Lake Moodie in the 1960s and Highway 406 in the 1970s which has been built over the center of Lake Gibson.

Education and Architectural Heritage

Around Lake Gibson and Lake Moodie there are numerous heritage sites which are signposted with information describing the local area. For example, only a short walk away from Lake Moodie is Morningstar Mill at DeCew Falls. This is one of the few mills in Ontario that has been preserved to an excellent standard. The mill still exhibits all of its original equipment and operates using its original water source. As of 1994 the City of St Catharine's became responsible for the upkeep of the mill, however most work to restore the mill has be conducted by an ad hoc volunteer group from the community, The Friends of Morningstar Mill. The group has reconstructed the turbine and rebuilt the turbine shed; currently they continue to welcome more volunteers as they strive to preserve the area's rich heritage (The City of St. Catharines, 2014). Organizations such as these demonstrate how Niagara's communities stand together and remain close-knit in the face of an ever more globalizing world (Baeker and Hanna, 2009). At the mill there are several signposts describing the geology and history of the area and there are tour guides on site to educate and inform visitors about the area. Moreover, by Lake Moodie the remains of DeCew House stand, with a plaque on site, and the First Nations monument is located close by. After the house tragically burnt to the ground, the remains were converted into a historical monument in the 1950s and protected under the Ontario Heritage Act (Brock University and Tourism Niagara, 2012b). Additionally, the Mel Swart Conservation Park is located on the shore of Lake Gibson and welcomes visitors on a daily basis, encouraging learning about the ecology of the area. Once a year the park committee hosts an Earth Day where the community gathers together to participate in a tree-planting event (Mel Swart Lake Gibson Conservation Park, n.d.).

The most frequent and recently posted news regarding the reservoirs is available on the free online Niagara tabloid, NiagaraThisWeek.com. However, the largest educational affiliation is shared with Brock University. When Ontario established the provincial greenbelt, the Friends of the Greenbelt Foundation was born. This is an independent non-profit organization that has shared resources with Brock University to protect and enhance the Greenbelt. The organization posts news articles on their website to inform readers about the landscape and its history. Brock University has a collection of archives providing related information and PhD students have researched the area for their theses.

Recreational Uses

The major recreational uses of the reservoirs are hiking along the south shore of Lake Moodie and recreational fishing. The lakes are located along the Bruce Trail, a hugely popular hiking path throughout Ontario. Whilst the area is signposted as a site not to be trespassed upon, the trail is frequently used by locals and visitors, for dog walking and walking to DeCew Falls, a popular natural attraction in the area.

Lake Gibson is also popular with recreational fishermen, since it hosts over 59 species of fish. To fish at the lake you must have a license and follow regulations stated by the Ministry of Natural Resources and Forestry. However, due to the level of pollution in the lake, especially metal pollution, signs are posted around the lake to warn that pregnant women and children should not consume the fish. This is because metals such as mercury bioaccumulate in fats and lipids and can have detrimental effects on human development, such as neurological impairment. Pregnant women are advised not to eat the fish because the metals accumulate in breast milk and are therefore unsafe for babies to consume. Where there are fish, there are birds. Being designated as an IBA, the site is also popular with bird watchers, popular species to be seen are Osprey, the Peregrine Falcon, Eastern Bluebirds and the Belted Kingfishers (Snukal, 2016).

Finally, in the winter of 2017 Ontario Power Generation tried to contact local schools to warn students of the dangers of ice skating on the lakes. Due to unpredictable currents and frequently changing water levels, the lakes are considered dangerous use in general, e.g. for swimming. However, conditions in the winter of 2017 were considered to be the most hazardous yet, because of exceptionally high water levels and swirling currents making the ice less stable (Forsyth, 2017). To manage high levels, the power company was passing more water through than usual, creating a huge gap between existing ice cover and the water beneath. Thus, trespassing on the ice would be extremely dangerous. However, it was reported that children were still using the site for recreation. Consequently, extra security patrols had to be conducted to ensure the safety of locals (Forsyth, 2017).

Over time the ownership of Lakes Moodie and Gibson has changed hands, from its pre-flooding state when John DeCew owned the lands, to purchase by Hamilton Cataract Power Group, to its current ownership; the reservoirs were purchased in 1930 by Ontario Power Generation (OPG) (Brock University and Tourism Niagara, 2012c). As discussed under the land-use history section, with each successive ownership the landscape has been significantly altered and the reservoirs have been enlarged and modified for the benefit of their supply potential.

However, The DeCew Falls Water Treatment Plant and the Welland Canal is owned and operated by the Regional Municipality of Niagara, therefore, OPG leases a portion of the intake channels from the Niagara Region (Regional Municipality of Niagara, 2013). Under the lease agreement, OPG is responsible for the general upkeep, repair and maintenance of the intake channel and associated structures. In addition, in 1903 the Hamilton Cataract Group signed an agreement with the Water Works Commission of St. Catharines and the Corporation of the City of St. Catherines. Today this agreement continues to be binding under the Region of Niagara with relation to OPG. Accordingly, OPG is required to supply a minimum of 60 cubic feet per second of raw water to the Niagara Region, provide the Niagara region with an alternative water source from Lake Gibson, maintain the intake channel and the slough drains which divert overland drainage from the intake channel into Lake Gibson (Regional Municipality of Niagara, 2013). Additionally, under private ownership, public access to the site is forbidden, the site is well posted with signs that read 'no trespassing', yet enforcement appears to be minimal as the trail along Lake Moodie is frequently used.

Whilst OPG are responsible for the ownership of the site, the reservoirs and their surroundings are managed and protected by a host of actors and organizations. As demonstrated by Figure 3 some parts of Lake Moodie and Gibson are designated as IBA site ON 021. Birdlife Canada is active within this area, the program is a scientific initiative that aims to identify, conserve and monitor sites that provide essential habitat for Canada's bird populations. However, the group acknowledges that conflicting interests of ownership, notably with the prevalence of private ownership in some portions of the area, leaves the site vulnerable to land use change, at the detriment to bird populations (IBA Canada, n.d.). Likewise, in 2009-2010 the Niagara Restoration Council affiliated with numerous partnering agencies and undertook the afforestation project of planting 52,000 trees in the Lake Gibson corridor, substantially moderating the pre-existing low density riparian corridor to a higher density (Niagara Peninsula Conservation Authority, 2011).

Additionally Figure 2 indicates that Lake Moodie is also managed by the Niagara Escarpment Plan, with its borders being protected as largely as Escarpment Protected Area and some areas being Escarpment Natural Area. However, Lake Gibson is not protected by the plan. The Niagara Escarpment Plan strives to safeguard not only the geological feature of the Escarpment but its surrounding lands, for it acknowledges the connectivity of a "continuous natural environment" (Niagara Escarpment Commission, 2017: p. 75). Lake Moodie has been selected as an Escarpment Protection Area because it is a hydrologic feature which has been significantly modified by human activities. Within a protection area, the main goals of the plan are to provide a buffer to prominent Escarpment features, conserve the site's natural heritage and encourage ecological conservation and forest management (Niagara Escarpment Commission, 2017).

Parks and Recreation Department

3540 Schmon Parkway

Thorold,

L2V 4A7

Tel 9052276613

Hours: Call for Information.

Website: www.thorold.com

Social Media: City of Thorold Facebook Page: https://www.facebook.com/City.Thorold/

OR

Ontario Power Generation

Only accessibly by submitting an enquiry on the link provided.

Website: https://www.opg.com/contact-us/

Reference List

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Brock University and Tourism Niagara, (2012a) Mel Swart Lake Gibson Conservation Park, Available at: http://brocku.niagaragreenbelt.com/listings/76-par... (Accessed: 14 September 2019).

Brock University and Tourism Niagara. (2012b) DeCew House, Available at: http://brocku.niagaragreenbelt.com/listings/55-his... (Accessed 9 October 2019).

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Images

Image 1: Goodson, M. (8 September 2019) Lake Moodie Hydroelectric Penstocks (Author's own private collection).

Image 2: Tervo, R. (2014) Swamp Rose Mallow, (Ontario public collection). Available at: https://www.ontario.ca/page/swamp-rose-mallow (Accessed 12 October 2019).

Image 3: Goodson, M. (8 September 2019) Public Notice Warning the Public not to Consume Fish in Lake Gibson (Author's own private collection).

Figures

Figure 1: Ontario Natural Heritage Information Centre. (29 February 2012) Swamp Rose-mallow in Ontario, Map, no scale, Queen's Printer for Ontario. Available at: https://files.ontario.ca/environment-and-energy/sp... (Accessed 12 October 2019).

Figure 2: Geographic Information Systems (GIS) Department of the Niagara Escarpment Commission, Ministry of Natural Resources. (2017) The Niagara Escarpment Plan Map 1: Regional Municipality of Niagara, map, scale: 1:50000, Queen's Printer for Ontario. Available at: https://files.ontario.ca/appendix_-_niagara_escarp... p. 149. (Accessed 11 October 2019).

Figure 3: Bird Studies Canada (2017) Important Bird and Biodiversity Areas of Canada: Site ON021, Twelve Mile Creek Headwaters, map, no scale, IBA Program. Available at: https://www.ibacanada.ca/maps/sites/ON021.pdf (Accessed 15 September 2019).

Figure 4a: 2002 Aerial Image of Lake Moodie and Lake Gibson, Niagara Navigator, Brock University, Available at: https://maps.niagararegion.ca/Geocortex/Essentials/REST/TempFiles/8%201/2%22%20x%2011%22%20Landscape.png?guid=e594290e-c85e-43dd-bf20-a49103c2d778&contentType=image%2Fpng (Accessed 24 October 2019)

Figure 4b: 2018 Aerial Image of Lake Moodie and Lake Gibson, Niagara Navigator, Brock University, Available at: https://maps.niagararegion.ca/Geocortex/Essentials/REST/TempFiles/8%201/2%22%20x%2011%22%20Landscape.png?guid=656c4201-6792-4c9a-a199-cfd0b795fa40&contentType=image%2Fpng (Accessed 24 October 2019)

Figure 5: Jalava, J.V., Baker, J., Beriault, K., Boyko, A., Brant, A., Buck, B., Burant, C., Campbell, D., Cridland, W., Dobbyn, S., Frohlich, K., Goodridge, L., Ihrig, M., Kiers, N., Kirk, D., Lindblad, D., Van Oostrom, T., Pierrynowski, D., Porchuk, B., Robertson, P., Tanner, M.L., Thomson A. and Whelan. T. (2010). Short Hills Conservation Action Plan. Short Hills Conservation Action Planning Team and the Carolinian Canada Coalition, p. 33. Available at: https://caroliniancanada.ca/legacy/Publications/CA... (Accessed 15 September 2019).

Figure 6a: Ontario Institute of Pedology (1989) Generalized Soil Map Regional Municipality of Niagara, Ontario, Report No. 60, Scale: 1:100,000, Map Reproduction Centre, Reproduction and Distribution Division, Department of Energy, Mines and Resources, Ottawa.

Figure 6b: Ontario Institute of Pedology (1989) Generalized Soil Map Regional Municipality of Niagara, Ontario, Report No. 60, Scale: 1:100,000, Map Reproduction Centre, Reproduction and Distribution Division, Department of Energy, Mines and Resources, Ottawa.

Figure 7: Climate-Data.Org (n.d) Climate Graph // Weather by Month Thorold, Available at: https://en.climate-data.org/north-america/canada/o... (Accessed: 14 September 2019).

Figure 8: : Climate-Data.Org (n.d) Average Temperature Thorold, Available at: https://en.climate-data.org/north-america/canada/o... (Accessed: 14 September 2019).

Figures 9 and 10: Ontario Power Generation (n.d.) Water Safety Niagara Operations, Available at: https://notl.civicweb.net/document/6272 (Accessed 15 September 2019).

This Local Landscape Report was prepared by Madeleine Goodson for the Brock University course TMGT 2P94: Human Dominated Ecosystems on October 31, 2019.

All copyrights for cited material rest with the original copyright owners.