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NWP Global Registry of Apprentice Ecologists - McVicar Creek, Thunder Bay, Ontario, Canada

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McVicar Creek, Thunder Bay, Ontario, Canada
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Jubes12



Registered: September 2012
City/Town/Province: Thunder Bay, ON
Posts: 1
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McVicar Creek
A CASE STUDY
Jessie
Oct. 13th, 2011
CGU4UB - 01
Mr. Keeler


Introduction
The study of different land and habitat patterns of a river took place on October 13th at McVicar Creek, located in the north-western Ontario city of Thunder Bay, Canada. Thunder Bay’s population is approximately 122 000 with a population density of 48.2 people per square kilometre. Thunder Bay is located 52 kilometres from the United-States border and has an area of 2550 km2. The average elevation of the McVicar Creek is 204 metres (669 feet), in comparison to Lake Superior’s average elevation at 183 metres (600 feet). McVicar Creek is located in an area in which there is little fluctuation in climate and therefore does not suffer major changes through occurrences such as earthquakes and droughts (Baldwin, 2011). It is located in the subarctic climate zone, with long, cold winters and ground frost contributing to the flow of the river in the spring. See Figure 2.
McVicar Creek, similar to most of Thunder Bay’s waterways, drains into Lake Superior. The river can be classified as a meandering channel flowing in a sinuous course. Therefore vegetation and sediment accumulation is common on inside bends of meanders.
As a result of urbanization, McVicar Creek has recently begun to see some heavy development of the shoreline in the lower reaches and bank vegetation loss is imminent because of the dumping of yard wastes from Thunder Bay residents; and applications of fertilizers, herbicides and pesticides which eventually leech into the creek. The creek supports a healthy fishery, and there are ten known species existing in the creek, including wild populations of brook trout, steelhead and salmon; however, changes in the environment and disruptions threaten their survival. The North Shore Steelhead association has implemented a bank stabilization project and has begun by adding boulders, trees, and tarp around and in the creek in an attempt to keep the creek healthy (see Figure 2. Lakehead Region Conservation Authority, 2011). Macroinvertebrate refers to organisms that can be seen without the use of a microscope and benthic means that these organisms attach themselves to the bottom or substrate of rivers and streams. The benthic macroinvertebraes are a major component of the aquatic ecosystem and form an essential link between water and the fish community. An issue arises in many rivers draining into Lake Superior as many of these macroinvertebrae are sensitive to physical and chemical changes in the watercourse.
Glaciation and postglacial deposition largely account for the present landscape of Ontario. Thunder Bay is located in the Canadian Shield, and therefore the region is underlain by Precambrian rock. In the Phanerozoic age sedimentary rocks developed in marine basins, forming the Great Lakes. The majority of Ontario’s climate can be described as humid continental (Schwar, 2011), although as Thunder Bay is in close proximity to Lake Superior the climate is affected greatly by cold dry polar air from the north, and is influenced by Lake Superior’s moderating effect on the northerly flow of air; a warming effect in winter and cooling in summer.
Aim
The aim of this field study was to investigate the extent to which river morphology and human influences have altered McVicar Creek, Thunder Bay, ON. In addition, anticipate any possible, future river alterations.
Hypotheses
1. McVicar Creek follows the Bradshaw Model of a river.
The Bradshaw Model is a geographical model showing the way in which a river’s characteristics change between the upper course and lower course of a river. Discharge and occupational channel depth is predicted to increase downstream due to a greater input from the drainage basin or tributaries, and channel depth, average velocity and the load quantity of the river all increase downstream according to the Bradshaw Model. Load particle size, channel bed roughness and slope angle (gradient) decease downstream. Load particle size and channel bed roughness decreases downstream as angular pebbles become more rounded. (See Figure 4). It is also important to note that the river becomes more efficient downstream with proportionally less contact with its bed and banks.
2. Water quality worsens downstream because of urbanization. (dissolved O2, temperature, etc)
There are more residential areas located downstream along McVicar Creek and therefore it is likely that fertilisers and pesticides containing nitrates and phosphates are seeping into the river, where they enrich the water and encourage the growth of algae and other simple plants, affecting the quality of water. This growth can take over and use most of the oxygen in the water. Through the hydrological cycle unwanted substances are also able to find their way into water systems, and as Thunder Bay’s main industry is forestry, mills are a prime example of this. Traffic is also denser downstream towards the harbour and waterfront district of Thunder Bay, which produces leakages of oil and other hydrocarbons into the stream. (Lakehead Region Conservation Authority).
3. The Riparian Zone decreases, thus affecting dissolved oxygen levels, altering the river significantly downstream.
Riparian zones are the interface between land and a river or stream. It is the part of watershed immediately adjacent to the stream and is composed of moist saturated soils, water-loving plant species and their associated ecosystems (Peterson, 2011). A healthy riparian zone has four main functions; filtering sediment, stabilization banks, storing and releasing water, and recharging aquifers. Smaller riparian zones can mean more urbanization and less of a link to ecosystems through which the streams flow by providing transportation highways for wildlife and facilitating nutrient transfers.
4. Sediments downstream will consist of finer particles compared to upstream.
Flow and discharge of a river carries loose sediments towards the mouth of the river. This also causes the depth nearer the output of the river to increase. Erosion occurs upstream as the energy from running water scours the channel and removes sediment from the river bed. The higher the water velocity, the more capacity a river has for transporting sediment load. (FSC. Waugh). The bed load is then transported downstream, and unless human interference has occurred as seen in McVicar Creek, no rocks will be found downstream.
Methods of Data Collection
All measurements were collected over the course of five hours on Thursday October 13th, 2011. Seven different sites were tested for many constant factors at each location to provide evidence for the hypotheses stated above. The locations were chosen by stratified sampling; as the rivers were divided into sections and each various sample was taken, and are shown in Figure 5 (Frew 144).

Other types of sampling techniques were included as a necessary approach when planning the excursion. Random sampling was important as considerations of safety were prominent and the locations needed to be accessible primarily by bus and could not be deep enough to restrain tests. Some locations were specifically chosen (stratified sampling) because of their proximity to storm sewers. Overall stratified random sampling and random line sampling techniques were used to ensure the results were accurate. The class was divided and each group had a separate task, and the data collections of each group were later shared. GPS (Global Positioning Systems) were used in order to record each exact location and altitude where measurements were taken. A turbidity tube enabled the water quality to be tested in each location at least three times in order to calculate the mean water quality. It was important to take these measurements before others such as kick and sweep tests and channel width measurements as the movement of people in the stream disturbed the water and sediments that had settled on the bottom. An electronic pH reader allowed for easy collection of the acidity of the water, and the wetted perimeter was easily measured using measuring tape. Factors such as the discharge volume and the cross-sectional area were calculated after measurements such as velocity and channel depth were taken. The channel depth and width were found by using string, a level and a tape measure; as the creek is not a single stream but rather has many meanders, several tests were needed. (See Figure 6 and 7). There are three factors that influence the velocity of a river, the river gradient, channel roughness and channel shape. Of these, we only had the means to take into consideration two of them. The velocity is measured in metres per second, and can be tested using a flow probe; a device consisting of a vertical pole with a propeller attached to the bottom, that allows for easy testing of water velocity.
The kick and sweep test required meticulous sampling techniques; a D-shaped net was used and many sessions were needed to collect any macroinvertebrae found at each location. It was important to continuously move around the site at each location during this time to sample different habitats in the stream, such as fast moving riffles, shallow water in the inside curve of meanders, weeds and tree roots.
General qualitative observations such as signs of pollution, storm sewers, urbanization affects and the vegetation type were also observed and recorded. (See Appendix D for data).
Interpretation and Analysis
To support the first hypothesis, from the graph (Figure 11), we can surmise that the gradient decreases gradually with distance from the source as the gradient of the river is the ratio between vertical fall over horizontal distance (FSC, 2012). Although the graph does not display a consistent decrease in the gradient of the river, this is because changes in the discharge of the stream affect any changes in the rate at which the gradient decreases. The long profile of a river (shown on right) is not always portrayed by a consistent downward curve as there are many factors affected the depth over the course of a river; these are factors such as, pools and riffles, knickpoints, and load (Waugh). In the third and fourth locations there was an increase in pools as the river meandered where data was collected, creating a gentler gradient. Knickpoints occur as a result an eroded river bed and rock or sediment build-up, and were evident in the sixth location (Figure 12 and 13). The load of a river is the total mass of material transported by a river and as a consequence to different sizes of material, the gradient downstream can be affected. (Waugh 97-112). This can be seen in McVicar Creek as the gradient beocmes consistent towards the mouth of the river.

It is also important to consider that around the third, fourth and fith locations were more drainage pipes, increasing the
outflow of water.
According to the Schumm model of a river (see Figure 14), the mean flow of water (velocity) increases towards the mouth of the river. As the channel becomes deeper, wider and gains a higher discharge in its lower course, less water is in contact with the wetted perimeter allowing for the friction from the banks of the river to be reduced (FSC, 2012). The channel roughness also needs to be considered when studying velocity as the bed is more rough with pebbles and rocks upstream than downstream therefore the velocity increases.
This model supports the hypothesis that McVicar Creek follows the Bradshaw model of a river in the sense that it models a significant downstream change and we are able to easily differentiate between upstream and downstream with the data collected.
From the data collected we can also conclude that the water quality worsens towards the mouth of the river; however there were some major outliers in our data that can be explained by both experimental error and the placement of urban areas in relation to the creek. By looking at many different factors that can affect the quality of water in a body of water, the most accurate results possible were obtained. Water quality tests, dissolved oxygen and temperature of the water were all taken into account.


From these graphs, it is evident that the outliers can be found in the third and fourth locations, as the quality of the water decreases significantly. When looking at the city of Thunder Bay and its three main urban centres, an explanation as to why the quality of water decreases is easily available. Pollution can have a significant effect on the drop in water quality in the third and fourth locations as the urban areas located here alter aspects of the river measured such as the types of vegetation, the oxygen content, the acidity of the water (the pH), the temperature, and the transparency of the water or the “turbidity” (FSC, 2012). From our data collection, we know that temperature stayed consistent and therefore has not been affected by any pollution in the urban area surrounding McVicar Creek; however, the decrease in the percent of dissolved oxygen and water turbidity is evidence that such pollution exists.


In the first location where data was collected there was
much algae, demonstrating some eutrophication had occurred, perhaps because of the nearby residents and waste left in the creek, or perhaps evidence of the naturally occurring iron oxide in the water. (Refer to Appendix D for tables). Figure 15 shows an orange algae forming on the bed of the river. An explanation as to why there is such a difference in the vegetation and depth of the water (leading to the growth of algae) upstream can be found in the Bradshaw Model of a river and also in the temperature and dissolved oxygen content of the stream (Matsuda, 2011). The table in Appendix D also shows that the data collected for the dissolved oxygen was the highest of all the locations tested furthest upstream.
The riparian zones decrease in size downstream because
of the affects from urbanization, and are shown in Figure 16. Water cannot filter out pollution and sediment quickly enough without the aid of the vegetation sources. (Heritage Trust, 2011).
The final hypothesis can be proved when the images taken on October 13th are viewed (see Appendix C). The depth of the water at the source is very low and all the large rocks are above water level, however at the
mouth of the river where the water shoots out into Lake Superior, there are only pebbles found surrounding the water and they have been encased in orange netting in order to prevent them from affecting the gradient of the river as they move easily.
Conclusion
Furthermore, all the hypothesis have been proven to have some aspect of truth, and have helped gain a more thorough understanding of the entire course of McVicar Creek. The morphology of the river did change along its course from narrow to wide and from a high velocity to no flow whatsoever in various locations; these changes allow the river to stay at dynamic equilibrium.
The study could be furthered by observing any changes in the river formations after the winter months, rather than after the summer months. Another aspect of McVicar Creek that could be easily studied with the data already collected is the affect of urbanization and pollution on the macroinvertebrae living within the creek.
Although some residential and urban settings have disrupted the creek, the impacts are not severe, and as long as they remain controlled McVicar Creek should continue to thrive.
Date: September 29, 2012 Views: 7664 File size: 15.0kb, 2775.7kb : 3648 x 2736
Hours Volunteered: 12
Volunteers: 20
Authors Age & Age Range of Volunteers: 16 to 17
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