The following information is based on Senior 2: Manitoba Curriculum Framework of Outcomes which itself is based on the Pan-Canadian's Common Framework of Science Learning Outcomes (K - 12). Each outcome includes a brief description of the outcome, teacher background information, suggestions for instruction, a list of the general learning outcomes (GLOs) covered and overall skills and attitudes (cluster 0 outcomes) addressed in the outcome. Each outcome also contains a page number reference to the Manitoba Education and Youth document entitled "Senior 2 Science: A Foundation for Implementation" (2003). Also, where appropriate, worksheets, activities and examples have been included.
    To download these activities and/or worksheets (
A=Activity... W=Worksheet... E=Example... ), right click on the text beside the colour button(s) for each learning outcome. Select "Save Target As" to save the exercises to your computer as Adobe PDF files. To view these files, open Adobe Acrobat Reader and open the PDF files. To download a free copy of the reader, click here.

    In this cluster, students examine the complex relationships present in ecosystems in order to further investigate issues of sustainability. The large scale cycling of elements in biogeochemical cycles and the bioaccumulation of toxins in food chains are studied. Population dynamics are examined in the context of carrying capacity and limiting factors of ecosystems. The concepts and implications of species biodiversity are explored as well. With the knowledge they have gained, students investigate how human activities affect an ecosystem and use the decision-making model to propose a course of action to enhance its sustainability.

        I. Ecosystems, Biodiversity and Food Chains
                a. ecosystems
                b. biodiversity
                c. food chains and food webs
        II. Lake Winnipeg Ecosystem
                a. history
                b. description
                c. physical dimensions and features
                d. catchment area
                e. did you know?
                f. organisms and biodiversity
                g. food chain
        III. Outcome S2-1-06: Construct and interpret graphs of population dynamics.
        IV. Outcome S2-1-04: Describe the carrying capacity of an ecosystem.
        V. Outcome S2-1-05: Investigate and discuss various limiting factors that
                                        influence population dynamics.
        VI. Outcome S2-1-07: Discuss the potential consequences of introducing new
                                        species and species extinction to an ecosystem.
        VII. Outcome S2-1-08: Observe and document a range of organisms that
                                          illustrate the biodiversity within a local or regional
        VIII. Outcome S2-1-09: Explain how the biodiversity of an ecosystem
                                          contributes to its sustainability.
        IX. Outcome S2-1-01: Illustrate and explain how carbon, nitrogen and oxygen
                                        are cycled through an ecosystem.
        X. Outcome S2-1-02: Discuss factors that may disturb biogeochemical cycles.
        XI. Outcome S2-1-03: Describe bioaccumulation and explain it's potential
                                        impact on consumers.
        XII. Outcome S2-1-10: Investigate how human activities affect an ecosystem and use
                                        the decision making model to propose a course of action to
                                        enhance its sustainability.


    An ecosystem is formed by the interactions of organisms and their physical environment. Ecosystems involve both living (biotic) and non-living (abiotic) things and the relationships between them. All parts of an ecosystem are interrelated.
   Ecosystems vary in size and can be terrestrial or aquatic or a combination of both. They are influenced by climatic conditions. That is, weather, temperature, precipitation, etc. affect ecosystems. Ecosystems are dynamic which means that they are always changing and/or fluctuating.
    Some ecosystems found in Manitoba include: freshwater, prairie, grassland, arctic, tundra and boreal forest.
Click here to view a general diagram of an ecosystem.



    According to studies, biodiversity refers to the natural variety of genes, species and ecosystems in a region. A variety or difference in species in a given area is called species biodiversity. The loss of species, habitats and ecosystems is called biodiversity loss. Biodiversity loss is one of the world's most pressing crises. An example of biodiversity loss is the extinction of species. Species (plants, animals, micro-organisms) are the building blocks of food chains and ecosystems. They develop relationships with each other and with their physical environment. The more relationships or connections the more stable the ecosystem is. When an ecosystem is stable it is called sustainable.
    Sustainability refers to the ability of an ecosystem to survive on its own. This means that the ecosystem does not require much external input to keep it running. Biodiversity loss destroys the relationships and connections between species and causes the ecosystem to become less stable and less sustainable. The fewer the number of species in an ecosystem the less sustainable it is.



    All living things depend on each other to live. In 1927, a scientist named Charles Elton created the idea of a food chain. The food chain shows how organisms use each other to survive. Thus, these organisms are linked. Food chains are complex and show the transfer of energy in an ecosystem. Many food chains linked together is called a food web. Food chains and food webs usually begin with the sun but they may or may not be complete cycles. They can end anywhere after the producer level.



    A long, long time ago, continents were covered with huge ice sheets. Then, over
12 000 years ago, as the ice sheets on North America began to melt, the water was blocked from draining into the Hudson Bay by the Laurentide Ice Sheet. Thus, a huge lake called Lake Agassiz was formed. Lake Agassiz was 285 000 square kilometers in size and covered much of Manitoba and parts of Ontario, Saskatchewan, Minnesota and North Dakota. It existed for 4 000 years and it is theorized that some of Manitoba's fish species entered through this lake.
    Then, about 7 500 to 8 000 years ago, temperatures rose and the Laurentide Ice Sheet melted. Lake Agassiz drained into Hudson Bay leaving behind many lakes such as Lake Winnipeg, Lake Winnipegosis, Lake Manitoba and Lake of the Woods.
    At first, Lake Winnipeg consisted of three separate basins. Then, about 2 500 years ago temperatures rose a few degrees and the lake took its present shape. Now Lake Winnipeg is the tenth largest freshwater lake in the world.
    Before Europeans spread over North America, the indigenous people of Canada had long been settled on the shores of the great lake. Cree, Ojibwe and Assiniboine people established villages at the mouths of the major rivers that drain into Lake Winnipeg. The lake and associated river systems became sources of food and were used for communication and trade routes. At the time of European contact, there were at least 13 communities located around the shores of Lake Winnipeg.
    In 1733, Lake Winnipeg was explored by the French Canadian explorers Pierre Gaultier de Varennes and Sieur de La Verendrye. After that, it became an important route for many explorers and traders.



    Located 217 meters above sea level, Lake Winnipeg is a shallow lake composed of two basins: a deep north basin and a shallow south basin. Lake Winnipeg is the 11th largest freshwater lake in the world. The Nelson River is the only outflow of this lake and connects the north basin to Hudson Bay.
    The eastern shoreline is comprised of marshy areas. The western lakeshore is well forested and much of Lake Winnipeg is surrounded by dense stands of elm, ash, basswood, maple, and aspen. Today, the lake is used for tourism, recreation (swimming, sport-fishing, yachting), and as a storage reservoir for hydroelectric dams. At present, over 1 000 commercial fishers use the lake as a source of income and employment.



Max. length: 436 km
Max. width: 111 km
Max. depth: 36 m
Mean depth: 12 m
Volume: 285 km³
Surface area: 23 750 kmē
Shoreline length: 1750 km
Above sea level: 217 m
Salinity: 220-560 ppm
pH: 6.8-8.8

Average temperature: 2.5°C
Dissolved oxygen: near saturation
Annual precipitation: 517 mm
Sedimentation rate: 1-5 mm/yr
Catchment area: 953 250 kmē



    Lake Winnipeg's watershed covers nearly a million square kilometers which is 40 times greater than the surface area of Lake Winnipeg. This ratio is greater than any other large lake in the world. There are approximately 3 859 000 people living in the catchment area of Lake Winnipeg which covers 3 prairie provinces and portions of the United States.



    The Kyoto Protocol calls for the reduction of greenhouse gas (C02) emission. One way of achieving emission reduction targets would be to produce low-emission hydroelectric energy. Lake Winnipeg is used as a storage reservoir to generate hydropower on the Nelson River. Also, it has the potential to remove greenhouse gases out of the atmosphere and store CO2 in the form of algal cells (organic carbon). Currently, research is being conducted to determine if Lake Winnipeg is an effective carbon sink.



    The following are specific biotic wheels made up of organisms found in Lake Winnipeg. Click on the different parts of the wheel for more details.

| Manitoba Fisheries. - Biotic Wheel | Plants Animals Protists Monerans Fungi



    Below is a diagram of a specific food chain related to the ecosystem of Lake Winnipeg.


    In Lake Winnipeg, northern pike prey upon yellow perch. Students will play a game that is based upon this predator-prey relationship in order to better understand population dynamics. They will then be asked to graph data they collect from the game and read some notes about population dynamics graphs in order to determine the type of graph they created. Next, they will complete an assignment on interpreting and describing population dynamics graphs as well as constructing graphs from population data.

    Separate the class into groups of three. Hand out one Pike and Perch Game per group. Read through the setup and rules together to ensure all students understand the game. Then, let the groups play the game and complete the assignment.

    Next, provide each student with the handout "Population Dynamics Graphs" and discuss the types of population graphs in it. Have students use the handout to identify the graph they created from the game above.


    Carrying capacity is typically expressed as the number of animals of a certain type which can be supported in an ecosystem. The carrying capacity of an ecosystem depends on three factors: 1) the amount of resources available in the ecosystem; 2) the size of the population; and 3) the amount of resources each individual is consuming. The populations of most living things tend to fluctuate naturally around a certain level. That level is the carrying capacity.

    Hand out the picture of carrying capacity to each student. As a class, brainstorm a definition for carrying capacity. Based on this definition, have the class think of some factors on which carrying capacity depends. Next, provide the students with the rest of the handout so they can check their answers and complete the assignment.


    All living things need food, water, shelter and space to survive. As long as organisms have all of these things available to them, their population will continue to grow. However, populations cannot grow forever. Some form of environmental resistance (from mother nature) will stop the population's growth. The form of resistance is called a "limiting factor". Sometimes limiting factors increase a population while other times it has the alternative effect. Students will look at different limiting factors that are classified into density independent and density dependent factors.

Density Independent Factors

    Density independent factors can affect a population at any density. For example, natural disasters, temperature, sunlight, human activities, physical characteristics and behaviours of organisms affect any and all populations regardless of their densities.

Density Dependent Factors

    Density dependent factors can only affect a population when it reaches a certain density. For example, competition, predation, disease, parasitism, crowding and stress are all factors that only affect populations when they reach a certain density.

  Provide each student with a copy of the "Limiting Factors" handout and assignment. Ask students to read about limiting factors in the "notes" section. Then, ask them to read the "Yellow Perch and Lake Winnipeg" section and identify all of the limiting factors that affect these fish. They should use the worksheet provided in the handout to classify the limiting factors as density dependent or density independent. Next, have them answer the questions provided.

  Provide each group (of 2-4 students) with a copy of the "Limiting Fish Factors" boardgame. Students will play this game and classify each limiting factor they encounter as density-dependent or density-independent. You may facilitate a class discussion to ensure students classified the limiting factors correctly.


    Many species have been introduced into Manitoba. There are many reasons why species are introduced into an ecosystem. Some of these reasons include: to help control over-grown populations, to reduce crowding, for human use (to consume or gain a profit), to increase the biodiversity of an ecosystem, and accidental release or introduction.
   The introduction of species has many effects on the ecosystem. For instance, the sustainability of the ecosystem can be increased or decreased, food chains can become enhanced or disrupted and resources can be increased or depleted.
   In 1991, rainbow smelt were found in Lake Winnipeg. Rainbow smelt are very aggressive and have the potential to affect the ecosystem and fishing industry of Lake Winnipeg in a variety of ways.
    Also, species from Manitoba are extinct or endangered. The extinction of a species may have many effects on an ecosystem. For instance, a decrease in food sources, changes in relationships between species, disrupted food chains and webs, depletion of a gene pool, loss of keystone species and the reduction of ecosystem efficiency and community productivity may be caused by species extinction.
    Recently, the Bigmouth Buffalo has been identified as a species of special concern or vulnerable in Manitoba and Canada. The extinction of Bigmouth Buffalo may have some consequences to the ecosystem to which it belongs.

    Students will learn about the potential consequences of introducing a new species to an ecosystem. Have them read about rainbow smelt and the effects of introduction into Lake Winnipeg from the handout sheet. They will also be able to make some generalizations about species introduction.

    Students will learn about the potential consequences of species extinction. Have them read about species extinction in general. Then have students conduct a search on the web to find out more about Bigmouth Buffalo and potential consequences of its extinction in order to complete the assignment. An answer key is provided.


    Field study is important to science and science education since it allows students to experience a "hands-on" component of science, conduct explorations and investigations. During this field trip students will conduct a variety of activities in order to observe and document a range of organisms in a local ecosystem. They will also study the physical and chemical components of the ecosystem.

    Read through the field trip activity and decide which activities your students will be completing. Gather the necessary supplies and materials and select an area to study. Place the students into smaller groups (depending upon number of activities to be completed) and visit the study site. Have each group complete 1 or 2 activities and record their observations. Return back to class so students can complete assignments, give presentations of their findings and compare results.


    Biodiversity is the richness and variety of life - of genes, species and ecosystems. Ecosystem sustainability is the ability of an ecosystem to maintain ecological processes over long periods of time. The biodiversity of an ecosystem contributes to its sustainability. High biodiversity means that there is a great variety of species and genes in an ecosystem. Many species and genes in an ecosystem make it easier for that ecosystem to maintain its ecological processes such as succession, population dynamics, biogeochemical cycles. Thus, high biodiversity in an ecosystem increases its sustainability.

    Click the "A" button above to download the pdf file OR, if you have power point capabilities, click here to download the power point file. This file contains the Sustainability and Biodiversity lecture. Click on the "W" button to download the pdf file. This file contains a set of Note Frames, a Test and Answer Keys. Students will complete the set of Note Frames on the lecture about biodiversity and sustainability. They will study these Note Frames and write the Test to demonstrate their mastery of this outcome during the next class.


    Ecosystems need and depend upon biogeochemical cycles. Students have already learned about the
hydrological cycle in grade 8. Now, students will learn about the carbon, nitrogen and oxygen cycles. Students will also examine how fish relate to each cycle.

    Review the hydrological cycle with the class. Separate the class into groups of three. Provide each student with a copy of the handout. Each student in the group will learn about one cycle and complete the assignment. Later, they will get back into their groups and teach each other about the cycle they researched. A quiz is included for assessment purposes.


    There are many factors that may disturb biogeochemical cycles. For instance, the overuse of fertilizers may add too much nitrogen to the environment and can disrupt the nitrogen cycle. Nitrogen fertilizer is used in agriculture to help crops grow. To help keep the nitrogen cycle balanced, farmers use a variety of farming practices. Such practices include: soil testing, crop rotation, spreading manure, spreading straw during harvest and leaving some fields as summer fallow.
    Often, excess nitrogen will leach or run-off soil and enter water systems. When there is to much nitrogen in water it may lead to algal blooms and an over-growth of water plants. This excess plant growth may have several effects on fish that live in the water. For instance, as the plants grow, they use oxygen which decreases the amount of oxygen for fish. Surface algae may block sunlight from penetrating the water. Thus, plants below the surface may not be able to perform photosynthesis and they may die. As dead plants decompose, they use oxygen and again, less oxygen is available for fish. Alternatively, an increase in vegetation may provide some species of fish with shelter and protection.

    Students will draw the watershed of Lake Winnipeg on a map and then determine how much of this watershed is used for agriculture using another map that is provided. Students will read about farming practices that help keep the nitrogen cycle balanced. Then, students will use their knowledge of the nitrogen cycle and the maps to complete questions in an assignment. Answer keys are provided.


    In the late 1960's, the government became aware that harmful substances were entering the food web. These substances are taken up by organisms and stored in their body fat. They are then passed along the food chain because they cannot be released easily or quickly. This is called bioaccumulation.
Click here for a brochure that illustrates the bioaccumulation of mercury in fish.

    Read through the entire package first and collect all necessary supplies. Provide each student with a copy of the handout that begins on page 4 of the package. Discuss bioaccumulation as a class. Explain the activity's instructions to the students. Have the students participate in the activity and then complete the following assignment.


    The Manitoba Fisheries Enhancement Initiative (FEI) was established in 1993 when Manitoba sport fishing groups and commercial fishermen indicated a willingness to pay more for their fishing license if a portion went to build fish stocks. Using this revenue the Fisheries Enhancement Initiative has funded many projects in Manitoba. These projects have aimed at strengthening fish populations, improving fish habitat or fisheries education.

    After learning about the Manitoba Fisheries Enhancement Initiative (FEI), students will use the decision-making process to develop a course of action that will help increase the sustainability of a local fish ecosystem or habitat. They will take most if not all of the necessary steps to submit an application to the FEI. If the class chooses to do so, the course of action may actually be submitted to FEI and, upon approval, be put into action. To submit a proposal, follow the steps in the "Submission Guidelines" in the "Application Form". Click here for the "Application Form".