Unit 2: Sea Ice Ecology. Arctic Food Webs

Transcription

1 D Life Under the Ice Unit 2: Sea Ice Ecology Arctic Food Webs GRADE LEVEL 8-12 ACTIVITY TIME minutes LEARNING OUTCOMES Discuss ecological roles of phytoplankton and zooplankton. Discuss roles of primary producers and consumers in a food web. Describe food web interactions specific to the Arctic. Illustrate a food web. OVERVIEW In this activity students work in groups to develop an arctic marine Food Web. Groups then move through the classroom viewing each other s food webs and adding their own information. Next, complete the Great Game of Arctic Survival Lesson Plan for further handson learning about food webs. 1. Watch video & explore Interactive Food Web. 2. Brainstorm list of marine Arctic creatures. 3. Student groups create food webs. 4. Graffiti activity with food webs. 5. Interpretation of student food webs. 6. Discussion questions. THE ARCTIC SEA ICE EDUCATIONAL PACKAGE 1

2 Arctic Food Webs CONTENTS Student Flow 2 Background 3 Procedure 6 Adaptations 8 Discussion Questions 9 Extensions 11 Links 12 Interactive Sequence 12 Resources 13 Sources 16 Developers 16 STUDENT FLOW WHAT? What creatures live in a sea ice ecosystem. The predator and prey relationship between these species. WHY? Understanding food webs provides us with the knowledge to survive off the land and helps us understand our place in the world. It is very important for making informed decisions about how to manage wildlife resources and consider the impacts of development. HOW? Learn In Create Talk Watch a video showing many sea ice creature. species names in Inuktitut and traditional knowledge about them. groups, choose a species to focus on. a food web. Contribute your knowledge to others groups food webs. about your findings and figure out what it all means. Image 1 A moon jelly is attacked by polychaete marine worms. 2 THE ARCTIC SEA ICE EDUCATIONAL PACKAGE

3 D Life Under the Ice Unit II: Sea Ice Ecology BACKGROUND Cree and Inuit observe and respect a natural order of relationships connecting the largest animals to the smallest organisms. For instance, in the open-water season, Inuit dispose of sea mammal carcasses so the shrimp have the food they need and can, in turn, support the many fish, birds, and sea mammals that eat them. (McDonald, M. A., Arragutainaq, L., & Novalinga, Z.., pg.19) In the winter, sea ice is a very important physical or Abiotic component of the arctic ecosystem it impacts all of the wildlife surrounding it. The marine Arctic food web, like all other food webs, is made up of Primary Producers, Consumers and Decomposers. VOCABULARY Abiotic: Non-living elements of an ecosystem, such as weather and climate. Consumers: Organisms that prey on other creatures for food. Decomposers: Organisms that break down and recycle waste and dead organisms. Ecosystem: A community of organisms that interact with each other and their environment. Food web: A diagram that depicts energy transfer between organisms in an area. Herbivore: An organism that only eats plants. Pelagic: Relating to the open ocean. Photosynthesis: The process of turning the sun s energy into sugar as done by plants. Figure 1 PRODUCERS In the spring, water at the ice edge are teeming with life. Open water means sunlight can reach phytoplankton. Pytoplankton blooms form the base of the marine Arctic food web. Although individual phytoplankton are microscopic, the high concentration of phytoplankton can appear green to the eye because they contain chlorophyll. Photo by GRID-Arendal. On land and in the ocean, producers are plants that convert energy from the sun into sugars through photosynthesis. In the ocean, these plants are seaweeds, sea grasses and microscopic algae called Phytoplankton. In open-water, or Pelagic, ecosystems phytoplankton form the base, or first Trophic Level of the marine food web. Phytoplankton: Microscopic algae that convert sunlight into energy are an important primary producer in marine food webs. Primary Consumers: The herbivores in food webs, these animals cannot make their own food, and eat primary producers. They represent the 2nd trophic level. Primary Production: The conversion of energy from sunlight into organic compounds, such as sugars. THE ARCTIC SEA ICE EDUCATIONAL PACKAGE 3

4 Arctic Food Webs Primary Producers: Organisms such as plants and algae that make their own food by converting energy from the sun into organic compounds like sugar. Trophic Level: The position of an organism in a food web based on the distance from primary production. Zooplankton: Primary consumers in marine food webs. Small animals that graze on phytoplankton. One unusual feature of Arctic Ocean food webs is that Primary Production can only occur during a very short period of the year. Short winter days mean there is little or no sunlight to support Photosynthesis. Even as the days grow longer, thick sea ice and snow cover prevents sunlight from reaching phytoplankton in the water column. Spring blooms of phytoplankton often occur first at the ice edge. CONSUMERS Consumers include herbivores that feed on producers, predators that feed on herbivores, and predators that eat other predators. Primary Consumers Marine Arctic food web herbivores eat phytoplankton. They are commonly called zooplankton and include pelagic crustaceans like copepods. Figure 2 This common pelagic crustacean is called a copepod. Secondary Consumers Secondary consumers can be made up of multiple trophic levels from small =, krill, and prawn which generally eat zooplankton to cod and eiders which eat these smaller species and each other. Even simple food webs can have many trophic levels. Top Consumers The highest trophic level includes apex predators which are at the top of the food chain. Orcas and polar bears are two iconic examples of important arctic predators. 4 THE ARCTIC SEA ICE EDUCATIONAL PACKAGE

5 D Life Under the Ice Unit II: Sea Ice Ecology DECOMPOSERS Decomposers are another important group in every ecosystem, as they break down organic materials and make nutrients available to the primary producers. However, they do not fit into a specific trophic level because they eat dead matter from all levels. Instead they are the last step in various organic matter and nutrient cycles. Understanding the roles of different groups of organisms is integral to understanding how ecosystems work and how we are a part of them. One way we do this is by creating food web diagrams. Food web diagrams are simplified depictions of some of the relationships in an ecosystem. There is no single correct food web for any given system as each is extremely complex and it is difficult to show all the relationships possible in a given system. Figure 3 A simplified Arctic coastal food web.. FigurePhoto by GRID-Arendal. THE ARCTIC SEA ICE EDUCATIONAL PACKAGE 5

6 Arctic Food Webs PREPARATION LOAD Arctic Food Webs Interactive Sequence or individual parts from the Resources and Links section including the Unit II: Sea Ice Ecology video, Interactive Food Web & Profiles and Sea Ice Habitat Background. Load the Interactive Food Web & Profiles on one computer/tablet for each group of 3-4 students to use. PRINT (Optional) Print the Arctic Coastal Food Web Handout for each student to use as a reference or to look at later. (Optional) Print the Discussion Questions Worksheet for each student group of 3-4 students if you prefer to do the discussion questions in written format versus as a class or group orally. MATERIALS Chart paper Colored Markers Image 2 Phytoplankton / algae makes the water a greenish color are a chunk of ice due to the chlorophyll. 6 THE ARCTIC SEA ICE EDUCATIONAL PACKAGE

7 D Life Under the Ice Unit II: Sea Ice Ecology 1. Watch the Unit II: Sea Ice Ecology video to introduce/review a wide variety of the types of wildlife that live in arctic marine ecosystems. 2. Optional: Work with the Culture or Inuktitut teacher in your school to teach students traditional knowledge about the species shown in the video. What is the local Inuktitut term for each creature? (Interactive Food Web & Profiles) Which species are harvested in your community? Where? How? Share traditional stories about these species. How have their populations changed in Herring Gull Air recent memory? 3. Draw 2 horizontal lines on the board to separate the ocean, ice edge and surface, and air sections from each other or project the Sea Ice Habitat Background on your SMART Board. 4. Brainstorm a list of creatures found in the Arctic by asking students to write creatures on the board or use a cooperative or competitive approach. (Adaptations) 5. Read the Background section together as a class and/or use the Food Web Sorter SMART Notebook Activity activity. 6. Compare your class list of species with those on the Interactive Food Web & Profiles. Add any missing species and discuss how arrows in a food web follow the flow of energy rather than represent who eats whom. You can demo this using the interactive food web. 7. Divide the class into small groups (3-4 students). Each group chooses a focus species from the board around which to centre their food web. Have groups alternate between creatures that live in different spheres to ensure that a diversity of species are chosen. Suggested focus species include: Phytoplankton Zooplankton Ringed Seal Figure 4 Arctic Cod Arctic Fox Mussel Arctic Cod Arctic Char Figure 5 Eider Duck Mussel Urchin Polar Bear Eider Duck Northern Krill Ice Edge Water Urchin Snowy Owl Bowhead Whale Bowhead Whale Copepods Example of a student created food web graffiti poster.. Snowy Owl Polar Bear Arctic Fox Brainstorm arctic creatures on the board using different methods. Krill THE ARCTIC SEA ICE EDUCATIONAL PACKAGE 7

8 Arctic Food Webs Mussels Arctic Cod Thick-billed Murre Common Eider Bowhead Whale Capelin Northern Fulmar Ringed seal Polar Bear 8. Give each group a large sheet of chart paper and a marker (different colour for each group) to create their food web. Each group s food web should start with their focus species and expand outwards. 9. Allow time for the students to discuss what they saw in the video, the interactive food web and what they wrote on the board. 10. After 8-12 minutes, students leave their charts at their table and rotate to another group taking with them their group-specific coloured marker. 11. Instruct students to add their own ideas and connections in their group s colour. 12. The students will move through all the food web charts on your signal until they are back at their own. Give them 2-5 minutes at each chart and then the same back at their own to make any additions. This is a short period of time but they are not meant to cover everything - they should be making additions and connections to their focus animals, which they have discussed in much further detail while making their own chart. 13. Once the groups are done rotating, have students put up all the charts on one wall so that they can be compared. Ask student to compare how are the charts similar? How do they differ? 14. Ask the students to add bacteria into their food webs. Have the groups discuss where the bacteria should be added and their connections. Bacteria are found in the water column. They are eaten by protists (ciliates and microflagellates), other microorganisms found in the water column, which are then eaten by zooplankton. They are an important part of the carbon cycle as many bacteria take up inorganic carbon and convert it to organic carbon which can be used by other organisms that are consumers. Bacteria are also important decomposers, breaking down plant and animal tissue and returning nutrients to the environment. Some types of bacteria are found in the digestive systems of animals where they help digest some foods. In fact, bacteria are found just about anywhere you could imagine and they play many very important roles in ecosystems! 15. Use the Discussion Questions in small groups or as a class to recap the most important aspects of food webs. In particular, make sure students understand what primary producers and primary consumers are and which creatures in their food webs fill these roles. Refer back to the Food Web Sorter SMART Notebook Activity if needed. 8 THE ARCTIC SEA ICE EDUCATIONAL PACKAGE

9 D Life Under the Ice Unit II: Sea Ice Ecology ADAPTATIONS Cooperative Creature Brainstorm Challenge students to come up to the board and write down as many different marine arctic creatures as they can. To make a game out of it, give students sticky notes at their desks. Have them write a 1-2 creatures on it before sticking it on the board all at once. Have a student read out and count the number of different species. Challenge students to try again and get even more different creatures. Competitive Creature Brainstorm Split the class up into groups of 2-4. Start a timer and give all of the groups 1 minute to write down as many marine arctic creatures as they can. Ask groups to read aloud their creatures and to cross out any of their creatures that is also included in the other group s list. The team with the most unique responses is the winner. A Deeper Connection Have students attach one or more additional pieces of information to each connection in their food webs. For instance a connection between a fox and eider duck might indicate in what season they are most hunted, how the predator catches their prey, what strategies and adaptations the prey uses to avoid being caught. Students should be encouraged to use their existing knowledge where possible but they can also refer to the Predator and Prey section of each creature on the Interactive Food Web & Profiles. Find the Connection When creating food webs, give students 2 creatures separated by as many trophic levels as possible and have them find different ways to connect them in the food web. Image 3 Narwal swim through a lead in the sea ice. THE ARCTIC SEA ICE EDUCATIONAL PACKAGE 9

10 Arctic Food Webs DISCUSSION QUESTIONS 1. Where do all of the creatures in the food web ultimately get their energy? The sun. 2. Why are primary producers so important in the Arctic marine food web? Indicate the primary producers on your food web. Primary producers store light energy from the sun in chemical compounds which can be used by other organisms as energy sources. Only primary producers are capable of doing this all other organisms ultimately rely on primary producers. Thus, primary producers are important not only in Arctic food webs, but in every ecosystem in the world. In the oceans, most primary producers are phytoplankton (microscopic algae). They are particularly important in the Arctic Ocean, as other types of marine primary producers, such as seaweeds and sea grasses are uncommon. 3. What is the role of polynyas in the Arctic food web? Polynyas are areas of open water in sea ice. They are biological hot spots, because water there is some of the first to receive sunlight in spring, and therefore, the first place where the primary producers begin to grow. This in turn attracts other creatures in the food web. 4. Put humans on your food web, what do you notice and what allows humans to be different than all the other creatures? Humans exist at the top of the food web and have connections to nearly everything in the food web. We hunt polar bears, seals, whales and birds. We catch fish, collect mussels and urchins to eat. We even harvest algae! Dried kelp is used in sushi, and other algae can be a protein substitute for various diets. Human ingenuity has allowed us to make tools and processing methods in order to eat nearly everything in the food web. 5. How would the extinction of one of the species on your food web affect the other species? The extinction or decline of one species would have direct effects on predators and prey of that species. For example, if Arctic Cod were to go extinct, numbers of zooplankton might increase because Arctic Cod would not be feeding on them anymore, but Thick-billed Murre populations might decrease, as Arctic Cod are an important prey source for them. There are also many possible indirect effects if there were no more cod, and zooplankton numbers increased, then they might eat more phytoplankton than before. If there were no cod for murres to feed on, then they could possibly switch and begin eating more capelin than they did previously. Indirect effects are difficult to predict, as there are many uncertainties, especially in more complex food webs. These concepts will be explored further in the Bowhead Whale Trophic Cascade lesson. 10 THE ARCTIC SEA ICE EDUCATIONAL PACKAGE

11 D Life Under the Ice Unit II: Sea Ice Ecology 6. Why is it important for food webs to have many different connections? Food webs with lots of different connections are often more resilient. The decline or loss of one species can sometimes be compensated for by other species in the food web, so that the strength of indirect effects is moderated. For example, if Thick-billed Murres feed on both Arctic Cod and Capelin, if the cod is scarce in one year, murres can rely more on capelin. 7. What would be the downside of having a very simplified food web? In a very simplified food web, the decline or loss of one species can have a very large impact on a food web. If a predator feeds only on one prey species, it will be very strongly affected if its prey declines or disappears. 8. Which creatures in your food web are hunted in your community? Have your eaten any? Which? Image 4 A northern fulmar soars across calm arctic waters. Image 7 White in the winter, arctic fox turn brown in the summer to match their surroundings. Image 6 Copepods are herbivores that eat plankton. Photo by Uwe Kils. Image 5 A snowy owl looks for dinner. THE ARCTIC SEA ICE EDUCATIONAL PACKAGE 11

12 Arctic Food Webs EXTENSIONS The food webs developed in this activity can be used in several future lesson plans in this educational package. Based on the food webs that were created by the class, each student could make their own version which they can add to throughout future activities. To make it easy, photocopy or scan each student s original food web and then file it somewhere safe. Students can then make additions to their food web on the copies, using a different one for each lesson plan. After several versions of the food webs have been developed, students could then compare these to their original food webs. Bowhead Whale Lesson Plan In the Bowhead Whale Trophic Cascade Lesson Plan, the food webs will be used to explore ecosystem dynamics in the Arctic Ocean with and without bowhead whales. LINKS Unit II: Sea Ice Ecology video From majestic narwhals swimming along a crack in the ice to mighty walrus basking on the spring ice, this short video montage shows many different creatures that live in the Arctic marine ecosystems. Interactive Food Web & Profiles Access profiles of arctic marine wildlife and see interactive food web connections between species. Image 8 Orcas trapped in a polynya. If they don t escape soon, the polynya will close and they will run out of air. Photo by Davidee and Anna Weetaluktuk. 12 THE ARCTIC SEA ICE EDUCATIONAL PACKAGE

13 D Life Under the Ice Unit II: Sea Ice Ecology INTERACTIVE SEQUENCE Sequences combine together many different media resources such as maps, videos, photos and interactive content into a single presentation that can stepped through one frame at a time. Arctic Food Webs Interactive Sequence This interactive sequences provides video of key arctic wildlife species, images of their polynya habitat and easy access to the interactive food web. 1. Sea Ice Habitat Background 2. Coastal Arctic Food Web 3. Sea Ice Ecology Video 4. Polynya Satellite Map 5. Street View of an Arctic Fox 6. Interactive Food Web Image 9 A school of capelin crowds the ocean. THE ARCTIC SEA ICE EDUCATIONAL PACKAGE 13

14 Arctic Food Webs RESOURCES INCLUDED IN THIS DOCUMENT Sea Ice Habitat Background Water color painting of a sea ice habitat that is also used in the Interactive Food Web. Use this with your SMART Board when brainstorming your list of Arctic wildlife. It is also available in the Interactive sequence Arctic Coastal Food Web Handout A simplified illustrated food web created by GRID Arendal. Discussion Questions Worksheet If you would prefer to have students answer the discussion questions in writing rather than as a group or class discussion. AVAILABLE ON LESSON PLAN WEB PAGE The following resources are available on the Arctic Food Webs Lesson Plan web page. Food Web Sorter SMART Notebook Activity Smart Notebook file which can be used to explain basic trophic levels. Student can come up to the board and drag the creature icons to the correct location. Image 10 An arctic cod. Image 11 Comb Jelly 14 THE ARCTIC SEA ICE EDUCATIONAL PACKAGE

15 Long-term Arctic Food Monitoring Webs SEA ICE HABITAT BACKGROUND Air Ice Edge Water RESOURCE THE ARCTIC SEA ICE EDUCATIONAL PACKAGE 15

16 Arctic Food Webs ARCTIC COASTAL FOOD WEB HANDOUT 16 THE ARCTIC SEA ICE EDUCATIONAL PACKAGE RESOURCE

17 Long-term Arctic Food Monitoring Webs DISCUSSION QUESTIONS WORKSHEET 1. Where do all of the creatures in the food web ultimately get their energy? 2. Why are primary producers so important in the Arctic marine food web? Indicate the primary producers on your food web. 3. What is the role of polynyas in the Arctic food web? 4. Put humans on your food web, what do you notice and what allows humans to be different than all the other creatures? 5. How would the extinction of one of the species on your food web affect the other species? 6. Why is it important for food webs to have many different connections? 7. What would be the downside of having a very simplified food web? 8. Which creatures in your food web are hunted in your community? Have your tasted any? RESOURCE THE ARCTIC SEA ICE EDUCATIONAL PACKAGE 17

18 Arctic Food Webs SOURCES IMAGES GRID-Arendal Images courtesy of GRED-Arendal are used for educational purposes. Simone DesRoches Water color paintings of arctic wildlife by Simone were created for the Interactive Food Web. Davidee and Anna Weetaluktuk Orca video and photo used with permission. Uwe Kils Photo of a copepod used under creative commons licence. CC BY-SA 3.0: Source: REFERENCES McDonald, M. A., Arragutainaq, L., & Novalinga, Z. (1997). Voices from the bay: Traditional ecological knowledge of Inuit and Cree in the Hudson Bay bioregion. Ottawa, Ont.: Canadian Arctic Resources Committee. DEVELOPERS PRIMARY DEVELOPER Simone DesRoches and Rian Dickson CONTRIBUTORS Jackie Kidd Misha Warbanski Evan Warner CITATION Dickson, R., & DesRoches, S. (2016). Arctic Food Webs. In Heath, J. P., & Warner, E. W. P. (Ed.), The Arctic Sea Ice Educational Package. The Arctic Eider Society, St John s, NL. Retrieved from arcticeider.com/en/lesson-plan/afw 18 THE ARCTIC SEA ICE EDUCATIONAL PACKAGE