This is a food web activity that I developed after my spring 2006 TREC expedition on board the USCGC Healy, for 30 days in the Bering Sea. It is a set of lessons that include setting the context with a map activity, researching the organisms in, on, and around the Bering Sea, reading an article or book on connections between the organisms and the physical environment, illustrating a cross section of the Bering Sea continental shelf, and finally, drawing conclusions in assessment questions.
Students will be able to list the biotic and abiotic components of the Bering Sea Ecosystem.
Students will be able to classify the organisms in the Bering Sea food web according to the habitat they live and feed in and to which trophic level they belong based on what they eat.
Students will understand interactions and relationships between organisms in the Bering Sea, specifically predator/prey relationships.
Students will understand how changes in climate affect organism relationships and interactions in the food web.
Teachers will need to have the following materials ready before the lesson: art supplies, index cards, copies of a map of the Bering Sea, and copies of articles and question sheets if using (sample article and question sheet attached).
Part 1 – Introducing the Bering Sea
Start by asking students where the Bering Sea is located on a map.
1. Ask a volunteer to locate it on a world map and ask how far away it is in relation to your location.
- Have students explore the Bering Sea using any online map website such as:
- Google Earth: http://www.google.com/earth/index.html
- MapQuest: http://www.mapquest.com/
- Google Maps: http://maps.google.com/
- Or, have students color in the Bering Sea on an outline map and label major islands, cities, landmarks, and political boundaries on the map.
- See Enchanted Learning website for a free printable state outline of Alaska with and without labels: http://www.enchantedlearning.com/usa/label/states/alaska/. Enchanted Learning is also a paid subscription website that includes activities for all subjects and grade levels.
- Or see an atlas in the media center or access the U.S. Department of the Interior, National Atlas for a printable map online where the teacher can use correction fluid to create their own blanks for the Bering Sea, Alaska, Siberia, St. Lawrence Island, the Bering Straight, and other desired locations: http://nationalatlas.gov
Ask students to think about the organisms that they think might live in and around the Bering Sea.
- Have students list them as a warm up/bell ringer activity and share out loud.
- Or use the Think-Pair-Share method and share out loud. (Think-Pair-Share explanation from article on cooperative learning: http://www.learnnc.org/lp/pages/4771)
- Or, make a list on the board by selecting students or calling on volunteers. Go until there are no more organisms to list. Give hints as necessary. See the activity in Part 2 of this lesson for a fairly comprehensive list of organisms in the Bering Sea shelf food web.
- See if there are disagreements about organisms on the list.
- This is a great time to discuss/review and classify the organisms by their trophic levels, or how they obtain energy (producer, consumer, herbivore, carnivore, omnivore, detritovore, decomposer, heterotroph, autotroph, etc.)
Ask students to think about the physical features (abiotic factors) of the ecosystem.
- Again, use any of the methods above (Think-Pair-Share, etc.) for eliciting prior knowledge from the group.
- If the Bering Sea is local, check a local weather/marine report for temperatures.
- If the Bering Sea is far away, find a local weather/marine report for your location and for a community near the Bering Sea and have students compare and contrast. The teacher or students can make a T-Chart (http://www.learnnc.org/reference/T+chart) or Venn Diagram (http://www.learnnc.org/reference/Venn+diagram) on the board or a poster that compares the daily temperatures, humidity, sunrise, sunset, and sea surface temperatures.
- North Pacific Ocean Theme Page, Bering Sea physical characteristics and resources: http://www.pmel.noaa.gov/np/pages/seas/bseamap.html
- Current weather conditions for most places in Alaska, NOAA, National Weather Service: http://weather.noaa.gov/weather/AK_cc_us.html
- Clickable map of current sea temperatures, NOAA, National Data Buoy Center: http://www.ndbc.noaa.gov/
Part 2 – Create Organism Cards
Have students research the following organisms/components of the Bering Sea Ecosystem:
- Whales: bowhead, gray, orca, beluga
- Polar Bears
- Large marine mammals: walrus, ice seals (bearded, ringed, ribbon, and spotted)
- Humans (native Alaskans - subsistence hunters – Yup'ik, Aleut, etc.)
- Birds: puffins, gulls, spectacled eider, kittiwake, cormorant, fulmar, petral, murre, albatross, auk, shearwater, and tern
- Fish: Bering flounder, sculpin, Arctic cod, Pacific herring, and pollock
- Crabs: king crab and snow crab
- Echinoderms: sea anemone, sea urchin, sea stars, brittle stars
- Predatory marine snails (Arctic whelk, Arctic moon snail, nudibranch)
- Algae grazing mollusks: Bering chiton
- Filter feeding mollusks: mussels – Musculus sp., nut clams (Nuculana radiata) and chalky clams (Macoma calcarea)
- Ice algae,
- Benthic infauna: polychaete worms
- These are just a few websites to begin research. The school media center may have additional books and resources.
- This can also be used as an exercise in classification and taxonomy of organisms (kingdom, phylum, class, order, family, genus, species). The Integrated Taxonomic Information System has the classification of many organisms: http://www.itis.gov/index.html
Summarize the following basic information about each organism so that it fits on one side of an index card:
- Organism name, physical appearance, habitat (be specific about location in the ocean), food source, predator/prey relationships, life cycle or other major life habits, special or unique adaptations, threatened or endangered species status.
- Can include more or less information based on individual state curriculum requirements and grade level.
- The cards should be proportional to the size of the Bering Sea Ecosystem Illustration that students will make later in the lesson.
- Students can do this in small and create one set of cards per group.
Print or draw a picture of the organism on the back of the index card.
- Can use construction paper or cut recycled folders, cereal boxes, or other firm paperboard into desired size to make the cards if index cards are not available.
Part 3 – Read for Information
- Read any of the following books or articles on Yup'ik Eskimos, organisms in the food web, and/or climate change in the Arctic. There are also many websites available to suit individual class needs with varying reading levels of essays, reports, and facts. Use the term "Bering Sea Food Web" in any search engine.
- Articles available online:
- Crisis in a Northern Sea, Scholastic, Science World, October 9, 2006, Vol. 63, No. 3: http://www.thefreelibrary.com/Crisis+in+a+northern+sea%3A+can+marine+ani... (also attached)
- Polar Ice Feels the Heat, Science News for Kids: http://www.sciencenewsforkids.org/articles/20080423/Feature1.asp
- Polar Bears in Trouble, Science News for Kids: http://www.sciencenewsforkids.org/articles/20070725/Note3.asp
- Books available for purchase on book dealer websites such as Amazon.com or bookstores:
- The Boy Who Went to Live with the Seals, Hunting Tradition in a Changing World: Yup'ik Lives in Alaska Today, Ann Fienup-Riordan, 2000, Rutgers University Press.
- In Two Worlds: A Yup'ik Eskimo Family, Aylette Jenness, 1989, Houghton Mifflin.
Part 4 – Illustrate the Ecosystem
- Have students illustrate a picture of the Bering Sea ecosystem.
- Suggest showing profile view, but other views are acceptable.
- Can have students look at pictures on web, in books in the media center, or read Organism Cards for ideas about what the environment is like.
- Can choose to have students work on individual pieces of paper or design it using the computer;
- have groups of students work together on larger pieces of chart paper or poster board;
- or make a class mural using bulletin board paper (blue works very well), a chalkboard, a whiteboard, or sidewalk chalk outside on the pavement or building.
- This is a great time to review/discuss sea floor topography and features such as: continental shelf, slope, rise, etc.
- This is also a great time to review/discuss: ocean zones and habitats such as the photic zone, open sea, pelagic, benthic, neritic, infauna locations, etc.
Part 5 – Construct a Food Web (Using a diagram to assess what was learned)
Have students cut out the Organism Pictures and arrange them on a piece of white paper or construction paper.
- Students can also illustrate their own organism pictures.
- Do not glue down yet!
- They can be arranged on the ecosystem illustration they drew in Part 3 based on where each organism lives, on a blank piece of paper, or on a wall.
Have students read the Organism Cards to determine what eats what then draw connecting arrows between the organisms.
- Don't forget cards for: detritus, sea ice, and the sun.
- More than one arrow may lead to or come from an organism.
- All of the organisms should be connected.
- Arrows are typically drawn from the prey, to the predator.
Part 6 – Drawing Conclusions (Writing assessment about what was learned)
Use the Bering Sea Ecosystem Illustration and Food Web you created to answer the following questions on a separate sheet of paper. Use complete sentences.
- Identify the longest linear food chain from producer to decomposer in your food web and list the links.
- Identify a chain of the food web where there is a terrestrial / marine connection.
- Which organisms are considered the producers and why?
- Classify the organisms in your food web:
- List 2 or more primary consumers.
- List 2 or more secondary consumers.
- Which organisms are considered the decomposers and why? What is their role in the ecosystem?
- Describe what would happen down a chain of the food web if the producers did not reproduce and were in short supply. Compare this to what happens if there isn't any ice for the algae to grow on.
- In a part of the Bering Sea just south of St. Lawrence Island, there is a very cold area of the sea that has warmed up by a few degrees. Because of this, a fish called a sculpin, has begun to increase in population in an area where it did not live before. How might the food web be affected with an increase in sculpin population?
Samantha Dassler Barlow, Durham, NC, missdassler [at] yahoo.com