Teacher Background –Discovering Our Blue Planet
All living things can be classified as belonging to either the plant kingdom or the animal kingdom. Vertebrates and invertebrates are the two major subdivisions of the animal kingdom. Vertebrates are animals with backbones: humans, horses, elephants, mice, fishes, etc. Invertebrates are animals without backbones: sponges, sea stars, insects, worms, jellies, etc. Ninety-five percent of all animal species are invertebrates.
There is a great assortment of colors, shapes, and sizes among invertebrates found in Alaskan waters. Lacking backbones, they have various ways of supporting their bodies. Some, such as anemones, rely on the water itself to give them shape and support.
Sponges have a support system of needle-like structures, which form an intertwining mesh. Crabs, shrimps, and beach hoppers have external skeletons, or “exoskeletons,” that must be shed as they grow. The skeletons of sea stars are composed of small plates; the plates of sea urchins and sand dollars are fused together to form a test. The soft bodies of snails and clams are encased in protective shells that increase in size as the animals grow.
Detailed information about common Alaska marine invertebrates.
Detailed information about common freshwater invertebrates, amphibians, and mammals.
Investigation 1: Backyard Water Discovery
Know your local water sources and location.
Seventy-one percent (71%) of the earth’s surface is covered by the ocean. The ocean is actually one large interconnecting system constantly mixed by winds, tides, currents, waves and upwelling. (The Seaside Naturalist p.1)
Phytoplankton don’t just live near the surface of the ocean. They are also found on mud flats along the seashore and in freshwater ponds. If you collect a jar of pond water and keep it on the windowsill for a few days, the water will turn pea-soup green as the phytoplankton bloom in the sunlight. (Sea Soup Phytoplankton by Mary Cerullo)
Phytoplankton Resources:
Phytoplankton Photos and sample pictures of phytoplankton
The initial Water Detectives ‘field trip’ is for students to become ‘aware’ of the water around them. Students need to be ‘free’ to explore and experience their new environment without specific expectations. After this initial experience, most young students will be able to focus on a ‘specific’ task.
After the first field trip, most young students will be able to focus on the ‘specific’ task of drawing from observation and then creating a map.
Investigation 2: Sea Soup
This activity will work for any water environment: saltwater, freshwater, moving water or still water. All water has some form of life.
“Sea Soup” can be used for bigger ideas and understandings as an introduction to living and non-living things in the water. It is important to know your local water features and environments and the living and non-living things that are a part of that environment. Using local human resources (e.g. USFWS, ADFG, biologists from local universities or offices, local fishermen, etc.) to find out this information is essential to making this unit appropriate for your area.
Dramatic play enhances the understanding and the centers will allow the students to explore with teacher guidance.
Local knowledge, stories, guest speakers, and the time and space for children to talk about their own ideas will support the investigation. Children need this time to construct their understanding: what do they hear in a story, how does that make sense with the Water Centers and how does it connect to their own experiences with water outside of school?
More information about the ingredients for Sea Soup:
Phytoplankton live at or near the surface of the ocean, where they can use sunlight. They need sunlight, water, and carbon dioxide to make food. Nitrogen and phosphorus are also important.
Sun – phytoplankton (like many other plants) create their own food from sunlight in a process called ‘photosynthesis’. Chlorophyll enables phytoplankton to turn the energy of the sun into sugar and oxygen.
Phytoplankton – tiny, microscopic plants that drift through the ocean on currents, waves and tides.
Zooplankton – tiny floating animals that eat phytoplankton. Zooplankton in turn may be eaten by small fishes.
Investigation 3: Living and Nonliving Things in the Water
Activity 3A: Aquatic Puzzles. Be sure to encourage vocabulary with this lesson. Showing a variety of the puzzles will be important so they understand that they are looking at how living things move, grow and change. This big idea is critical for developing understanding in this unit! Once children can successfully recognize and put puzzles together it can become an independent choice during Science Centers time in the classroom.
Students will have information about plankton and microscopic creatures from previous lessons. Photos and hands on dramatic play creatures will be useful for students to start thinking about the size of living things as they grow.
Most zooplankton can only survive near the surface of the ocean where phytoplankton they prey on can also survive. In order to stay afloat near the surface, plankton have evolved in many ways to control their position in the sea. Spikes and other projections on a plankton help to distribute the organism's weight over a large surface area, slowing its sinking. (p. 17 The Seaside Naturalist)
Online Resources:
Freshwater insect and larval stages photos
Activity 3B: Drawing From Description. This is a great lesson for students who enjoy drawing monsters and other scary things. Read the information about the pseudoscorpion, and make connections to other tiny creatures that can be found in the local environment. Having an understanding of what body parts are used for movement, eating and protection will support student questioning and understanding.
It would be helpful if children had lots of experiences with noticing body parts – legs, arms, claws and how those parts help us move or grab. Connections to class pets and/or pets at home as well as the human body are helpful to make.
Pseudoscorpion information and photos
Utah State University Extension pseudoscorpion information
Description of pseudoscorpions from Penn State College of Agricultural Sciences
Activity 3C: How Does it Look and Feel? Students need to have had lots of experiences with a variety of living and non-living things in the aquatic environment. Photos, posters, books and other resources are important to have in the room for visual support. Puppets, dramatic play, games and other resources of the aquatic environment continue this support.
Activity 3D: Our Book About Things in the Water. Students will bring their knowledge of a specific living or non-living thing to this activity. They should have an understanding of how something feels and its color, shape and size. They should have awareness or experiences with glue or glue sticks. The teacher may need to research how a living or non-living thing feels if it is not available for touching in the local area.
Activity 3E: Making A Mural. Local knowledge of aquatic environments is helpful so that you will have ideas about the tiniest plankton to larger aquatic creatures that will help to support students as they represent their understanding on a mural. It also helps to be familiar with art materials, use of brushes, paints, paper for sculpture and different ways fasteners can be used to make moving parts such as legs, antennae, claws, etc. For fingerpainting, have smocks and clean up material close at hand. Parent volunteers are valuable for this activity.
Students should be able to recall from their memory of experiences, books and other resources in the classroom. Encouraging children to describe their plan before they start in with art materials is helpful – have them describe the size, shape, and color and possibly what placement on the mural to make sure there is room.
Investigation 4: Field Trip Session
See In the Field for information about organizing and leading a field trip. It is important to have an understanding of what students may find on the field trip, and of how to collect living things. The use of local resources including publications, agencies, and people can help you to develop knowledge of your field trip site. See the resources listed for additional information about saltwater and freshwater environments.
Introduce the word “invertebrate”as meaning “softbodied animal with no bones.” Have the children find and feel their own backbones.
Discuss the habits of invertebrates. Where are invertebrates found? What are their needs? How can we help take care of them? (by being careful of them when we go to the beach, by not stepping on them, by filling in any clam holes we dig, by turning rocks back over after we look under them).
Provide students with magnifying lenses. Explain the purpose of the instrument and how to use them. Use flashlights with the magnifying lenses, if necessary for extra light. The beauty and strangeness under magnification are impressive. (Remember, however, that the light produces heat that can warm the water and the animals, so turn the light off when you’re not using it.)
Have students watch the way a jellyfish moves in a bucket of sea water. Let students touch the tentacles of an anemone and feel their stickiness (due to the discharge of stinging cells, or nematocysts). Count the legs of crabs and shrimps and feel their hard shells.
Under stress, a hermit crab will sometimes jump out of its shell. If this happens, put it quickly back in its saltwater home so that its soft abdomen will be protected. Notice how the fleshy abdomen is adapted at its tip to hang on to a shell, and observe the loss of appendages on the abdomen. Then place the empty shell next to the hermit crab, and watch how it examines the shell and inserts its abdomen.
Watch barnacles feeding with their feet. How does an amphipod move? Is the clam’s shell open just a crack to let it feed? Can you tell where a snail or limpet has been? (They will leave trails on the rocks sometimes.) Watch the tube feet of a sea star waving about. Place a sea cucumber in a pan of sea water when observing it and be careful to disturb the cucumber as little as possible because, as a protective measure, it may extrude its internal organs. The sea cucumber will grow its insides back, but that takes time and energy.
Underwater viewer instructions
An easy to make underwater viewer can be made from a coffee can (small or large). Cut out both ends of the can. Make sure the edges are smooth. File as necessary with a metal file. Use rubber bands to secure a piece of plastic wrap over one end. Students can place the covered end in the water and observe!
Visiting a Pond or Stream. Ponds can be described simply as shallow, quiet bodies of water with aquatic plants growing across them. There are millions of ponds in Alaska. If you’re lucky enough to have a pond near your school, you may want to visit it several times during the year. Go to a stream if a pond is not available.
Ask your students what they think they will find when they visit the pond r stream. Have students draw pictures of their predictions. Will they see moose, an eagle, bear, salmon?
Discuss safety; have students decide how to keep warm and dry; how to avoid falling in ponds, streams, or bogs; how to keep from getting lost. Invent some risky situations and have the students tell you how they would act to get through safely.
If the area is close enough to visit regularly, make your first visit a short exploratory one. Encourage students to use all their senses to understand the pond or stream.
- What animals live there?
- What plants can you find?
- What can you discover about the water?
- What do you notice about the area around the pond?
Remind students about the differences between invertebrates and vertebrates. What animals can they find that have backbones? (birds, frogs, muskrats, beavers, fish, people, etc.). What animals don’t have backbones? (insects, univalves, bivalves --most animals in the world are invertebrates). Students can return to the classroom with questions that will be good incentives for finding out more about wetlands.
Use various kinds of sampling equipment for your next venture. Set a minnow or blackfish trap the day before your trip (first get the permission of the Alaska Department of Fish and Game). Put on hip boots and use a sweep net to sample the water column. Have the students use kitchen strainers, large tin cans, and sweep nets to capture what they can along the pond’s edge. Collect a bucket of pond water, a bit of pond bottom, pondweed and a few critters (not big fish—they take too much oxygen) to take back for a classroom aquarium.
Investigation 5: Sharing What We Know
Be aware of the developmental levels of students, to the support needs of the speakers. You will need to be sure that the information being shared is accurate and that children are drawing the correct conclusions from their evidence. Misconceptions at this age are important to challenge with questions rather than “telling” kinds of lessons.
Think about the presentation of information and model the processes of answering questions, defending thinking and accepting appreciations of the presentation. This will assist students in understanding the expectations.
It is important to understand that children learn through questioning, exploring and exchanging ideas. Rather than gathering facts, memorizing characteristics and regurgitating from books, students are connecting to prior knowledge or notions of the world around them. The field experience is a key part of this entire unit in that children need to experience and explore the natural world to make connections with stories, non-fiction text and their own ideas and possibly correct misconceptions along the way.
One way to organize the overall communication piece is to set up a Scientific Conference for the culmination of the unit. All through the unit the teacher would call each discussion and/or investigation of information a “mini-conference” letting children know that their final information would be shared at the Scientific Conference. In this way, children would be expected to offer a piece of science information for the conference – everyone’s thinking would be important to the whole process.
