Aqua Words by gabyion


									               LESSON 1                                       affect because it’s closer to the earth than the
           The Intertidal Zone:                               sun. The pull of the moon creates a bulge in
                                                              the ocean nearest the moon (and a second
    Tides and How Creatures Survive
                                                              bulge on the opposite side of the earth from
           Kindergarten to Grade 3
                                                              centrifugal force.)

Objectives                                                    3.What does the beach look like at low tide?
•   To observe what happens with tides and                    At high tide? Show photos of the same beach
    tidal action.                                             at low tide and then at high tide. Here in the
•   To describe and act out the appearance and                northeast Pacific, the tide comes in (floods)
    behaviour of a variety of animals and                     and goes out (ebbs) twice a day.
    seaweed that live in the intertidal zone.
                                                              Solve these mysteries (from Beside the Sea,
Materials                                                     by K. Francis and G. S. Jamieson, Page 26)
Cake pan, water pitcher, sand, gravel, rocks,                 A. You build a sand castle at low tide. The
water, earth ball, photos of a beach at high and              next day you take your friends to see it and it’s
low tide, pictures of limpet, crab and clam                   gone. What happened?
(include shells if available)
                                                              B. One morning at low tide, you notice a large
Concepts                                                      clump of mussels on a wharf pile. You take
•   Tides rise and fall twice a day here.                     your little brother to see it in the afternoon and
•   Tides are caused by gravitational pull of                 it’s gone. Where is it?
    the sun and moon on the ocean.
                                                              C. One morning at low tide you leave your
•   Tidal currents can cause movement of
                                                              shoes on the beach. The next day, you go back
    objects. Heavier objects are more stable.
                                                              to find them. You do find them but they are
•   Intertidal animals have adapted to survive
                                                              100 m from where you left them. Who moved
    tidal action.
                                                              Answers: The rising tide, A. levelled the
Activities                                                    castle, B. covered the mussels and C. carried
1. How much of the earth is covered by                        the shoes along the beach.
Students stand in a circle and begin to throw                 4. Set up a beach model. Put in the sand,
an inflatable earth ball back and forth around                rocks and gravel and then pour in water.
the circle. Each time a student catches it they               A. What covers the ocean bottom?
must look at where their thumbs are and state                 A: Sand, rocks and gravel
whether they are touching land or water. As
they play, one student or the teacher can keep                B. Slowly tip pan back and forth to simulate
a record of how many times student’s thumbs                   tidal action. If there is enough time, let each
land on water and how many times they land                    student try this too. What happens?
on land. (Use blue poker chips to represent                   A: The tide causes things to shift, moves things
water and white poker chips to represent land.)               around. Note that larger heavier rocks move
Discuss why they land on water more times                     less than smaller lighter ones.
than land. Water covers more than 70% of the
earth.                                                        5. To survive tidal action:
                                                              A. If you were a creature that could move like
2. How are tides caused?                                      a crab, what would you do?
It is the combination of the gravitational pull               A: Live in a tide pool, burrow under the sand,
of the moon and sun. The moon has more                        hide under a rock.
Marine Matters Oceans Education Program                Page 1                       Curriculum 1 Lesson 1: K – Gr 3
                              The Intertidal Zone – Tides and How Creatures Survive
B. What if you were a creature that couldn’t                   •    sea anemone, sea star, whelk (foot or feet
move, like a barnacle?                                              like suction cups),
A: Attach to a rock, build a strong shell                      •    crab (hide under rocks, bury in sand)
                                                               •    barnacles (glue head to rock),
C. How do intertidal animals and plants                        •    barnacles at high tide (kick food into
protect themselves so they don’t get carried off                    your mouth with your feathery feet), and
or battered by the waves?                                      •    barnacles at low tide (close up tight).
A: They have hard shells (eg clams, crabs,
limpets); They are well-attached to large rocks               B. Complete the “Staying Put” worksheet
(eg barnacles, seaweed, limpets); They have                   where students circle the part that helps each
flexible stems (seaweed).                                     creature to stay put (eg. tube feet, suction cup-
                                                              like foot, cement, holdfast).
D. Where do you find most intertidal
creatures? Why?                                               8. How do the creatures stay moist?
A: They are around, on or under large stable                  • close shell (barnacles),
rocks because the rocks provide protection                    • close up (anemones),
from tidal action and provide a place for them
                                                              • attach tightly to rocks (limpets)
to attach. The larger the rock, the more stable
                                                              • seal off open parts where foot is with a
it is.
                                                                  “trap door” called an operculum (whelks,
                                                                  turban snails, moon snails),
E. Why is it important for some intertidal
creatures to be able to hang on tightly to one                • cling to underside of rocks (sea stars,
place?                                                            sponges, tunicates),
A: So they don’t get picked up and tossed                     • hide under rocks and seaweed
around by tidal action.                                       • (gunnels, tidepool sculpins, shore crabs),
                                                              • stay in tide pools (sculpins, sea stars,
6. Students act out being animals and plants                      hermit crabs)
in the intertidal.
A. Seaweed attached by their holdfast but able                Conclusion
to bend with the waves.                                       Review tides and staying put. Have students
B. Limpets using their strong suction cup-like                demonstrate different ways animals and plants
foot to hang onto rocks.                                      have of staying put. Have students act out
C. Crabs hiding under a rock.                                 being the “tide” as a group, moving to be high
D. Clams burrowing in the sand.                               and low tide.

Try having students act out what these plants                 Extension
and animals do at high and at low tide. Other                 Tide Zone Activity
students can also be the tide moving in and                   Divide the room into four areas using flagging
out.                                                          tape. Label each area different intertidal zones:
                                                              spray, high, middle, and low tides.
7. How do intertidal animals stay put?                        Students get a card with a creature and tide
A. If you were a small beach creature, how                    zone on it. They go to the tide zone they would
would you survive the tides?                                  be found in and act out how they are able to
i. Show picture cards of different animals and                move and stay put. They should look around
seaweed and talk about how they survive.                      them and notice the other creatures in their
ii. Talk about what they do at high and low                   zone and those in the other zones.
tide.                                                         Students can also draw or colour their creature
iii. Act out being some plants and animals:                   in the correct tide zone.
  • seaweed (flexible stalks),
Marine Matters Oceans Education Program                Page 2                       Curriculum 1 Lesson 1: K – Gr 3
                              The Intertidal Zone – Tides and How Creatures Survive

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