Recognize the different types of animal and plant life in the
intertidal
Consider the necessary adaptations of each animal for survival in
the intertidal
Materials:
Small objects to be placed for the unnature nature trail, e.g.
clothespin, cotton swab, popsicle stick, glue stick, colored paper,
crayons, etc. Up to 10 maximum.
Plastic paint pan insert
Clipboards, paper, pencils
Random art supplies that easily biodegrade in the water, e.g. clay,
nuts, tissue paper, etc.
Magnifying chambers
Baggies for collecting any stray seaweed to take back to press
Two way magnifying chambers for viewing small animal life
Beachcomber's Guide to intertidal marine invertebrates of Southcentral
Alaska
Dip nets
Rubber boots
Good listening ears
Preparation:
Consult the Tide Tables for low tide in the area before setting off for
the beach! Plan to visit a good, safe site for observing animal and plant
life in the intertidal. Look for sites with tide pools present at low
tide.
You may choose to use the puppet show, Life's a Beach, as an introduction
to the various animal and plant life in the intertidal zone. Fifth or
sixth grade students can perform the puppet show for their classmates.
Have objects for the unnature, nature trail ready, with a list of
"discovery" items for each group attached to a clipboard.
Procedure:
Begin by introducing the different intertidal zones. Ask students
what creates the distinctive zones - tides. Give a brief description
of the causes of tides. (Chapter four of Pacific
Seashores: A guide to intertidal ecology is an excellent
reference.) Write all possible hypotheses on the board. Demonstrate
the slow movements of tides by using the paint pan plastic insert.
First, using a hole punch, put a small hole through the side of the
insert, somewhere towards the deeper end. Position the paint pan
insert in a sink or tub, then fill with water. Students will be able
to observe the ebbing of the tide (which usually takes 6 hours!). To
demonstate tidal flooding, turn the faucet on at a tickle, and let it
fill the insert.
While the students are observing and thinking about tides, ask about
the animal and plant life that live in the intertidal. How are these lives
affected by the tides? Low and high? What sorts of adaptations would these
creatures have to have to sustain these extremes? Explain that having
adaptations means having special parts for special jobs. Can you imagine
a mussel without any threads to hold it fast to a rock? What if there
weren't any empty shells for the hermit crab to make his home? And so on.
Consider the many different adaptations of various animals and plants.
Now that the students have thought about some of the specific
adaptations, ask them the reasons why animals and plants need to adapt?
Answers should relate to locomotion, food resources, and shelter. Example:
an animal that lived in a rain cloud, what special parts would that animal
need to provide food, shelter and locomotion? List students responses on
the board.
Let the students design (in groups or individually) an animal or plant
that they will leave overnight somewhere in one of the intertidal zones.
Have materials ready and guide students if necessary. Remind students to
think of special parts for getting food, finding shelter, anchoring
themselves and their shelters, and moving within the intertidal zones.
When students are finished creating their animal or plant, they are
ready to return to the beach walk to place their creations in the intertidal
habitat. Before students return to the intertidal, help them decide which
zone they would like to place their creature. Bring creatures, clipboards and
itemized lists. Remind the students of their responsiblities at the beach,
i.e. no running, throwing or removing critters from this area. If necessary,
assign the students into groups.
If students are assigned to groups allow them to make up names for
their group. Draw a map, using landmarks to identify the
exact locations of the placement of each "unnature" creature. Pass
out the clipboards with a list of five things for them to find on each.
Items to find might be red in color, clinging to a rock, living under a rock,
the shape of a circle, rough in texture, etc. Instruct the students to leave
the animal or plant where they are (more paper could be provided for drawings
of animal or plant life). When the groups are finished finding the items on
their lists, they should return to the instructor to compare lists and to
observe the items found that were different. This will require some patience
on their part, and some running around on yours!
Point out the discoveries of your own to the student! Gather seaweed
that is lying around for pressing, if desired. Sun print paper is nice for
beach walks, students can arrange rock, shells or driftwood on it and lay it
in the sun to develop. This provides a wonderful souvenir and helps to keep
the beach intact.
Upon returning to the classroom, draw, paint or write about the
interesting creatures inhabiting the intertidal zone. Students can animate
their favorite creatures or write stories about their experiences. Journal
entrees are recommended.
Students should be allowed to return the next day to retrive their
animal or plant if it survives against the tide. Why did some creatures
survive while others were washing away? What special parts were used? What
adaptations could creatures use to better survive the harsh intertidal
environment?
