Draw a beach profile,
showing the different zones of the beach. Be sure to do this at
low tide so you can see the structure of the beach as far out
as possible. Are there sand banks offshore? Are there sand dunes?
Are there plants that can live in the sand? How far inland does
the sand go? Are there old sand dunes now covered with forests
(or houses) behind the beach? Does a river or creek or a storm
drain enter the beach? What effect does this have on the distribution
of the sand? How deep is the sand on different parts of the beach?
Determine how beach
profiles and particle size differ between beaches exposed to heavy
waves and protected beaches.
Are there any structures
built on the beach? A rock wall? A pier? A road? How does the
structure change the distribution of the sand?
Compare old photographs
of the beach with more recent ones. Your local council might have
a series of aerial photographs of the beach over time. How has
the beach and the area around it changed over the years? Photocopy
the photographs and draw an outline of the beach and sand dunes.
What changes can you find? Have the sand dunes moved towards the
sea or inland? Have there been buildings or roads constructed?
Gradually build up
a list of undisturbed beaches, damaged beaches, and beaches that
have been improved by local effort. Perhaps your local council
already has such a list. If so, obtain a copy and discuss why
the different beaches are the way they are.
Visit a beach with
high recreational use and nearby housing. Compare what you see
there (vegetation, dune structure, erosion, sea creatures, birds)
with a visit to a beach where few people go.
When you visit a beach,
imagine what it must have looked like before there were any people
in New Zealand, perhaps a thousand years ago. Draw a picture of
what you think the beach looked like then and another showing
what the beach looks like now. If you like, draw a third showing
what you think the beach will look like in another thousand years.
Collect some sand
from different beaches (have students from other schools exchange
samples from their beach) and from different parts of the beach.
Keep accurate field notes and label the sand so you know where
it came from.
Examine the sand under a microscope or magnifying glass. Can you
find differences between the samples? What are they and how do
they relate to the origin of the sand and conditions on the beach?
Describe the sand grains, giving their size, colour, and if they
are made of rock or skeletons of living creatures.
Is your sand made from skeletons of living creatures or from rocks
or both? Drop some sand grains into a clear glass or test tube
of white vinegar. Are there bubbles of carbon dioxide rising from
the sand? Try different colours of sand grains, sorting them carefully
under a magnifier. Which ones react with the vinegar? Sand made
from rocks is made mostly of silica - just as glass is. Glass
does not react with vinegar. Sand made from skeletons is made
of calcium carbonate. What happens when vinegar comes in contact
with calcium carbonate?
Grow some pingao or spinifex
seeds. What conditions do they like best? Work with your local
council to replant the seedlings when they are old enough.
Survey the dune plants
in your area. Are any of them imported?
Are any of them endangered? What is the extent of pingao surviving
in your area?
Students research
the history of a community beach care group
established to improve sand dunes. They present a report evaluating
the impact of the group's activities.
Join or organise a
beach care group and remove imported plants,
especially if they are just getting started in your area. Remember
the dunes must be replanted right away once the imported plants
are removed.
If you live near the
coast, examine your land and garden for aggressive weeds. Remove
them and dispose of them properly, perhaps by mulching and composting.
Never put garden cuttings on dune areas. Replant with native seeds.
Ask your local Forest and Bird protection society for information
about appropriate plants for your area.
Can you identify the
succession of plants from new to old dunes? Set up a transect
to map the vegetation sequence. Map changes in height above sea
level, sand particle size, protection from wind, and changes in
plant numbers and density.
What problems must
these plants solve to be able to survive on sand dunes?
What insects can you
find on the beach and the dunes? Many of them leave tiny trails
on the sand but only come out at night. Where do they live during
the day? Look out for the little Katipo spider. It lives in old
cans, driftwood and near the base of dune plants. The female is
poisonous and can be dangerous if you pick it up. She is about
6-mm long and has a shiny black body with a bright red patch on
the rear of her abdomen.
Sandhoppers look like
insects but they are amphipods - related to shrimps. They eat
all sorts of dead material - plant and animal - and along with
the sea gulls, crabs, sand lice and snails, help rid the beach
of dying and dead creatures. Without their help, the beaches would
stink of rotting vegetation and dead animals. Try placing a small
piece of dead fish or cockle in a tide pool or on a sand flat
and quietly observe what happens.
Study the birds
that depend on the beach and help protect their nesting areas.
Design and carry out
a survey of the local community near a beach. How much do they
know about the dunes and beaches? What do they feel about the
issues related to dune protection? About exotic plants? Use of
the dunes? Community participation in maintaining and protecting
dunes?
