Know your stream
River / Stream History
Investigating Water Quality in Primary School
Investigating Stream Life
Plant and Animal Relationships
Seasonal Changes
Resources
Know
your streamWhere is it ?
Where does it collect water from ?
What natural and unnatural things affect it ?
Who draws water from it and How much ?
What runs into it from the land and through drains ?
These are a few of the basic questions we can ask about our streams
and rivers.
Check out the River Detective project.
Start a River Care
Log Book and record all the information you can find about your
local river. Where did it get its name? Are there any Maori legends
about the river? What major historic events happened near the
river? How often has it dried up or flooded and what were the
most important periods in its history? How has it changed the
local landscape? What has happened to its wetlands?
Set up a team to search
local and national newspapers and magazines for articles about
rivers and keep the clippings in the River Care Log Book. Relate
these stories to what might happen or has happened in your own
catchment.
Obtain a terrain map
of your local river catchment area. Examine the map and discuss
the areas where the river flows through natural surroundings,
agricultural areas, housing areas, and industrial areas. What
sorts of contaminants might enter the river at each of these places
and how might they affect the water quality.
Discuss water quality.
What does it mean? What different standards of water quality are
used for your river? What is the difference between water that
is OK to drink, versus water that is OK to swim in? How does our
standard of water quality affect the creatures who live in or
depend on the river for their survival.
Who is in charge of
monitoring your river? How often is it monitored and where are
the samples taken? What sorts of measurements are made and what
have the results been? Perhaps the class might invite the people
who do the measuring to discuss their methods and findings.
Investigate starting,
or joining, a community based group that wants to monitor
and improve the river near your school.
River / Stream
History - 'Ask an old timer"
The current state of
your river will be related to how it has been used in the past.
It is surprising how much useful information can be gleaned elderly
local identities who have lived in the area since they were children.
Invite one or several
to come and tell "River Tales" to the children.
If they are apprehensive say: -
"All we want to know is where you used to swim, fish and paddle a boat" and perhaps the children might ask their own questions sorted out and vetted in advance :
"What was it like before the bridge / milk factory / town sewerage plant etc were put in ? "What changes were there when they built the new housing estate ?"
"When the northern bank was still covered in bush was the river any different ?"
Two visitors together
will often bounce memories off each other. They might also have
some old photographs. Ask them to bring them along. Their photos
and stories will help build a picture of change. Perhaps they
will provide information on the frequency of flooding or what
it was like when the river was important for transport before
the roads were built. They may remember great changes when the
forest was cleared to make more farmland and the logs were floated
down stream to the mill at the estuary mouth.
Ask your guests if they
mind you recording what they tell the children.
Have the children send
some drawings or copies of stories they write from what they learnt.
Discuss how different
cultural values result in differing ways of treating the rivers.
Make a list or a poster
showing all the different ways you can think of a river. Be sure
to include the many ways we use rivers and the viewpoints of all
the many different kinds of creatures that live in and around
waterways.
Safe to Drink ?
Bring back to the classroom
two large bottles of water :
* collect one from the middle of the river / stream where the flow is greatest
(See notes on Risk Management Use a bucket on a rope or tie a line to a filling bottle weighted with a few stones)
*collect the other from the edge of the stream.
Part 1In the Classroom take 6 identical drinking glasses or clear jars.
Pour two glassfuls of each river sample and two glassfuls of cold tap water.
Label the glasses A to F with Quick Stick labels - making a note of which is which.
Ask the children to
compare the water for** smell, ** clarity and ** obvious visible
particles and to describe each type of water in their note books.
Do not drink the water or allow the children to drink it.
Ask the students to
write beside their descriptions of the three types of water which
they think would be safe to drink.
Take the glasses from
the room and change the labels for numbered labels 1 to 6
but do not label them in the same order - mix the labels up but note which is which.
Ask the students to examine the same glasses of water again for clarity and smell and to identify the original label letters of the six glasses.
In some regions the
tap water smells strongly of chlorine. Ask the students what they
think the smell is and where they might have smelled it before
(in swimming pools).
Then ask why that chemical
might be in in our drinking water.
Part 2Take dropper samples of each type of water and examine them under a low powered microscope for minute stream life that cannot be seen or seen clearly with a naked eye.
The river edge water
is often rich in microscopic organisms, especially when samples
have been taken near waterweed or river margin rushes.
Take and test samples
on a previsit to find the best area for taking samples during
the class trip to the stream.
After observing the
microscopic life ask once again why the chemical (chlorine) that
they could smell in tap water is put there.
Test the answer by adding
to each glass of the river edge water samples, either some swimming
pool treatment granules - just a couple of crystals is enough
or a couple of drops of household bleach.
What does it do to the
stream life? How is this important to drinking water and streams?
Make drawings, take
photographs or use existing drawings in books to create recognition
charts of the plants and animals observed
in preliminary surveys of the waterway,
or expected to be in your area.
Write a short biography
on each one ( best done using a standard format)
Collect and preserve
single specimens of common small species as an aid to identification
and classroom study to serve as a reference collection.
Wholesale collection of stream wildlife is contrary to the spirit
of water care. However, preserved single specimens of the common
(and therefore important) creatures can be of considerable benefit
in allowing students to observe, under low power magnification,
the remarkable adaptations of small creatures for aquatic life.
These details are frequently difficult to observe in fast moving
or disturbed live animals and study of preserved creatures prior
to live study can enhance understanding and appreciation of structure
and adaptations.
Asking students to
make detailed drawings of small creatures is a very useful discipline
for developing the skills of looking carefully and evaluating
the function of different parts and meets the requirements of
the curriculum with respect to careful observation.
One creature you may
wish to study as an indicator of stream health and as an unusual
animal with a long cultural history is the Koura,
or freshwater crayfish.
Build up a relationship
flow diagram of plants and stream creatures as a wall chart and
or as an open computer file. It should show food chains and webs
but also other dependency relationships for example :
The freshwater mussel, Hyridella menziesi,
reproduces like other bivalve molluscs by releasing eggs and sperm
into the water. The release of spawn by one shellfish when the
conditions are right usually stimulates others nearby to release
their spawn at the same time so that fertilisation is achieved.
The fertilised eggs develop into free swimming larvae that feed
and grow on microscopic plant plankton. Eventually they settle
as mussel spat - minute mussels seeking a good place to attach
to before taking up a sedentary life style as a filter feeding
bivalve.
The problem for the freshwater mussel is that it lives up stream
and water flows down stream. Spawn released by the adults and
the resultant larvae get carried down stream by the current and
are in danger of being washed out to sea. The larvae are too small
to swim against the flow but do manage to get back up stream.
The larvae have a couple of very long tentacles which they probably
use as anchor ropes to slow or halt their down stream travel by
hanging on to weed or stream bed stones. These tentacles also
help them catch hold of passing native fish which they then hitch
rides from by clipping their new shells on to the fishes fins
or gill covers. The fish swim up stream against the current and
when they have travelled far enough the mussel spat release their
hold and drop to the stream bed.
There is no food connection between these two animals but the
mussel's survival as a freshwater species is dependent on freshwater
fish.
An important benefit
of creating relationship webs is that they can draw attention
to animals that might be expected to be present but are a) really
absent b) have been overlooked
------ Real absence may help identify an environmental / water
quality problem.
------ Over looked presence may highlight a problem with sampling techniques that needs correcting to make the survey worthwhile.
Example:
Natural History of New Zealand by Nic Bishop Pub Hodder & Stoughton 1992
"Food relationships in a stream" p.97 and "The Lake Food Web" p. 90
Some animals and plants
are only present at certain times of the year therefore comparative
surveys must either be conducted at the same time of year.
The regularity of the
school year and the school timetable does allow a particular sampling
programme to be scheduled for exactly the same time each year.
With a well organised
survey, very useful data can be collected which becomes progressively
more useful as a teaching tool each year the programme is continued.
Changes or stability identified by the programme become useful
tools in monitoring the health of a stream.
A baseline record of
the changes that occur through a year is important to the identification
of species loss or recruitment and of evaluating physical variations.
If possible, the baseline
record should be built on monthly observations but this is not
often easy in a full teaching schedule.* 3 monthly sampling is
minimal for establishing a useful baseline picture and fits well
into the timetable of a four term year. It will take into account
such things as seasonal variations in temperature, rainfall and
flow rate and the life cycles of annual plants and animals.
A log book should have
a standardised format so it is easy to make comparisons from month
to month, season to season or year to year.
It should include :
- a full animal and plant list and indications of the abundance of each species
- a full list of physical conditions with columns showing :
[* At 6th and 7th Form level it is often possible to design safe and useful projects in which records are collected weekly or even daily for an intensive period. The results from these senior project studies can steadily be incorporated into an ever updated baseline data collection.]
A Field Guide to New Zealand's Lakes and Rivers Brian Parkinson and Geoffrey Cox. 1990. Random Century.
Collins Handguide to the Frogs and Reptiles of New Zealand Brian Gill, 1986. Collins
From the Mountains to the Sea Nic Bishop. 1994. Reed Books.
Freshwater Life Mobil New Zealand Nature Series. Micheal Winterbourn and Karen Mason.
Guide to the Aquatic Insects of New Zealand Bulletin of the Entomological Society Number 9. 1989.
Native Animals of New Zealand. Auckland Museum Handbook.
Natural History of New Zealand by Nic Bishop Pub Hodder & Stoughton 1992
The Dragonflies of New Zealand Richard Rowe. 1987. Auckland University Press.
Pond and Stream Post Primary Bulletin Vol.15, No.1, 1962
Upper Waitemata Harbour Catchment Study - Land and Water Management Plan Auckland Regional Authority. 1983 (11 Review documents and 9 Guideline documents describing resources, ecology and management of a large and diversely used catchment.)
Contact your local or Regional Council for educational material on water supply, treatment, or rivers.
