2. Rich in plants and animals
Birds and bird habitats
Are there birds?

Investigate the habitats available for birds and small living things to make nests, find food, and rest in
the river and along the riverside.
Observe whether there are many habitats for living things at the investigation site.
There are many water birds and bird habitats (3)There are not many birds or habitats (2)There are no birds or habitats (1)- 14 -

2. Rich in plants and animals
Fish and fish habitats
Are there fish?

Fish habitats are closely related to the water environment. When there are various types of habitats,various types of fish can live there. Because finding a fish is not easy, try to find their habitats.
Ornamental fish, such as colored carps, should be excluded from your investigation.
There are many fish and their habitats (3)There are not many fish or habitats (2)There are no fish or habitats (1)- 15 -2. Rich in plants and animals
Condition of the riverbed and small organisms
Are there living things on the bottom of the river?

The conditions of the riverbed and of small organisms living there tell us about the water quality.
Observe the riverbed conditions and the types of organisms.
Sand and stones are slightly covered with algae. Insects can be found. (3)The surfaces of stones are slimy in the presence of many algae (2)The bottom of the river looks dark, and no algae or insects can be found (1)- 16 -

3. Water clarity
To know how clear and clean the water is, let’s measure the transparency and the smell of the river water.
The following are three separate indicators to investigate.
-Is the water clear?

-

Does the water smell?

-Is the water clean? *This is optional for those who are interested in this item.
ScaleReasons

Question3

2

1for yourchoice-

Is the water clear?

Transparency

Transparency ofTransparencyof 70 cm or

more than 50 cm

of less thanmore

but less than 70

50 cm

cm
-

Does the water smell?

No smellA slight smell

A very badsmell-

Is the water clean? (Measure

3 mg/l or less

COD using a simple method.)- 17 -

Between 3 mg/l

More than 5

and 5 mg/lmg/l

3. Water clarity-Transparency
Is the water clear?
Transparency is a visual parameter indicating how clear the water is. Let’s measure it using atransparency tube (clean measure). When a transparency tube is not available, you can make one
using an acrylic tube. Place a water sample in a transparency tube and put it in a place where
there is no direct sunlight. Move a disk, which has a double-lined cross-shaped mark, up anddown and stop it when the mark on the disk appears clear. The reading of the water depth in thetube is the transparency of the water.
ScaleTransparency

3

More than 70 cm

2

More than 50 cm but less than 70 cm

1

Less than 50 cm

3. Water Clarity-Smell of the water
Does the water smell?
By investigating the smell of the water, we can identify the effect of wastewater (such as dirty
industrial effluent flowing into the river). The smell of water is an index used to investigate thestate of the growth/death of bacteria, algae, and microorganisms and the runoff from livestock
farms, factories, and houses.
Place a water sample in a container and shake it. Bring your nose close to the container and sniff
it. When it is difficult to take a water sample, stand near the riverside and sniff the air. Take a noteof the smell.
Scale

Smell of the water

3No smell

2

A slight smell

1

A very bad smell- 18 -

3. Water Clarity-COD
Is the water clean?
COD (Chemical Oxygen Demand) is a parameter used to investigate the level of water pollution
by organic substances. This is optional and is for those who are interested in this item.
COD is measured using a simple method. Follow the instructions on the COD test kit (e.g.,PACKTEST, manufactured by Kyoritsu Chemical-Check Lab. Corp. or SIMPLE PACK
manufactured by Sibata Scientific Technology Ltd.). Read the instructions before starting yourmeasurements because the details of the procedures and the readings of the measured values
are different for each test kit.
ScaleCOD

3Less than 3 mg/l

2

Between 3 mg/l and 5 mg/l

1More than 5 mg/l

- 19 -4. Pleasant waterfront environment
This is an observation using your physical senses to determine whether the waterfront environment ispleasant. During the observation, think about the reasons for your choice and what is necessary toimprove the water environment.
-

Scenery (feel)-Trash (visual)-

Touching the water (touch)-

Smell of the riverside (smell)-Sound along the riverside (audial)
Scale

3

2

Beautiful

Average

Not beautiful

Question-

Are the river and its

1

environment beautiful?
-

Is trash visible?

No trash

Some trash

A lot of trash-

Do you want to touch theYes, I want toI

No, I don’t wantriver water?

touch it.

touching it.

to touch it.

What do you smell alongANoAnthe riverside?

smellWhat do you hear alongThe

pleasant

Nothe riverside?

soundofsounds-

pleasant

don’t

mind
specific

smellstheriver- 20 -unpleasantsmell
specific

Unpleasantsounds or noises

Reasons
your choicefor4. Pleasant waterfront environment
Scenery (feel)
Are the river and its environment beautiful?

Stand on the riverside and feel whether the river and its surrounding scenery are beautiful. Go to thefollowing locations to observe the river.
A place where you can observe the flow of the waterA place where you can observe the other side of the riverA place where you can observe the river from a higher position, for example, on a bridge
Beautiful (3)Average (2)Not beautiful (1)- 21 -

4. Pleasant waterfront environment
Trash (visual)
Is trash visible?

Observe the amount of waste floating on the river or being dumped along the riverside and check
whether the waterfront environment is visually pleasant.
No trash (3)Some trash (2)A lot of trash (1)- 22 -

4. Pleasant waterfront environment
Touching the water (touch)Do you want to touch the river water?

On hot days in the summer, we often feel like going into rivers or touching the water.
Do you want to touch the river water? Touch the water and feel whether it is pleasant.

I want to touch it. (3)I don’t mind touching it. (2)I don’t want to touch it. (1)- 23 -