Joe’s Bayou
Repeated Observation
So……...
What are we measuring?
Water Quality Parameters
(measureable physical properties that
determine the health of the water.)
We will be collecting quantitative
data.
(That means data with a number in it.)
Dissolved Oxygen
Dissolved oxygen is the oxygen gas
that fits in between the water
molecules in the bayou.
Fish breathe dissolved oxygen by
absorbing it through their gills.
Colder water contains more dissolved
oxygen than warmer water.
As organisms die and decompose,
they also use up the DO in the water.
Why do we measure
DO?
Water must have an adequate
amount of dissolved oxygen to
support life.
Joe’s Bayou should have a dissolved
oxygen amount between 6.1 and 9.0
ppm (parts-per-million).
pH
pH is a measure of how acidic the water is.
The pH scale goes from 1 to 14 with 7
being neutral.
The lower the number the more acidic the
water is.
Every increase of one on the scale is
actually an increase of 10 times more acid.
A pH of 5 is 10 times more acid than a pH
of 6.
Why do we measure pH?
Most plants and animals cannot
survive in water that has a pH less
than 5. It’s too acidic.
Joe’s Bayou needs a pH between 7
and 8 to be healthy.
Turbidity
Turbidity is a measure of how clear the
water is.
Suspended solids (particles floating in the
water) can block the sun’s light from
reaching the underwater sea grasses that
baby organisms use for protection.
Suspended solids can also raise water
temperature which reduces the DO.
Why do we measure
Turbidity?
High turbidity can lower the amount of
dissolved oxygen in the water and
reduce the sea grasses that juvenile
organisms need.
A good measurement is between 0
and 15 jtu (Jackson turbidity units).
Salinity
Salinity is a measure of how much
salt is in the water.
Animals and plants require certain
salinity levels to survive. Too much or
too little salt can cause them to get
sick or die.
As salinity increases DO decreases.
As salinity decreases, DO increases.
Why do we measure salinity?
Animals and plants require certain
salinity levels to survive.
Joe’s Bayou should have a salinity
between 1 and 30 ppt (parts-perthousand).
Temperature
Temperature is a measure of the kinetic
energy of an object (how fast its particles
are moving).
Higher temperatures can increase plant
growth which is good, but when there is too
much plant growth it causes a decrease in
DO when the plants die.
The higher the temperature the less DO
because the gas particles escape from the
surface of the water.
The water heats up and cools down much
slower than the land does.
Why do we measure temperature?
Temperature has a big effect on the
amount of DO in the water
Nitrates
Nitrates are essential for plant growth
but too many nitrates is a bad thing.
Too many nitrates can cause too
much plant growth which can reduce
the amount of DO available in the
water.
Nitrates are caused by fertilizers and
animal and human wastes.
Why do we measure nitrates?
Nitrates can increase temperature,
decrease DO, and indicate pollution.
A good measurement for nitrates at
Joe’s Bayou is 0 (zero).
Phosphates
•Phosphates are also essential for plant
growth but, just like nitrates, too many
phosphates is a bad thing.
•Too many phosphates can cause too much
algal blooms (lots and lots of algae L).
•Phosphates are found in fertilizers, rocks,
and soil.
Why do we measure phosphates?
•Phosphates can increase
temperature, decrease DO, decrease
the amount of sunlight getting through
the water, and indicate pollution.
•A good measurement for phosphates
at Joe’s Bayou is 0 (zero).