Julie C.
Chemistry Project Narrative
Natural and cultural history of Piney-Z/ Lake
Lafayette
Piney-Z is part of the chain of Lafayette lakes.
Manmade dames throughout the Piney-Z lake stop the water’s
natural flow and act as banks for fishers and sight-seers. The
water is fairly clear and animal life is present. During our adventures
we were lucky enough to see two big alligators and even held a
baby one. Many birds sang their melodies while we walked down
the trails. Although our hikes were usually easy going and relaxing,
we made sure to keep on the look out for snakes, water holes and
the infamous poison ivy. Poison ivy is a problem all over the
area and grows in abundance along with pine tress, ferns and other
plant life. When rain falls at Piney-Z it washes away the dirt
paths (and sometimes ditches) and leaves large water puddles.
Holes were also left by illegal artifact diggers. There are Indian
artifacts scattered throughout the Piney-Z property.
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Piney-Z sits over the Floridian aquifer. There
is a sinkhole in the far corner of Piney-Z. It is important that
the lake is not polluted because is the water seeps through the
rock into the aquifer and it will contaminate our drinking water.
The sink whole is part of Piney-Z’s karst topography ( the
visible structure formed in rock [like a cave] on the top of the
ground).
In the past Piney-Z was a free flowing stream. In 1995, it was
dammed up and turned into a lake. This caused the bottom to fill
much quicker and created a lake that needed to be “scraped
out” ever so often. The lake has recently been mowed to
control the aquatic plants growth. Eutrophication, a process where
phosphates that are in fertilizers and nearby soils run into the
lake through runoff or eroded soil and stimulate aquatic growth,
can cause mayor problems. If mankind continues to build on the
property surrounding Piney-Z and fertilize their yards it will
cause more runoff with high concentrations of phosphorus. This
will cause rapid and uncontrollable plant growth in the nearby
lake and suffocate natural life. It will also increase the amount
of algae which will need to be scraped out sooner. The algae may
even go into the aquifer to travel and plant itself miles downstream.
Mankind has drastically effected the Piney-Z lake. If we are not
careful the property will be ruined.
Water Quality
Dissolved Oxygen
Oxygen in the air the diffuses into water from movement. A dissolved
oxygen test measures the amount of oxygen dissolved in water.
The total oxygen level should not get too high because it is harmful
to aquatic life. For example, fish may get gas bubble disease.
It should also not get too low. DO levels below 5.0mg/L put stress
on the water’s life.
pH
pH is a measure of the nature of a solution (whether it is acidic
or basic). Levels ranging from 6.0 to 9.0 provide protection for
the freshwater fish. The pH level is useful when determining if
elements like iron, aluminum, ammonia, or mercury that mixed into
freshwater through runoff water have toxic effects.
Temperature
Reasonable temperatures for freshwater habitats are determined
by the type of water (I.e. low streams vs. mountain streams, lakes,
rivers). The location of the water also plays a role. If the temperature
is too high and the fish are not used to it it can kill them because
higher temperatures reduced the amount of available oxygen.
Nitrates
Nitrogen, which is found in air and is a major component of protein,
is one of the most abundant elements. When bacteria is water convert
from nitrites (NO2-) to nitrates (NO3-) it can cause oxygen depletion;
consequently organism depending of that oxygen will die. Nitrogen
comes into the water through wastes, septic tanks, and discharges
from car exhaust.
Phosphates
Phosphates are formed from the element phosphorous. They wash
from nearby soil into freshwater with rainfall and stimulate the
growth of plankton and aquatic plants. Some phosphates are good
because they create food that fish eat; however, to much will
create rapid uncontrollable plant growth that chokes out other
plant and animal life. This is called eutrophication or over-fertilization.
Turbidity
Turbidity measures the degree to which light traveling through
water is suspended because of living organisms (or the degree
that light it choked out due to algae or muck). The higher the
measure, the murkier the water is. High concentration of particles
causes less light to penetrate through the water and causes lakes
to fill more quickly. As the lakes fill up it chokes out life
on the its bottom.
During our visits to Piney-Z we measured DO, pH,
and temperature. To measure the DO we used a special kit (sometimes
checking it with an additional kit). After retrieving a sample
of water from the area we wished to test, we tested the sample.
Several chemicals were added in the process. At the end, starch
is dropped one drop at a time into the sample until the liquid
becomes clear. The remaining amount of starch tells you the DO
value. In the last few months of our study we used a DO probe
which measured the DO level using a computer. In addition to the
DO testing we measured pH and temperature. To do this, we placed
probes that were connected to a yard stick into the water. Then
we waited for the values to stabilize on an attached calculator
and recorded the data
