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Julie C.

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.

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 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.

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.

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 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 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