Piney Z Lake

Marshall S.

Piney Z

Piney Z Overview
Piney Z lake of Tallahassee is one of the many Lafayette lakes under restoration. Beginning in 1995, the city purchased the 193-acre lake, along with 407 acres of land around it to rejuvenate the lake as a fishery. Few fish are currently present due to dense stands of aquatic plants, poor water quality including low dissolved oxygen, and a thick layer of muck coating the lakebed.

Piney Z got its name in the earlier part of the twentieth century when the area's pine trees resembled a "Z" configuration. Since then, the area was been somewhat deforested, and the trademark "Z" is no longer apparent. Just east of Tallahassee and off Apalachee Parkway, Piney Z will soon be open to the general public.

 

 

 

Piney Z Lake, Personal File, December 5, 2001.

Eutrophication
Eutrophication is the process by which lakes age and become more productive through plant growth. The process occurs naturally, but in many lakes, as in Piney Z, eutrophication has taken place unnaturally, by pollution and other various human activities. Often, this is called cultural or anthropogenic eutrophication, water pollution caused by excessive plant nutrients. In the case of Piney Z, these nutrients include fertilizers and other runoff that lands in Piney Z through storm water drains. Phosphates, commonly found in water softeners, also provide for powerful algal growth. As a result, this excessive plant growth rids the lake of much needed oxygen essential for fish development.

 

Eutrophicatio, National Teachers Assoc., 2001.


The Floridian Aquifer

The Floridian aquifer lies beneath all of Florida, southern Georgia, and parts of South Carolina and Alabama. At approximately 100,000 square miles, it is one of the most important water sources in the United States. At Piney Z, sinkholes lead to the Floridian Aquifer. Polluted, the water in theses sinkholes, suited for little more than catfish and alligators with its distinctive green algae tint, sinks into the aquifer. Sinkholes are closed depressions in the land surface caused by the absence of near-surface rocks or the collapse of underground caverns.

 

 

 

 

Jamal and Associates, Orlando.

Sinkholes are normal,however activities such as dredging and the pumping of well water can speed the process, creating the formation of collapse-type sinkholes (Above). In short, excessive loads on the Floridan aquifer promote the occurrence of sinkholes.

 

 

 

Floridan Aquifer, USGS, 2002.

Karst Topography
The term "karst" refers to limestone areas dependent upon underground solution and the diversion of surface waters to underground routes. It results in sinkholes, vertical shafts, disappearing streams, springs, and complex underground drainage systems and caves. Stalactites and stalagmites are formed by slowly dripping water involved in karst caves.

Water Quality
In order for Lake Piney Z to survive as an urban fishery, it is important to monitor the lake's water quality parameters. Temperature is important, as it must be ideal for the fish to live. Should it become too hot or too cold in the lake, the fish will not survive. Another important factor is dissolved oxygen. Oxygen is necessary for all forms of aquatic life, including fish. Dissolved oxygen is a measurement of the amount of gaseous oxygen dissolved in an aqueous solution. Piney Z has a dissolved oxygen deficiency, making fish growth difficult. Additionally, good pH levels are essential to a healthy fishery. pH is the measure of the acidic or basic nature of a solution. The concentration of the hydrogen ion activity in a solution determines the pH.

A student checks dissolved oxygen levels in Lake Piney Z.

Limiting pH Values
Minimum Maximum Effects
3.8 10.0 Fish eggs could be hatched, but deformed young are often produced
4.0 10.1 Limits for the most resistant fish species
4.1 9.5 Range tolerated by trout
--- 4.3 Carp die in five days
4.5 9.0 Trout eggs and larvae develop normally
4.6 9.5 Limits for perch
--- 5.0 Limits for stickleback fish
5.0 9.0 Tolerable range for most fish
--- 8.7 Upper limit for good fishing waters
5.4 11.4 Fish avoid waters beyond these limits
6.0 7.2 Optimum (best) range for fish eggs
--- 1.0 Mosquito larvae are destroyed at this pH value
3.3 4.7 Mosquito larvae live within this range
7.5 8.4 Best range for the growth of algae

It is important that the pH level be appropriate for the lake to work in healthy order. Turbidity is also an issue within Piney Z Lake. Put simply, turbidity is a measurement of the amount of light scattered by suspended organic (including algae) and inorganic particles within the water. With a greater suspended load, turbidity increases. Turbidity is most commonly measured in Nephelometric Turbidity Units (NTU), but may also be measured in Jackson Turbidity Units (JTU). Turbid conditions increase the possibility of water-born disease and change the composition of the lake's environment, in respect to fish, plants, and other organisms. Phospates and Nitrates also play an important role in aquatic life.

 

Two students record their observations at Piney Z Lake.

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