
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.