The Re-Birth of Lake Apopka — EATING FLORIDA

The focus of our next central Florida topic is about 15 miles northwest of downtown Orlando. With an areal extent of slightly less than 50 square miles, Lake Apopka is the third largest lake in Florida. It’s also the principal source of the beautiful Ocklawaha River. The events that transpired at the Lake offer those who are willing to learn a hard lesson in how thoughtless human use nearly destroyed a nationally renowned resource and how a combination of citizen effort, science, political pressure, and fierce determination may result in successful restoration. Please note that the key word is may.

Most of Lake Apopka’s serious problems are of fairly recent origin. However, its trail of tears started in 1895 with construction of the Apopka-Beauclair Canal that linked Lake Apopka to a chain of lakes downstream. That was the first step in the downward spiral into eventual environmental degradation. But it wasn’t until the 1920s that land use changes in adjacent areas spelled the beginning of the end of the Lake as a natural system.

In the early 1920s Lake Apopka was hit by a series of staggering blows in the form of external nutrient loads. First, sewage from the lakeside city of Winter Garden was pumped into the Lake. Second, organic wastewater from nearby citrus processing plants was piped in. And third, agricultural run-off laced with fertilizers and pesticides came as unsolicited and unwanted non-point source pollution from bordering farms. All without thought of inevitable consequences. The last straw arrived in 1947 in the guise of a hurricane that swept through central Florida and destroyed much of the shallow Lake’s rich aquatic vegetation. One month later, Lake Apopka publicly announced that it was dying with the first of many algal blooms (rapid increase in the population of algae in freshwater or marine aquatic systems).

Until its precipitous decline in 1947, the clear waters of the densely vegetated Lake were nationally known for extraordinary sports fishing. For decades bass fishermen from all over the country regularly rated it the best freshwater fishing in the United States. That came to an abrupt end. The Lake’s nutrient overloads and resulting algal blooms since the late 1940s created a pea-green open sewer and caused frequent fish kills. The Lake’s environmental quality, recreational opportunities, and economic value went into a disastrous and precipitous decline. Sad to say, it’s beyond any doubt that Lake Apopka contributed heavily to the subsequent decline of water quality in lakes downstream and in the Ocklawaha River. Lake Apopka had suddenly morphed from a thing of natural beauty into an environmental disaster of the first rank.

But nutrient loaded sewage and agricultural run-off were not the end of Lake Apopka’s travails. In 1980, a waste pond at the nearby Tower Chemical Company overflowed, dumping large quantities of powerful chemicals into the Lake. And not just any chemicals. We’re talking about really nasty pesticides, especially DDT and dicofol. Soon afterward, 90 percent of Lake Apopka’s alligator population died or simply disappeared. So, what was the reaction of the people responsible for all that damage: it was ho-hum and yawns all around. They went about their business as if nothing out of the ordinary had happened and bristled angrily at suggestion that they were to blame for any of the Lake’s environmental problems.

However, help was on the way from people who lived around the Lake and were determined to see it restored. Environmental assistance also came from a totally unexpected source: the State of Florida. Now there’s a genuine shocker. It’s no secret that the driving force responsible for pushing the State to actually do something about the horrible mess at Lake Apopka was a grassroots organization of fiercely determined local citizens who were fed up with the destruction of their lake. But the real surprise was that the State actually got off its dead ass and did something environmentally constructive.

After years of unsuccessful and uncoordinated individual efforts a number of people got together and formed a group that became known as the Friends of Lake Apopka (FOLA). The members of FOLA recognized that none of them had unlimited financial resources or unlimited time to devote to a cause they knew was just. So they devised a strategy of intense collective effort that focused on lobbying elected officials and agency staff. Their message was simple and consistent. They wanted their lake back as a natural resource. And they weren’t going to go away unless something was done about it. Period. They then applied constant and unrelenting pressure that, according to the complaints leveled by their moneyed opponents, bordered on the harassment of their political representatives at all levels. Ordinary people petitioning their elected representatives to address legitimate grievances. And that supposedly constituted harassment. Welcome to the real world of American politics.

To every one’s astonishment the tactics of intense and unrelenting political pressure worked. The Lake Apopka Restoration Act was passed by the Florida Legislature in 1985. It required the St. Johns River Water Management District (SJRWMD) to develop and implement plans to restore Lake Apopka to a water quality condition that made it suitable for recreation. Meaning fishing and swimming. And the Surface Water Improvement and Management (SWIM) Act of 1987 included the Lake on a list of waterways of highest priority for restoration, making pollution reduction a primary goal. Planning and feasibility studies for lake improvements began shortly thereafter. To its lasting credit, SJRWMD committed itself to working with all affected parties and stakeholders to re-create a clean Lake Apopka that would be a recreational and economic engine to benefit central Florida and the State as a whole. People at FOLA thought it was time to get down and celebrate. The primary goals for the restoration of the Lake’s ecosystem were to:

• Reduce the amount of phosphorus entering Lake Apopka from farms on the lake’s north shore by purchasing those lands and restoring the area to a more natural condition.
• Remove phosphorus and other suspended sediments from the lake by filtration through the Marsh Flow-Way (a constructed wetland covering approximately 760 acres) and by mass removal of gizzard shad.
• Improve the food-web structure by removing gizzard shad.
• Restore habitat through restoration of the shoreline (known as the littoral zone), increased fluctuation in lake levels and restoration of the north shore farmlands to wetlands.

After the studies were complete the District began negotiations with the local farmers who had been responsible for discharging nutrient-laden runoff to the Lake for decades. As if it had been their own no-cost, personal sewage disposal system.

After only a few years, the resulting agreements brought about a 60 percent reduction of phosphorus discharges from the farms. Real progress was being made. Then in 1996 the State’s Lake Apopka Restoration Act authorized the District to set a new phosphorus water quality standard and provided funding to initiate a mandated buyout of all the “muck” farms — with organic soils that are relatively decomposed, black in color, and very fertile — on the north shore of the Lake. The District completed its buyout of the farms in 1999 at a cost of quite a few million dollars.

The District’s Governing Board approved a rule in 2002 limiting the amount of phosphorus that can be discharged into Lake Apopka or its tributaries as a result of new construction in the Lake’s watershed. SJRWMD has also partnered with local, State, and federal agencies to:

• Purchase more than 19,000 acres of agricultural land along the lake’s north shore, reducing the discharge of phosphorus from the farms and providing an opportunity to restore the former marshes to wetlands. About 5,000 acres have been restored to wetlands, with a goal to reflood a total of 13,000 acres.
• Operate the Marsh Flow-Way since November 2003 and, through 2009, filter 2.6 times the lake’s volume — resulting in the removal of 62 million pounds of suspended solids and 37,300 pounds of phosphorus.
• Harvest gizzard shad since 1993, and through December 2009, removing more than 125,700 pounds of phosphorus and 374,800 pounds of nitrogen in fish tissue and preventing them from recycling phosphorus by feeding in the lake sediments.
• Replant six native wetland species of vegetation in the water along the lake’s shoreline, which helps restore fish and wildlife habitat.
• Work with the Friends of Lake Apopka and the East Central Florida Regional Planning Council to develop a plan to ensure that future development does not negatively impact the lake

The positive consequences of nutrient reductions in the Lake first became apparent as early as 1995 when the total phosphorus count hit new, much lower levels. And since mid-1995 chlorophyll levels have also declined. All good news. Those significant increases in water quality and clarity resulted in a spontaneous return of native aquatic vegetation, especially the productive eelgrass. Such vegetation not only provided valuable fish habitat but had the additional benefit of aiding the Lake’s recovery. More good news.

To further cut the total phosphorous, the District embarked on a program to remove millions of pounds of gizzard shad, a trash fish that had greatly raised phosphorous levels. Since then, SJRWMD scientists monitoring the Lake have recorded remarkable improvements in the Lake’s water quality. So it should be no surprise that recreational fishermen soon were reporting increased catches. The turn-around was genuine but disaster loomed on the horizon.

In the decades before the large farmers on the north side of the Lake were bought out, they regularly back-pumped water into the Lake after summer rains flooded their low-lying fields. Naturally, those waters were in reality chemical cocktails laced with fertilizers and any number of lethal pesticides and herbicides.

In 1998, after SJRWMD spent millions to buy the farmland, the District’s project managers allowed the summer rain waters to collect on the former agricultural fields. Their idea was to recreate natural wetlands that had been integral components of the lake margins prior to agricultural operations. Shortly afterward, more than 150 species of birds were attracted to the newly formed wetlands. The project was beginning to look like an unqualified success. However, weeks later, in the fall of 1998 and winter of 1999, the birds began to die, first by the dozens and then by the hundreds. Until nearly 1,000 white pelicans and birds from 70 other species had croaked. It was a devastating blow to the restoration effort.

To no one’s surprise, restoration of the former fields to wetlands was immediately placed on hold. In 2001, after an exhaustive investigation that involved 200 necroscopies from a scientific sample of the dead birds, the U.S. Fish and Wildlife Service released detailed laboratory results. Their analyses found elevated levels of organochlorines (pesticides) in the birds’ tissues, including dieldrin, toxaphene, and DDT. In several birds the levels of dieldrin alone were sufficiently high to cause death. A field investigation conducted by SJRWMD scientists also identified soil in the flooded wetlands with toxaphene levels that were 500 times higher than was found in soils in adjacent non-agricultural areas. Suspicions confirmed.

As a side note, dieldrin had been removed from the market twenty-five years previously, in 1974. It’s a carcinogenic insecticide that permeates produce. The bad news is there’s no way to wash it off. It had been used for years at the Lake Apopka muck farms. DDT, which had a long and infamous record of bird kills in the 1950s and 1960s, had not been sold in the U.S. since 1972. And the manufacture of toxaphene, which began in 1948, was halted in the mid-1980s. But even after nearly twenty years in the environment, those poisons were sufficiently toxic to kill wildlife. After much tearful claims of innocence (or at least ignorance) by the former owners of the agricultural operations, the State forced the owners to remove the contaminated soils and replace them with clean fill having similar physical and organic characteristics.

Sad to say, that wasn’t the end of Lake Apopka’s travails. At the same time as all of the above activities were transpiring, a then little known biologist from the University of Florida began working with alligators. When Louis Guillette Jr. began studying alligators in 1985 his goal was straightforward and seemingly was guaranteed to keep him below everyone’s radar scope, except maybe that of his Department’s Tenure Committee.

Since a whole bunch of people, especially alligator farmers, wanted to use the reptile as a renewable resource (by harvesting its skin and meat), he simply wanted to determine the general state of alligator health in Florida to establish how many eggs could be harvested without adversely affecting the larger population. That was it in a nutshell. Well, he also was interested in alligators since they are what biologists regard as a sentinel species that indicates the overall health of the environment. In addition, he wanted to use the Florida alligator as a model for other crocodilians worldwide, the majority of which were endangered or threatened.

Guillette and his research team identified Lake Apopka as a potential source of gator eggs for their study. One of the reasons they picked Lake Apopka was that researchers with the U.S. Fish and Wildlife Service had studied it earlier and had found numerous problems with alligator eggs they had collected. After several field investigations Guillette’s team discovered that alligator eggs were in relatively short supply at sites around the Lake. They theorized that, owing to the previously mentioned chemical spill, the Lake’s general alligator population had been drastically reduced from what it had been a decade earlier. And worse, they determined that the gator eggs that they had collected were much more likely to die before hatching than eggs from other central Florida lakes.

Knowing something was definitely wrong with alligator reproduction at Lake Apopka, but not able to pinpoint a specific problem, Guillette decided to raise some of the gator eggs in his lab at the University. In 1992, he designed an experiment to help the research team identify and sort out the issues. His team of young biologists collected two sets of alligator eggs, one from Lake Apopka and the other from Lake Woodruff, which was just north of the central Florida city of De Land. From previous research, Guillette knew that Lake Woodruff’s alligator population was healthy and thriving. His research design was fairly simple: normal eggs from Lake Woodruff would serve as a control group to help the team determine exactly what was happening to the Lake Apopka gators.

Guillette’s initial results proved both informative and puzzling. When alligators from each lake hatched, there were obvious differences in their rates of survival. Many of the Lake Apopka hatchlings died within the first two weeks. Being a thoughtful professor type, Guillette wondered why the female alligators in Lake Apopka were having problems producing eggs that were viable. He had all kinds of information but they appeared to be disparate, almost unrelated. The puzzle pieces didn't fit together in a way that made sense.

His research team’s initial theories of what was causing the problems were not linked to chemicals. They thought it had something to do with extremes in temperature or the gas environment in the nest. They also tried to determine if the main cause was nutrition.

But even more significant differences emerged when Guillette began to measure hormone levels in male and female alligators from both lakes and quickly detected atypical results in Lake Apopka alligators. Males exhibited such severely depressed testosterone levels that they approached levels found in females. Levels that were over three times lower than those of the male part of the control group from Lake Woodruff. Moreover, Apopka’s female gators had twice the amount of estradiol (estrogen) that was characteristically found in normal females. 

The evidence seemed to show that feminization of both male and female embryos had occurred during development. That wasn’t all. The adult alligators’ testes and ovaries exhibited strange bio-structures that Guillette had never seen in a healthy population. Despite the males typically exhibiting poorly developed testes they also had advanced spermatogenic activity in which the testes of the newborn and six-month old animals had already begun producing sperm. Another anomaly that didn’t fit with the collected data.

Not to be left out of that puzzling picture, the research team found that the female gators were also characterized by unusual structures in their reproductive organs. Under normal conditions, alligator ovaries contain a number of bio-structures called follicles, with each individual follicle housing a single egg. However, the individual follicles of Lake Apopka females housed up to three or four eggs. And instead of just one nucleus those eggs contained many. When the Lake Woodruff alligators were tested, none of those abnormalities was detected.

A conscientious scientist, Guillette worried he must have done something wrong to get results that were so off the wall. So he and his team laboriously repeated the same experiment the next year. To his surprise, the results proved the same. Whoa, talk about a disturbing trend. It was time for Guillette to sit back and think about what the hell was going on in Lake Apopka. What had caused all those gender defects?

Guillette already knew about the ground-breaking research of John McLachlan of the National Institute of Environmental Health Sciences on compounds in the environment that were endocrine disruptors. He also was aware of Howard Burns’s work on diethylstilbestrol (DES), a synthetic estrogen, and the birth defects it caused in rodents and humans.  But most importantly he knew that Theodora Colborn, a Senior Scientist with the World Wildlife Fund, was doing research on the state of the environment in the Great Lakes. Colborn had painstakingly assembled a great deal of information on significant changes in animal populations, especially population declines, birth defects, behavioral problems, and population crashes. All of which fell under the purview of the endocrine system. She concluded that certain chemicals had disrupted embryonic growth in Great Lakes animal populations by mimicking or blocking the body’s own natural hormones. When Guillette put the research of Burns, McLachlan, and Colborn together in the context of what was happening with the alligators at Lake Apopka and with the effects of the earlier chemical spills, the light bulb went on in his head and all the seemingly separate threads started twirling together to form a coherent fabric.

Guillette’s research team took blood and tissue samples from the alligators they caught at Lake Apopka and also a variety of physical measurements, including phallus size. Another surprise they found was that the penises of the Apopka males were about 25 to 30 percent smaller than those of normal males. But perhaps their most significant finding was that alligator penises were the shortest in that part of Lake Apopka closest to the site of the former Tower Chemical Company. That wasn’t the end of the surprises. Back in the lab the tissue samples revealed high levels of a strange chemical known as p,p’-DDE, which is produced as DDT deteriorates in the environment. The DDT derivative wasn’t the only finding that was out of the ordinary. Lurking in the gator blood and tissue samples was a host of other nasty chemical contaminants.

Guillette suspected that chemicals in Lake might have blocked the male alligators’ internal response to their own hormones. He knew that penile growth, whether in alligators or humans, was dependent on two androgens (testosterone and dihydrotestosterone). In a population of normal alligators, higher androgen levels resulted in more growth. But if chemicals in the Lake had blocked the effects of testosterone in the males, Apopka’s male gators would have smaller penises. Plus, no direct relationship would be found between penis size and the amount of testosterone present in an alligator’s system since their puny peckers would not be caused by lowered androgen levels. He quickly began refining a hypothesis that multiple chemicals in the environment had tricked the developing embryo into thinking that it was getting a normal signal when in fact it was receiving an abnormal signal. Which resulted in an abnormal embryo that grew into an abnormal individual that may have looked normal externally but was unable to function or behave normally. Bingo. Suddenly the puzzle pieces looked considerably less confusing.

Guillette tested his theory in the lab and found that Lake Apopka alligators’ penis size did not directly correlate with the levels of testosterone in their blood. Which meant that something external, something in their environment, was preventing the hormone from having its genetically intended effect.

When the research team collected samples from the Lake they found that the water was relatively clean. So they reasoned that the gender-influencing chemicals from the 1980 spill might have migrated into the food system. Alligators are top predators, sitting at the apex of their food pyramid. By eating such typical prey species as fish, frogs, and snakes, the gators had inadvertently accumulated chemical contaminants like p,p’-DDE that moved from small prey to the larger predators, becoming more concentrated with each stage of the journey. The contaminants were then transferred through impregnated female gators to their eggs, where they could negatively affect embryo development.

Suddenly, everything made sense. The drastic population decline. The unusual bio-structures present in the male and female reproductive organs. The puny peckers and strange ovarian follicles. The abnormal testosterone and estrogen levels. All clear signs of jumbled hormone signaling that occurred during embryo development. And the guilty agents? Guillette thought they were the manmade chemicals spilled into the Lake in 1980. But he had to prove it scientifically.

Guillette decided to run a more sophisticated experiment and treat eggs in the laboratory with p,p’-DDE and other chemicals. If he could reproduce the same abnormalities in the lab as were found in the wild Lake Apopka gators, the experiment would demonstrate that the chemicals caused the defects. Guillette’s research team collected a clutch of normal eggs from Lake Woodruff and added a mixture of manmade chemicals, hoping to reproduce the effects recorded in the Lake Apopka gator population.

The results were highly significant. Application of a combination of the two most common contaminants in Lake Apopka, DDD and DDE, caused depressed testosterone, genital deformities, and other anatomical defects in the Lake Woodruff male alligators that would have otherwise been normal. The same chemicals also caused abnormally elevated estrogen levels in tested females.

Guillette’s premise was right on target. He had demonstrated that the presence of those toxins in the environment resulted in abnormal alligator populations that had grave reproductive defects. His research results were significant far beyond the borders of Lake Apopka.

Implications

More recently, Guillette’s research turned up gators with shorter penises and abnormal hormone levels in relatively clean Florida lakes, not ones adjacent to highly polluted sites like Lake Apopka. His findings suggest that background or just slightly higher levels of chemical contamination may cause permanent changes in embryo development. At least in alligators. But biologists’ biggest worry is that humans are exposed to those levels of dangerous chemical toxins every day and very few scientists have looked into their effects on our reproductive organs. And that’s a really scary scenario. After all, mammals use hormones that are very similar to those that reptiles use. In many cases, they use the very same hormones, for example, the same estrogens and androgens.

Guillette would like people to consider the hypothesis that human sperm count, at least in some populations, has declined by more than 50 percent compared to our grandfathers’ time. He also wants us to wonder if our grandsons will be half the men we are, at least in terms of sperm count. His major concern is that some human populations appear to have experienced dramatic changes in the rate of testicular cancer, increases in abnormal penis development, and increases in prostate disease.

At least some of those changes have been attributed to endocrine disruptors such as phthalates, which are a class of chemicals developed within the last century that are widely used as plasticizers and are proven to be testicular toxicants. Phthalates are used as industrial chemicals added to many consumer products such as margarine, snack chips, baby milk formula, cheese, garden hoses, inflatable toys, blood-storage containers, intravenous tubing, children’s toys, vinyl flooring and vinyl flooring adhesives, detergents, printing ink (used on plastic, board and foil-packed products), lubricating soils, automobiles, home furnishings, solvents, food packaging, plastic bags, automotive plastics, construction, plastic clothing, personal care products and some pesticide formulas.

I specifically mention phthalates because not only are they endocrine disruptors and are widely used but also because they are easily released into the environment because of the absence of covalent bonding between the phthalates and plastics in which they are key components. As the plastics break down, the release of phthalates is accelerated. People are commonly exposed to phthalates from a wide variety of sources, including food and drink containers, flooring, coatings of pharmaceutical pills, adhesives and glues, agricultural vaccines, building materials, personal-care products, medical devices, detergents and surfactants, packaging, children's toys, modeling clay, waxes, paints, and printing inks to name a few. Disturbing facts about the chemical include that most Americans tested by the Centers for Disease Control and Prevention have metabolites of multiple phthalates in their urine and children's exposure to phthalates is greater than that of adults.

The fundamental questions Guillette raises are simple but they may affect us in ways most have never considered.

• Do those human reproductive system abnormalities constitute signs of previously unconsidered but continuing public health hazards?
• Are low-level environmental contaminants responsible for disrupting the human endocrine system?

Very scary stuff, especially if Guillette is right.

Today, the good news from Lake Apopka far outweighs the bad. Happily, no more birds have died since 1999. And no one is running around trying to measure gator peckers either. Additional areas of eelgrass have re-appeared in the Lake as part of the natural process. Water quality and sport fishing continue to improve. The Lake has a long, long way to go but it had taken many decades of destructive and conscienceless agricultural practices to degrade a once pristine natural resource. It should be no surprise to learn that the restoration phase of Lake Apopka is expected to continue for between 25 to 50 years. And perhaps much longer. But if that isn’t a solid sign of hope I don’t know how else it could be interpreted.

The bad news is that despite the restoration project, pesticide levels in bird eggs have not decreased. Nor, however, have aberrant behavior or physiological abnormalities been observed. In truth, the jury is still out on how much success has been or can be achieved with restoration of the Lake.

The lesson we can learn from Lake Apopka is the same one we learned from the Cross-Florida Barge Canal. The specific situation was very different but most of the elements were the same. Here’s a brief summary. A fragile environment had been degraded. A determined grassroots organization sprang into action to save it. They used public outrage to support their struggle. Intense political pressure was applied. Scientific evidence was collected. The movement didn’t stop until political pressure forced the State to intercede and become part of the solution. The environment remains damaged but restoration approaching a natural state may be a possibility.

That formula worked for the opponents of the Cross-Florida Barge Canal and for the Friends of Lake Apopka. It can work to save other fragile environments. But only if outraged citizens make it happen. That’s the real lesson offered by Lake Apopka.