Big Trouble on the Big O

Recent aerial detail of Lake Okeechobee, near Clewisston, is nearly unrecognizabnle to locals. High water has snuffed out aquatic grasses that once thrived among these islands. From far left is sugar country, U.S. Highway 27, the levee and the Rim Canal.

Each January, state biologists run a trawl sampling on Lake Okeechobee to assess the black crappie population. They pull the trawl net six or seven times, a cycle lasting about 15 minutes. The average total catch is around 500 crappie, with the norm being 50 to 75 percent juvenile fish and the rest harvestable adults. That indicates the population is healthy and in balance.

That didn't happen in 2005.

“We pulled eight times,” says biologist Steven Gornak of the Florida Freshwater Commission, who has been working on the Big O since 1992, “and found a fraction of the crappie we normally get. We pulled eight more times and the final tally was only 146 crappie. We pulled twice as long and found less than one-third the crappie than we historically do. The most disturbing part was that only four of them were juvenile fish. It would appear that we have lost a year class.”

That's not good news for crappie fishermen, because while a speck can live six or seven years, there is a noticeable decline in the numbers of any year class after three or four years. The continued health of a crappie fishery depends upon the annual spawn and recruitment of those fry into the adult population.

Crappie aren't the only Big O fishery that appears to be in trouble.

Electro-sampling in 2003/04 showed respectable numbers of adult and juvenile largemouth bass. In 2004/05 studies there were still decent numbers of mature bass. But, young of the year (YOY) bass numbers were down to alarming levels.

“We did not see nearly the numbers of YOY and juvenile bass that we would expect,” Gornak noted, “and given the numbers of mature bass in our sampling we feel that unless conditions change, we are looking at only another two years, three years max, for that fishery.”

Okeechobee problems can be summed up in two words: high water.

In order for the lake to reach its maximum wildlife potential, water levels need to fluctuate between 13 and 15.5 feet. The lower figure should ideally be achieved by early June, and the 15.5-foot level by early December, following the rainy season and entering the “dry” season. This, according to FWC biologists, is where the lake is at its historical best.

Lower than normal water levels are not at all bad. They produce a natural drawdown that has the same effect on the rejuvenation of the littoral zones as do the manmade drawdowns conducted on Rodman, the Kissimmee Chain and other lakes. They may impede navigation while low-water conditions exist, but are ultimately beneficial.

High water is the killer. And, unfortunately, that's exactly where the Big O has been kept, especially since the hurricanes of 2004. As this is being written, lake levels are at 16.6 feet, with more water on the way. According to Gornak, that has a devastating effect on the lake.

Politics stand in the way of proper lake management.

“Okeechobee is a big lake,” he explains, “with a significant wind and wave action that moves a lot of bottom sediment. Under normal water levels the wave energy dissipates at the vegetated littoral zone and the sediment is deposited there. The littoral zone remains clean and clear, fish can live there, plants can grow, and the lake remains healthy.”

Raise the water level too high, and waves blow right past the outer vegetation edge; pound the littoral zone; uproot vegetation; and muddy the water so that sunlight cannot penetrate, which prevents plant seeds from germinating. In effect, it destroys both the sanctuary the fry need, and the filtering system that keeps the lake healthy. The more plants lost, the more turbid the water gets, so the problem perpetuates itself.

When vegetation dies off, any lake could turn into a phosphorous-rich “soup” incapable of supporting even a marginal fishery—much like the once-famous Lake Apopka.

“High water has caused significant vegetation loss in the past,” says Gornak, “but we have never experienced the vegetation loss that we are seeing now. Virtually all the bulrush is gone. You can forget peppergrass, and there is very little eelgrass left. Some hydrilla is trying to hang in there, and there are some lotus pads remaining in the boat trails. The only plants actually surviving in numbers are cattails, and they are shrinking with the continued high water.”

The solution is to lower the water, and the South Florida Water Management District and U.S. Army Corps of Engineers are aware of it. This fall they were releasing water in an attempt to get the lake down. That won't solve the problem, though. Gornak feels that in order to restore the critical vegetation and maintain the fishery, the lake level would have to be pulled down to 13 feet and left there for six or seven months.

Mother Nature has not been helpful in that respect. Hurricane Wilma, which raced across South Florida in October, added to what was already a summer of unusually heavy rains. The storm also churned up vegetation, in the same way the storms of 2004 did.

Politics also stand in the way of proper lake management. Influential sugar farmers in the Everglades Agricultural Area, south of the lake, insist the water managers maintain high lake levels for possible irrigation needs in drought times. It's a double-whammy, because historically, floodwaters dissipated into Everglades marshlands now occupied by sugarcane. Big Sugar fights to keep the lake high in the dry season, and then, by virtue of artificial geography, stands in the way when drainage becomes critical for the health of the lake. A “drawdown” of Lake O means discharging the nutrient-rich fresh water through manmade canals to the Caloosahatchee and St. Lucie estuaries.

The discharges east and west amount to some 500 billion gallons a year, sent from the lake to sea in order to keep sugar farms dry. Residents of coastal areas, especially in Stuart and Fort Myers, are understandably upset by the gushes of water, which muddy the estuaries and threaten human health as well as wildlife and plants.

Activists on both coasts say that much more of the water must be drained to the south and that existing Everglades restoration plans are too little and too late.

“As far as the lake itself is concerned, it looks like we have lost the 2005 year class of bass and crappie,” says Gornak. ”If the water clarity and vegetation situation remains the way it is, we will probably lose 2006.”

See www.floridasportsman.com/confron and riverscoalition.org for more on Lake Okeechobee, the estuaries and the Florida Everglades.

FS