IF you have ever looked at a map of Florida, you would be hard pressed to miss the state’s big lake, sandwiched between the Atlantic and Gulf of Mexico. Named after the Seminole word for “big water,” Lake Okeechobee is a titanic body of water that was naturally formed six thousand years ago. Covering approximately 730 square miles, the lake is half the size of Rhode Island. That’s a lot of water.
After some devastating hurricanes in the 1920’s the US Army Corps of Engineers undertook efforts to prevent future flooding through a system of levees and canals. Today, almost all the discharges into and out of the lake are controlled by the Corps. As with so much of this country’s infrastructure, those levees and canals are in bad shape. The federal government ranks the flood control structures around the lake as some of the most at risk of failing in the country. With recent heavy rains in Florida, the fears of failure have resulted in catastrophic decisions, which will likely impact tarpon migrations and populations for years to come.
To understand the problem, we have to understand the dynamic. Usually, water is drawn from the lake to feed the water needs of the farm lands located south of the lake. This water is used for irrigating sugar cane, rice and many other crops. When the farmlands get too much rain, water is actually pumped back north and into the lake to protect the farms from flooding. Fertilizers, pesticides and a plethora of pollutants are pumped into the lake through this back-pumping process. This is usually only a localized problem within the lake. However, when there is too much water and the water in the lake rises more than about fourteen feet above sea level, the lake threatens to literally burst at the seams and the Corps steps in to “flush” the water from the lake. When this happens, the Corps does not send the water south, instead the pollution laden water is dumped to the east and west.
At its height this spring, Okeechobee was sending 2.6 billion gallons of polluted water a day into the Caloosahatchee River, aimed at Fort Myers and Pine Island Sound. To the east, 1.2 billion gallons per day was being dumped into the St. Lucie River heading for Stuart, Florida. The end result is tens of billions of gallons of coffee-colored, nutrient rich, pollution filled water being dumped onto reefs and marine environments raising bacteria levels and threatening the delicate balance for millions of aquatic species, including tarpon.
The mouth of the Caloosahatchee River is less than twenty miles from world famous Boca Grande Pass. Between the Pass and the river are some of the most heavily utilized marine environments for migrating tarpon in the Gulf of Mexico. Recent satellite tagging data has shown that large, spawning size female tarpon frequently travel miles up the rivers of southwest Florida during their spring migrations. Any disruption in these environments will disrupt their behavior and could alter their pre-spawn activities. Even more concerning, the lack of oxygen in these estuaries due to nutrient, algae rich lake water can cause a crash in the population of tarpon prey. Tarpon desperately need these food sources to provide nutrition and a caloric rich diet prior to swimming far offshore to spawn. A starving tarpon is not a healthy tarpon and certainly would not be in the best condition to spawn.
If anybody wants to know the adverse effects of changes in water quality on tarpon populations, they need not look any farther than Port Aransas, Texas. There is little doubt the changes in water management in Texas which followed World War II negatively impacted the tarpon populations and migrations of tarpon along the Texas coast. If a long term solution to Lake Okeechobee’s water woes is not fount quickly, the possibility of a significant crash in southwest Florida’s tarpon population is a real possibility.
Okeechobee's
Onslought
CONSERVATION CORNER
What does it mean
for Florida's Tarpon