Dead fish in lakes Sampson and Rowell

A recent reported fish kill brought me out to explore Lake Sampson, a tributary of the Santa Fe River. Lake Sampson is joined by canals from Lakes Rowell and Crosby. The fish kill was observed in the canal connecting Lakes Sampson and Rowell.

The dead fish appeared to be coming from Lake Rowell. Lake Rowell is a shallow, stagnant lake fed by Alligator Creek. Alligator Creek acts as a drainage ditch that appears to flow from mining wastewater retention ponds, through a golf course and the City of Starke. Lake Rowell takes in all this runoff and eventually flows into Lake Sampson which empties into the Santa Fe River.

Lake Rowell also provides the perfect conditions for invasive hydrilla. The lake is currently covered in dense mats, blocking the flow of water, further exacerbating conditions for fish.

Fish die-offs are not unusual after heavy rains which occurred three weeks prior.   Run-off from heavy rains washes sediments and fertilizers into creeks and lakes increasing algae blooms, reducing dissolved oxygen. Herbicides used to control weeds can also make matters worst when the weeds that are killed decompose.

Residents lamented the changes in the lake over the last two decades. Once clear and teaming with otters, turtles, and fish, it has lost much of its clarity and wildlife. One year, hundreds of turtles died. Samples of these turtles were taken and analyzed but were unable to determine the cause. Freshwater clams and  thousands of apple snails have also diminished in numbers. Once a prized destination for sports fishing, Lake Sampson has lost its appeal.

Some residents of Lake Sampson suspect the untreated wastewater from Chemours has been killing their lake. After Irma, Chemours released millions of gallons of wastewater leading to one of the biggest floods affecting the Santa Fe River basin. Chemours has been operating in the area since the late 1940’s. This event generated a great deal of distrust of this mining industry. 

 Florida’s Lakewatch monitors nutrient levels over time showing increased nutrients and decreased clarity. The clarity is important  for healthy vegetation that feeds wildlife. The University of Florida’s LAKEWATCH program, and the Florida Lake Management Society are dedicated to protecting these critical resources through citizen education and support for citizen volunteer programs. Nitrogen and phosphorus have greatly increased since the early 2000’s , reducing clarity and negatively impacting this habitat.

These lakes are becoming less hospitable for wildlife. Bradford County Soil and Water, is exploring solutions and striving to make a positive impact by addressing the need for debris removal within Alligator Creek to improve drainage and reduce flooding. They are also exploring a mechanical means of weed control within Lake Rowell. The nutrient loading however remains an untouchable topic. High nitrates and phosphates continues to be the problem that nobody can resolve.

OSFR President Joanne Tremblay
joanne.tremblay@oursantaferiver.org
“Giving Our River A Voice”