SCCF Marine Lab conducting tests for treating algae
The Sanibel-Captiva Conservation Foundation reported that many lakes on Sanibel are at the point where they have continuous blooms of harmful algae. Its Marine Laboratory is conducting jar tests on water samples from several lakes experiencing the blooms. The tests involve taking small samples and adding different treatment chemicals to multiple samples to determine if nutrients are reduced and the harmful algae blooms dissipate, without adding additional harmful residuals to the water.
The SCCF continued that this is not unique to Sanibel. As South Florida’s lakes become more enriched with nutrients, such as nitrogen and phosphorus, people are becoming concerned about the blooms happening in their backyard lakes. Many of Florida’s urban waterbodies have become polluted with nutrients due to the consequences of development. Septic systems, fertilized turf, decreased tree canopy and more impervious surfaces are characteristics of conversion of natural landscapes, which increase the amount of nutrients in waterbodies and result in algae blooms.
Best management practices are encouraged by local governments and, in many cases, communities do implement the practices and have been reducing nutrient inputs through their efforts. However, the waterbodies are often so high in nutrients that reductions in nutrients will not have a significant effect without some type of in-lake intervention, according to the SCCF.
Chemical treatment of hypereutrophic — very badly polluted — lakes is becoming more common. Chemicals such as alum or aluminum sulfate, ferric sulfate or iron, bentonite clay, hydrogen peroxide and calcium carbonate can be used to kill algae, tie up nutrients and settle out solids to clarify lake water. Some of these chemicals can have adverse effects to lake ecology if applied in large amounts.
The Marine Lab is conducting the jar tests to determine if nutrient levels can be reduced significantly without adding additional harmful residuals to the water. Different chemicals at different doses are applied to each sample. The samples are then tested to see if the nitrogen and phosphorus are reduced and if any residual aluminum or iron are left in solution. If the levels can be reduced significantly, the treatments may be attempted on a larger scale to treat algae.
To reach SANIBEL-CAPTIVA CONSERVATION FOUNDATION, please email