Boy Scouts Camp on Doctors Lake


July 21, 2017

Contact: Lisa Rinaman, St. Johns Riverkeeper

Jacksonville, FL — On July 12, 2017, St. Johns RIVERKEEPER took a sample of a blue-green algae or cyanobacteria bloom from Doctors Lake in Clay County. Test results from GreenWater Laboratories detected total microcystin toxin levels of 14.1 micrograms per liter, or more than 3 times higher than the Environmental Protection Agency’s draft criteria for recreational exposure of 4 micrograms per liter. 

Microcystins are toxins produced by cyanobacteria, or blue-green algae. Exposure to algal toxins can cause adverse health effects in humans and animals, including skin irritation, flu-like stomach ailments, hay fever-like symptoms, itchy eyes, asthma, and even liver damage.

On July 12, the St. Johns River Water Management District (SJRWMD) also took four samples from Doctors Lake, all with microcystin toxin concentrations higher than the EPA safe exposure threshold.

SJRWMD sample location and toxicity results include:
Doctors Lake Boat Ramp – 10.4 micrograms/liter of microsystin
East shore of Doctors Lake – 9.20 micrograms/liter of microcystin
Swimming Pen – 9.05 micrograms/liter of microcystin
Southwest shore of Doctors Lake – 4.75 micrograms/liter of microcystin

Note: The SJRWMD takes samples at .3 meters below the surface. It is likely the toxin concentrations were actually higher at the surface where the public and pets are more likely to come into contact with the cyanobacteria.

Since it is not possible to visually tell if a bloom is toxic, it is recommended to avoid all algal blooms. Do not come in contact with the algae, and do not allow pets or livestock to swim in or drink water where blooms are present. If you, your children or your animals accidently come in contact with an algal bloom, wash with fresh water and soap after skin contact and avoid swallowing or inhaling water. Wash your animals thoroughly before they start to groom themselves. People with liver problems (such as cirrhosis or hepatitis) may be at increased risk of harm from these toxins.

To report algal blooms, call 855-305-3903 or go to

You can also track recently reported algal blooms and sampling results at this Florida Department of Environmental Protection website:

Algal blooms often occur as a result of excessive concentration of nutrients, in our river and waterways. Too much nitrogen and phosphorous can feed uncontrolled algal blooms that deplete oxygen in the water needed by fish, reduce light that is essential to submerged vegetation, and threaten the health of both humans and aquatic life.

The St. Johns River, including Doctors Lake, suffers from an excess of nutrients from failing septic tanks, manure, commercial and municipal wastewater discharges, stormwater runoff, and fertilizers that regularly wash into the river.

We all can make a difference by reducing our use of fertilizers, preventing runoff, maintaining septic tanks, and adopting other River Friendly practices. Learn more at

"Unfortunately, most of these algae blooms that are occurring in Doctors Lake and the St. Johns River have the potential to produce dangerous toxins,” states Lisa Rinaman, the St. Johns Riverkeeper. "However, our river will continue to be sick and the health of our families will continue to be at risk from exposure to toxic algae, until we reduce the amount of nutrient pollution going into our waterways."