Low levels of the toxin microcystin were detected in water collected in Lake Okeechobee where a large algal bloom has been reported, according to the Florida Department of Environmental Regulation. Higher levels of microcystin were detected on the Caloosahatchee River in Glades County and in Lee County. The highest level of toxins detected this week was in a sample collected on the Caloosahatchee River at the Alva bridge on June 25, with microcystin levels of 308.07 micrograms per liter.

To date, most of the samples from Lake Okeechobee have had no toxins detected or tested below 1 microgram per liter.

The World Health Organization (WHO) considers microcystin levels below 10 micrograms per liter to be safe for recreational contact.

• On June 21, a sample from the St. Lucie Lock in Martin County had Microcystis aeruginosa (a cyanobacterium) as the dominant taxon. No microcystin was detected.

• A sample taken June 25 on Lake Okeechobee at Moore Haven found Microcystis aeruginosa was dominant. Microcystin levels were 3.3 micrograms per liter. No other toxins were detected.

• On June 25, dense mats of algae were observed on the surface of the Caloosahatchee River at Ortona; Microcystis aeruginosa was dominant in the sample. Microcystin levels were 26.3 micrograms per liter. No other toxins were detected.

• On June 25, a sample taken at the Port Mayaca lock in Martin County had Microcystis aeruginosa dominant. Total microcystin level was 2.2 micrograms per liter, No other toxins were detected.

• On June 25, FDEP sampled an algae bloom at Port Mayaca in Martin County. The dominant taxon was Microcystis aeruginosa (a cyanobacterium). Microcystin levels were measured at 2.2 micrograms per liter. No other toxins were detected.

• On June 25, an algal bloom on the Caloosahatchee near S. Olga Road in Lee County had Microcystis aeruginosa dominant. Microcystin level was 25.41 micrograms per liter. No other toxins were detected.

• On June 25, microcystin levels of 308.07 micrograms per liter were detected in an algal bloom on the Caloosahatchee River at the Alva bridge. Microcystis aeruginosa was the dominant taxon. No other toxins were detected.

• On June 26, microcystin levels of 463.34 micrograms per liter were detected in an extensive algal bloom on the Caloosahatchee River in Lee County. Microcystis aeurginosa was dominant. Anatoxin level was 0.34 micrograms per liter.

• On June 26, a sample collected at the Swim Beach downstream of the S-79 water control structure on the Caloosahatchee River had microcystin levels of 6.5 micrograms per liter; Microcystis aeruginoa was the dominant taxon.

• On June 26, microcystin levels of 4 micrograms per liter were detected in an algal sample at the Tiki Hut at State Road 31 in Lee County.

• On June 26, microcystin levels of 6.06 micrograms per liter were detected in a sample taken near the Orange River Tree Farm on the Caloosahatchee River in Lee County. Dominant taxon was Microcystis aeruginosa.

• On June 26, an algal bloom on the C-44 Canal in Martin County below the S-80 water control structure had mixed algae with no dominant species. Microcystin levels were 0.59 micrograms per liter. No other toxins were detected.

• FDEP also found visible algae on the surface of the water and in the water column in the C-44 Canal below the S-80 water control structure on June 26. Test results are not yet available.

Algae blooms are also reported in other waterways in Florida in the past two weeks.

• On June 18, an algae bloom in Doctors Lake in Clay County was found to be mixed algae with no dominant species. Total microcystin level was 0.73 micrograms per liter. No other toxins were detected.

• On June 18, an algae bloom was sampled at Buffalo Bluff on the St. Johns River in Putnam County. Planktolynbya limnetica and Aphanocapsa sp. were co-dominant. Microcystin levels were 0.20 micrograms per liter. Saxitoxin/paralytic shellfish toxin level was 0.33 micrograms per liter.

• On June 18, an algae bloom on the St. Johns River at Palatka City dock was dominant for Microcystis aeruginosa. Total microcystin levels were 0.27 micrograms per liter, Saxitoxin/paralytic shellfish toxin level was 0.24 micrograms per liter.

• On June 18, an alage bloom was reported at the mouth of Swimming Pen Creek in Clay County. The dominant species was Dolichospermum circinale, Microcystin levles were 1.69 micrograms per liter. Saxitoxin/paralytic shellfish toxin level was 0.07 micrograms per liter.

• On June 19, an algae sample from St. Johns River at Babbits Landing had Microcystis aeurginosa as dominant. Toxin testing levels are not yet available.