Highly toxic blue-green algae bloom reported in C-44 Canal 10 days ago now gone, DEP says

A highly toxic blue-green algae bloom reported April 21 in the C-44 Canal linking Lake Okeechobee and the St. Lucie River has vanished, the Florida Department of Environmental Protection reported Friday.

The small bloom just east of the Port Mayaca Lock and Dam near the Florida East Coast Railroad bridge contained the toxin microcystin at a level of 120 parts per billion, the DEP reported last week. A level of 8 parts per billion or higher is hazardous in recreational contact, according to the Environmental Protection Agency.

A South Florida Water Management District team visiting the site Tuesday couldn't find the bloom, the DEP reported In its weekly algae report issued Friday.

The team took a sample anyway, and results showed no toxins and a mixture of algae species. 

More:Algae bloom in canal leading to St. Lucie River 15 times too toxic to touch

Gates at the Port Mayaca Dam have been open for several weeks, and water has mostly been flowing from the canal into the lake.

The St. Lucie Lock and Dam gates are closed, meaning water from the C-44 Canal is not being released into the St. Lucie River. Lake discharges to the river are unlikely in the near future as the lake elevation is slightly below 11 feet 6 inches, about 2 feet lower than normal for this time of year.

More: Lake Okeechobee dropping during dry season; how low will it go?

The probability of toxic blooms in Lake O and surrounding waters increases this time of year as temperatures rise and days get longer

"I expect more blooms to develop as time goes on," Malcolm McFarland, a research professor at Florida Atlantic University's Harbor Branch Oceanographic Institute at Fort Pierce, told TCPalm when the bloom was reported. "How bad it gets is really hard to predict; but with lots of rain and warmer weather to come, it's likely to get worse."

Tyler Treadway is an environment reporter who specializes in issues facing the Indian River Lagoon. Support his work on TCPalm.com.  Contact him at 772-221-4219 and tyler.treadway@tcpalm.com.