Two hours to 2:45 p.m. launch of Delta IV Heavy on its historic final flight. Weather remains main concern.
HEALTH

Algae bloom in Lake Okeechobee still covers 60 percent of open water; will cold kill it?

Tyler Treadway
Treasure Coast Newspapers
A satellite image taken Thursday, Oct. 25, 2018, shows a blue-green algae bloom covering about 63 percent of the open water in Lake Okeechobee, according to Sachi Mishra, a satellite oceanographer for the National Oceanic and Atmospheric Administration.

A blue-green algae bloom still covers more than half of Lake Okeechobee's open water, but cooler weather that started over the weekend could shrink or even kill it. 

The bloom was spread over 345 square miles, according to the last photos the National Oceanic and Atmospheric Administration took Oct. 25. The open water portion of the lake is about 550 square miles. The other 385 square miles of the lake is marsh.

The photo provides "a clear picture of the bloom condition" because it was taken during a time with little wind (1-2 mph), said NOAA satellite oceanographer Sachi Mishra.

"Some scum is visible along the southern shore," Mishra wrote in an email Monday. "Overall, the bloom has become milder."

Latest on red tide:Northern St. Lucie, Indian River County beaches still closed; cleanup underway

More:Red tide: Fate of Treasure Coast algae bloom is 'blowin' in the wind' | Map link

The "become milder" part made Paul Gray, Audubon Florida's Lake O expert, smile.

"That means the bloom already has started abating, that it's still a bloom but not as concentrated as before," Gray said Monday. "The cooler weather we're getting now will slow it down even more and, if we're lucky, end it once and for all."

Previously: 90 percent of Lake O smothered with algae bloom

The lake bloom has grown and shrunk and grown again over the summer and early fall. In early July, the algae bloom covered 90 percent of the lake's open water. 

Lake Okeechobee discharges

The Lake O discharges, which began June 1, were on a two-week hiatus at that time; but when they resumed July 13, the lake water brought lots of toxic algae with it.

More: Highly toxic algae at dam where Lake O water enters St. Lucie River

Algae blooms coming from the lake spread throughout many bays, canals and marinas along the St. Lucie River and remained until the discharges ended Oct. 5.

More: Lake Okeechobee discharges to stop

Algae blooms in Lake O aren't unusual, Gray said, but this year's has lasted longer than most because warm weather has lasted longer than usual and because of unusually high nutrient levels flowing into the lake.

More: Record phosphorus flow into Lake O casts doubt on pollution controls