Live video coverage underway now for 2:45 p.m. launch of Delta IV Heavy on its historic final flight from Cape Canaveral.
HEALTH

Blue-Green Algae Task Force questions Army Corps plan for predicting harmful blooms

Tyler Treadway
Treasure Coast Newspapers

The Army Corps of Engineers asked the Florida Blue-Green Algae Task Force on Thursday for a "thumbs up" on a plan to operate Lake Okeechobee in a way to reduce the threat of harmful blue-green algae blooms.

They didn't get it.

The Corps is developing a new set of guidelines known as the Lake Okeechobee System Operating Manual, or LOSOM, to determine, among other things, if, when and how much lake water will be discharged east to the St. Lucie River and west to the Caloosahatchee River.

The third meeting of Florida's Blue-Green Algae Task Force included (from left) Valerie Paul, Michael Parsons and Wendy Graham and included presentations from the Florida Department of Health, Florida Department of Environmental protection, public commenters and more, Thursday, Aug. 1, 2019, at Florida Atlantic University’s Harbor Branch Oceanographic Institute in Fort Pierce.

The Corps plans to have a recommendation for new guidelines in July and, after further review, have them become effective in 2022, replacing the Lake Okeechobee Regulation Schedule, aka LORS.

More: Treasure Coast residents voice concerns about Lake O

The No. 1 objective of LOSOM is to "manage the risk to public health and safety," Col. Andrew Kelly, Corps commander for Florida, told the task force Thursday in a Zoom meeting.

But another objective is to "enhance the ecology of Lake Okeechobee" and the St. Lucie and Caloosahatchee rivers, which receive lake discharges that can cause massive toxic algae blooms.

Corps officials outlined how they've developed what they call an "algal bloom risk metric," a way of predicting when algae blooms could develop in the lake and be discharged to the estuaries.

The metric is based on chlorophyll levels, and Corps scientists have compiled data showing that over the years, higher levels of chlorophyll in the water have led to higher risks of algae blooms.

Blue-green algae is actually cyanobacteria, naturally occurring microscopic bacteria that, like plants, uses chlorophyll to produce food from nutrients and sunlight.

More: Here's what you need to know about blue-green algae

'Is it good enough?'

"What we're looking for is a thumbs up," Kelly told the task force. "Is this a good enough method?"

Not really, the task force replied.

Task force members, while they thanked the Corps for taking algae blooms into the consideration in the lake's operation, seemed to think the plan was too simplistic.

"This is a very simple model with one driver," said task force member Wendy Graham, head of the Water Institute at the University of Florida. "There are lots of other things that are driving those algae blooms."

A combination of factors can cause normal levels of blue-green algae in water to explode into a full-tilt bloom: high levels of nitrogen and phosphorus from fertilizer runoff and septic tank leakage; long, hot days; and low salinity.

Task force member James Sullivan, executive director of Florida Atlantic University's Harbor Branch Oceanographic Institute at Fort Pierce, said he understood the Corps "is in a serious time crunch, but there may be more elegant ways to do this risk assessment."

When task force members noted data provided by the Corps didn't show increases in chlorophyll during years with massive blooms in the St. Lucie River estuary, 2018 in particular, 

Florida Chief Science Officer Tom Frazer, who leads the panel, said questions about the Corps' proposal "limit its utility. There may be ways in the near future to improve on it. And with much more effort and technological advances, there likely will be a more comprehensive forecasting tool."

Tom Frazer, Florida's chief science officer and leader of the newly formed Florida Blue-Green Algae Task Force, seen Thursday, Aug. 1, 2019, during the third meeting of the task force at Florida Atlantic University’s Harbor Branch Oceanographic Institute in Fort Pierce.

Frazer said the task force would offer the Corps advice on their proposed bloom forecasting method, "but I don't see us as signing off on it as being 'the tool.' That's their job, not our job."

Lower lake?

LOSOM will take into account the effects of projects scheduled to be completed by the time new guidelines are approved, including:

  • The strengthening of the Herbert Hoover Dike around the lake.
  • The C-44 Reservoir and Stormwater Treatment Area to store and clean water heading east to the St. Lucie River,
  • The C-43 Reservoir to store water heading west to the Caloosahatchee River
  • The Kissimmee River Restoration Project north of Lake O

Many environmentalists, particularly those along the St. Lucie and Caloosahatchee rivers, are hoping LOSOM will call for keeping Lake O at lower levels, reducing both the risk to the dike and the need for discharging lake water to the estuaries.

Task force member Michael Parsons, a marine science professor at Florida Gulf Coast University and director of the Coastal Watershed Institute in Fort Myers, told the Corps keeping the lake level "lower in the dry season cuts down on both blooms and discharges."

More: 'Crystal clear' water shows lowering Lake O worked, Mast says

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.