Lake Ivanhoe is one of 10 lakes in the Orlando area that is under a "lake alert" for algae toxins, according to the City of Orlando.
Lakes Ivanhoe, Copeland, and Sue were all placed under alert in the last few days because of algae bloom toxins found in the water; several others were closed back in December and early January for the same reason.
City staff advises park-goers to refrain from "swimming, recreating and irrigating in/from" the lakes under alert until they are retested and cleared.
The lakes currently closed due to algae toxin levels are: Copeland, Highland, Ivanhoe, Formosa, Rowena and Estelle for microcystins; and Lake Sue
Lisa Lotti, the city's Stormwater Compliance Program Manager, told Orlando Weekly
that Central Florida's lakes often see algae blooms like this when cold weather snaps cause the water in lakes to "flip" — the cold water on top sinks to the bottom, pushing the warmer, nutrient-rich water up to the top. Sunlight exposure on that nutrient-rich water then causes algae to bloom.
"This isn't uncommon for this time of year," said Lotti, during a phone interview Tuesday.
Lotti said the algae toxins found in the lakes can cause varying reactions in people and pets, depending on their sensitivity, hence the closures.
Skin irritations and respiratory issues are some of the signs of exposure to the algae bloom toxins, she said, but the real concern would be gastrointestinal issues if the water was swallowed.
"We think about our dogs playing in the water, maybe licking it off themselves," explained Lotti. "This decision [to close] is out of a preponderance of caution."
Another Orlando lake — Lake C, located east of Lake Underhill — closed Monday for elevated E. coli levels
"The city experienced a minor sewer overflow, which overflowed into the lake," said Lotti.
Lake C is now the third lake in Orlando closed for elevated E. coli levels, alongside lakes Davis and Fairhope, both closed in early December. Barker Park Canal, next to Clear Lake in West Orlando, has been closed since August last year for fecal coliform.
City officials are still looking into the sources of E. coli and fecal coliform in Davis, Fairhope and the canal. Lotti said their next step is to perform DNA testing on the E. coli in the lakes to see if it is an animal or human source. The city will also start source-tracking the canal's contamination in the coming weeks.
Lotti said that the city works with with the Florida Department Environmental Protection to test all the lakes on a routine basis, as well as when citizens report concerns to either the city or FDEP.
The local DEP covers multiple counties, so it can take some time for researchers to retest sites with abnormal levels, and more time passes before the lakes are allowed to reopen.
"That could be two weeks, three weeks, even four," she said.
For updates on these closures, visit the City of Orlando's Parks and the Environment website.
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