The Indian River Lagoon鈥檚 algae bloom this year extended farther south into the lagoon than normal, coinciding with fairly extensive fish kills, according to the state鈥檚 Harmful Algal Blooms Task Force.
Harmful algal blooms, or HABs, form in waterways when large, highly-concentrated amounts of algae grow rapidly and release toxins, . An algae species called karenia brevis 鈥� also known as 鈥渞ed tide鈥� 鈥� is usually responsible for forming HABs in Florida鈥檚 saltwater habitats, .
FWC鈥檚 Fish and Wildlife Research Institute appoints members of the , which meets periodically throughout the year to determine strategies to research, monitor and mitigate HABs like red tide.
Director of FWC鈥檚 Center for Red Tide Research Kate Hubbard heads up the task force. At Tuesday鈥檚 meeting, she identified the Indian River Lagoon as one area of concern this year.
鈥淲e do have a bloom there [in the Indian River Lagoon] every year,鈥� Hubbard said. 鈥淏ut this year, the bloom extended further south, into the central lagoon, and it co-occurred with fish kills, fairly extensive fish kills.鈥�
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This year鈥檚 fish kills were linked to the lagoon鈥檚 low levels of dissolved oxygen, Hubbard said.
Dissolved oxygen in the water is what fish rely on to 鈥渂reathe,鈥� and without enough, they suffocate, .
Excess nutrients like nitrogen and phosphate can exacerbate the problem by spawning more algae to rapidly grow. As that algae decomposes, it can reduce the water鈥檚 oxygen levels enough to suffocate fish, .
The warmer water becomes, the less dissolved oxygen it鈥檚 able to hold, . This summer, high ocean temperatures created 鈥渦nprecedented heat stress conditions鈥� in the Caribbean Basin, including in the waters surrounding Florida.
For Brevard Indian River Lagoon Coalition chairman Craig Wallace, that tracks.
鈥淭his year? It was hotter than hell,鈥� Wallace said. 鈥淭he canal in my backyard is a major canal; it鈥檚 like, 12 feet deep. And I was getting readings of 90 degrees, in the water, for at least a month period of time this summer. I have not seen that before.鈥�
Wallace says his coalition formed in response to Brevard County鈥檚 massive fish kill in 2016, the same year county residents voted to pass a half-cent sales tax to fund water quality enhancement projects for the Indian River Lagoon.
Today, oversees those projects, sharing progress at monthly Citizen Oversight Committee meetings, which Wallace and other coalition members also participate in. The county's uses satellite imaging to track blooms in the Indian River Lagoon.
Wallace said he encourages Floridians and especially Florida newcomers to be conservative when using lawn fertilizer, because it often contains nitrogen and other nutrients that can reduce water quality.
鈥淭he amount of fertilizer that gets applied to lawns in Florida is just ridiculous,鈥� Wallace said. 鈥淭hat鈥檚 what kills. That鈥檚 the source of a lot of the algae.鈥�
provides some resources for state residents, including tips for how to fertilize responsibly, reduce stormwater runoff and select plants native to their area.
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