MELBOURNE, Fla. – Mark Maida cast his bait beyond pea-green streaks of slime near the banks of Lake Washington, where a potentially toxin-producing algae lingers in the main source of drinking water for more than 170,000 people.
The city hasn't found any algae toxins yet and assures the drinking water's safe. Any algae toxins from Lake Washington would be removed from the water before it reaches customers' taps, city officials say. But green wasn't a good look for the lake this week.
"It's nasty," Maida said Friday from Lake Washington's fishing pier. "Normally, you can see the bottom. The fish can't see the bait." Maida won't eat his catches. He tosses back what he hooks — mostly small gar.
Bright green algae blanketed waters near the lake's banks this week. The algae altered how the city disinfects its water, resulting in about 60 customer complaints of a strange odor to their drinking water. Excess algae has become an every-summer scourge for many Florida lakes, including Lake Washington. Rains bring remnants of fertilizers, leaky septic and sewer systems, and land-applied sewage sludge to fuel the algae explosions, sometimes toxic. Hot temperatures further fuel the algae growth.
"The algae is causing us to change our water production procedures," said Cheryl Mall, city spokeswoman. "Our water is being treated and it's safe."
Lake Washington provides two-thirds of the water supply for the city's 57,000 connections serving about 170,000 people. The rest comes from wells.
Beyond its city limits, Melbourne also supplies drinking water to Melbourne Beach, Indialantic, Indian Harbour Beach, Satellite Beach, Palm Shores, Melbourne Village and unincorporated Brevard County south of the Pineda Causeway. Melbourne also provides wholesale water service to West Melbourne.
City testing of Lake Washington on July 10 found a potentially toxic algae, or cyanobacteria, called Dolichospermum circinale. That means there is a cyanobacteria "that could produce a toxin such as microcystins," Shaniese Alexander, laboratory supervisory in the city’s Public Works department, said via email. "To date, we have not found any cyanobacteria where microcystins has been detected in our source waters."
According to the U.S. Geological Survey, that algae species also is capable of creating saxitoxin, the second most potent natural toxin in the world.
Puffer fish in the Indian River Lagoon have been off-limits to harvest since 2002, after some people almost died after eating the fish contaminated with saxitoxin — a poison 1,000 times more lethal than cyanide. At least 28 people got sick in 2002 and 2003 after they ate puffer fish caught in the Titusville area, leading to a permanent state ban on harvesting the fish.
"Any potentially toxigenic cyanobacteria is removed during our treatment process," Mall said.
Large patches and streaks of green algae drifted near the lake's shores Thursday and Friday.
"It was like kayaking in pea soup," Bill Zoby said of taking water samples from the lake Thursday. He's on the nonprofit St Johns Riverkeeper Headwaters Advisory Council. "The gas from the algae was bubbling up and giving off awful smells."
"I am still coughing, itchy eyes and a sore throat from the gases," Zoby said Thursday.
Winter and spring rains and record summer heat set the stage for a witch's brew of algae blooms in the lake this month. Rains pulse in the nitrogen and phosphorus from feeds off farm and residential fertilizers, leaking sewage.
The recent city testing ruled out a toxic blue-green algae, called microcystis, that is linked with short and long-term health risks, such as liver disease. The toxin the algae emits, microcystin, shut down Toledo's water supply or a few days in 2014 and has for years occasionally nagged at Melbourne and other Florida utilities that tap lake or river water. The algae commonly blooms in Central and South Florida, and is toxic to fish, plants, invertebrates and mammals, including humans.
The toxin can magnify in mussels, crayfish, fish and crops irrigated with contaminated water.
Microcystin ingestion can cause diarrhea and abdominal cramps. Swimming in water where the toxin is present can cause rashes. Microcystin has been linked with liver cancer in lab mice, but its long-term effects on humans are less certain.