Toxic Algal Blooms: Danger Ahead

Dr. Larry Brand has spent a professional lifetime analyzing South Florida waters, researching a loosely related group of ancient organisms lumped as algae, which produce the oxygen without which the sea and freshwater would be lifeless. More than pure science is involved.

Whether one-cell dinoflagellate or the dense Sargassum seaweed washing up on the beach, algae bloom like plants. Algal

Dr. Larry Brand, professor of marine biology and ecology, Univ. of Miami Rosenstiel School of Marine and Atmospheric Science, Feb. 21, 2019 (Key News/Nancy Beth Jackson)

blooms are nothing new. Spanish conquistadors encountered them in the 1500s. But in a recent Citizen Scientist lecture, Brand cautioned that the notorious Red Tide and blue-green algae blooms as thick as guacamole are out of control, proliferating, lasting longer, impacting the economy more and producing toxins that sicken and kill other creatures.

So far, Key Biscayne has escaped the worst of it.

“In Key Biscayne we have some of the most pristine waters, because Biscayne Bay has a wall of limestone filtering,” he said, quickly adding the bad news is that unstable ocean currents, global warming and agricultural runoffs may be changing that. [NOTE: While toxic blooms have been rare and seldom seen locally, elevated levels of enterococci bacteria – a fecal contamination indicator- have led to health department advisories and closure of Key Biscayne beaches recently]

The dangers Red Tide presents have been well publicized since the blooms started making headlines in the 1980s — just about when Brand, with a Ph.D. from Woods Hole Oceanographic Institution, arrived as a phytoplankton ecologist at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science.

Fish, birds, sea turtles and manatees die dramatically. Dolphins evidence brain damage. Pets and livestock are at risk. Short-term, humans suffer asthma attacks, bronchitis, pneumonia, skin rashes, diarrhea, vomiting, dizziness, dry coughs and headaches. Although hospital visits for breathing complications or after eating contaminated shellfish increase during blooms, acute toxicity is rarely fatal for humans.

Long-term toxicity, however, is only beginning to be explored.

Experts have nicknamed Red Tide toxins the “good” toxins because bad smells, polluted waters, dead fish or stinging eyes alert you to the danger and tell you to flee the beach. More insidious is BMAA, an amino acid and neurotoxin that cyanobacteria produce in harmful algal blooms. BMAA may not manifest damage until years later and may be linked to Alzheimer’s, ALS and Parkinson’s, as the research of Dr. Paul Allen Cox suggests.

Toxic blue green algae can be found in freshwater ponds and lakes across the country, but in Florida it is most common in Lake Okeechobee, spreading to the Gulf of Mexico via the Caloosahatchee River and to the Atlantic Ocean via the St. Lucie Estuary when federal water managers lower the lake’s level during the rainy season. Brand has also been moderating “a perfect storm” of algal bloom in Florida Bay, where nitrate runoff from agricultural land around the lake meets up with phosphates originating in the rich deposits of Bone Valley mining in Polk County.

While much still remains to be learned about toxic algal blooms, how to attack them ends up being a political question, because the problem is man, not nature. Brand points to the correlation between toxic bloom growth and the expansion of sugarcane agriculture, cattle farming, manicured subdivision lawns and septic tanks.

“If you double the amount of nutrients, you double the amount of algae. We have to limit the amount of nutrients released into our waterways,” he said a few days later at a premier screening at Rosenstiel of “Changing Seas: Toxic Waters,” a new episode in the South Florida PBS-produced environmental series in which he is featured.

In his latest research, Brand is venturing beyond the waters into the air, learning new ways to measure an even more frightening proposition: that toxic algal particles can go airborne, posing a health threat great distances from the original bloom.

For now, there is no advisory of toxic bloom danger in the neighborhood, but Brand is playing it safe. Because of his research, the scientist no longer eats pink shrimp, blue crab, oysters and bottom-feeding fish from Florida Bay.

WANT TO KNOW MORE?

• Watch the new “Changing Seas: Toxic Waters” episode on WPBP2 June 19 or June 26 from  8-9 p.m.

• View Changing Sea Episode 902: “Toxic Sources and Solutions” (2017), which also features Dr. Brand.

• Binge watch the long-running environmental series.