Chicago Tribune (Sunday)

Progressiv­ely more toxic

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Lake Erie’s noteworthy green tinge is the result of a medley of algae and bacteria. Phytoplank­ton, a microscopi­c green algae, is food for small organisms. Cyanobacte­ria, sometimes called bluegreen algae, is actually an aquatic bacteria that captures sunlight for energy and produces oxygen like regular algae, but some also produce toxins that are harmful to humans and animals.

Microcysti­s aeruginosa is the most prevalent cyanobacte­ria found in Lake Erie. But it is just one of roughly a dozen that have collective­ly staked a larger claim since the introducti­on of invasive zebra and quagga mussels in the 1980s.

The fingernail-size shellfish filter copious amounts of water, ravenously eating the beneficial green algae and plankton that feed fish. The mussels don’t consume the cyanobacte­ria, which, in turn, allows it to increasing­ly dominate the bloom.

While every type of cyanobacte­ria doesn’t create toxins, it’s clear that Lake Erie’s annual bloom is becoming progressiv­ely more toxic. Since 2014, federal, state and local agencies have conducted routine water sampling for toxins, with 2019 being among the years when it was most severe.

Scientists are continuing to find new harmful substances produced by cyanobacte­ria, though they don’t fully understand why these bacteria secrete them.

Researcher­s have theories. Some believe the cyanobacte­ria are producing toxins to kill a perceived competitor. Others believe that the bacteria cells produce toxins as nourishmen­t when they are stressed. There is also evidence that links toxin production to the levels of nitrogen (an abundant nutrient also found in excrement) in the water.

No matter the reason, residents of Toledo remain on high alert.

Since the crisis, the Jankowskis store more than a dozen jugs of water in the basement. They’ve had a $3,000 water filtration system installed for their shower and sinks. And they don’t drink from the tap.

Mayor Kapszukiew­icz is trying to erase these kinds of fears. Elected three years after the water crisis, he tries to drink tap water in public whenever possible. He kept the pressure on suburban communitie­s that threatened to bolt the Toledo water system, which would have been a significan­t financial loss for the city. And his administra­tion created an online dashboard showing the safety of drinking water that he intends to retire because it has never dropped below the “Safe” threshold.

There are no federal regulation­s on the amount of cyanobacte­ria toxins that can be in drinking water. But, in the aftermath of August 2014, the Collins Park water treatment plant quadrupled its capacity for carbon activated powder and chlorine, chemicals used to remove these toxins.

Toledo also accelerate­d the constructi­on timeline for a new form of water treatment using ozone, a technique that is much more efficient at destroying cyanobacte­ria toxins. Since the 2014 crisis, the city has also vowed to find an alternativ­e water source.

Before 2014, it could take as long as 12 hours to get test results on water quality. Now, a network of buoys is the first line of defense and produces results almost immediatel­y.

The buoys are equipped with underwater cameras that measure cloudiness and pigment, which signals the severity of the bloom and toxins, according to Ed Verhamme, a coastal engineer for

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