Lake Erie's Vulnerability to Toxic Blooms is Worse Than We Thought

Lake Erie, like a good portion of US waters, has always been vulnerable to large harmful algae blooms (HABs). However, a new study has revealed that this vulnerability has been on the rise in recent years, making it harder for officials to prevent threats to public health.

The study, recently published in the journal Water Resources Research, details how Lake Erie has become increasingly susceptible to large blooms of toxin-producing cyanobacteria since 2002, paving the way for a greater likelihood of more water quality crises like the drinking water problem that occurred in Toledo, Ohio earlier this year.

Investigations have left experts to believe that the Toledo crisis was largely due to large amounts of phosphorus fertilizer washing off croplands and flowing into western Lake Erie. This phosphorous, along with elevated water temperatures and silty conditions, encourage the rapid growth of cyanobacteria, leading to HABs.

That's why officials are now making moves to cull phosphorous exposure. However, "Our results suggest that current phosphorus loading targets will be insufficient for reducing the intensity of cyanobacteria blooms to desired levels, so long as the lake remains in a heightened state of bloom susceptibility," the new study's lead author, Daniel Obenour, explained in a recent release.

According to the study, the amount of phosphorous is still the primary factor that drives HABs, but the amount of the acidic compound needed to trigger a bloom in the lake appears to be steadily declining. Meanwhile, the size of late-summer blooms has steadily increased since the mid-1990s.

Obenour and his colleagues suggest that the presence of invasive quagga and zebra mussels could be to blame for exacerbating the situation, as their growing dominance in the Lake Erie ecosystem could be disrupting the natural phosphorous cycle of the lake. These mollusks are also feeding on types of algae that are typically good for the lake, but utterly ignoring cyanobacteria - leaving them to wreak havoc on water quality.

Still, more research is needed to see if this theory is correct. Meanwhile, Hugh McDiarmid Jr., spokesman for the International Joint Commission, recently told The Associated Press that any action to cull phosphorous levels is good action.

"While analyzing all of the factors involved in the algae threat is important," he said, "it is imperative to act now on the factors we can influence."