Paddling on the Wisconsin River is one of the best kept secrets in the Midwest.  The state’s namesake river cuts diagonally across Wisconsin, winding a lazy, sandy path through some of the state’s most stunning scenery on its way to join the Mississippi. One of my favorite features is the sand bars that dot much of the length. These are largely publicly owned and available for picnics and overnight camping on a first-come, first-served basis.  On a beautiful summer weekday, you can pretty much have the river and its sandbars to yourself.

Walking across one of those sand bars recently I noticed crusty blue patches, clearly left behind from times of higher waters. They made me think of spring in Virginia when the pine tree pollen floats on every puddle, but I’d never heard of blue pollen. My paddling partner Denny Caneff, executive director of the River Alliance of Wisconsin, felt pretty certain that I was seeing blue-green algae, bleached of their green pigments as the puddles dried up.

Blue-green algae, which are more appropriately called blue-green bacteria or cyanobacteria, are a naturally occurring and important part of our ecosystem, but have a pretty bad rap because of the noxious impact that they have on recreational lakes and drinking water sources.  When the right combination of growth-stimulating phosphorus, warm temperatures and calm waters get together, cyanobacteria populations explode.  The Wisconsin River has a steady flow and is relatively cool because of the groundwater-fed streams that feed into it, so bacterial blooms are kept to a minimum.  But when high waters recede, the nutrient-rich puddles left behind on sand bars quickly warm up in the sun and become incubators for bacterial growth.  The cyanobacteria turn the water a shockingly green, almost unnatural, color.  As it turns out the “unnatural” look is because of the phycocyanins, natural pigments with “a characteristic light blue color” according to my go-to resource, Wikipedia. That’s what I was seeing on the sand bar that warm, August day.

Cyanobacteria have launched into newsrooms and public hearings because of their recent show-stopping impact in Toledo, Ohio.  Lake Erie, Toledo’s water source, has long been experiencing disruptive “blooms” (a deceptively nice-sounding use of the word), but the City of Toledo Public Water system has always been able to clean the water sufficiently to meet regulatory requirements and customer expectations.  But not this time.  The ban lasted nearly three days, and customer confidence has undoubtedly been shaken for much longer than that.

Many prognosticators are comparing this event to the late-‘60s burning of the Cuyahoga River, aflame with pollution from Cleveland’s thriving industries. That incident is credited with energizing public officials to finally be able to pass the Clean Water Act in 1972, and the hope is that Toledo’s pain will be enough to rally our nation to clean up its act on phosphorus, which has long been getting into our waterways from lawns, road surfaces, sewage treatment facilities, septic tanks and, of course, farm fields.

Let us not fool ourselves into thinking that this is a one-time crisis, isolated to Toledo or Lake Erie.  The Lake Erie problem, which has been going on for 10-12 years, is mirrored in freshwater lakes throughout. People have been writing about the problem for some time, and advocacy groups have been trying to get attention on this for just as long.  Health officials are starting to learn that the problem may be worse than we think: There is evidence that very low levels of exposure over a lifetime contributes to degenerative neurological diseases such as ALS.

No one wants to swim or fish in water coated with brilliant-green scum, but there’s more to this than squeamishness.  Despite being small, “simple” organisms, cyanobacteria have complex life cycles, and complex impacts on our own biology. Though cyanobacteria are complex, some things are easy.  We know that in order to restore confidence in our nation’s water we need to get back into right relationship with phosphorus.  That means restoring wetlands, decreasing fertilizer use on lawns and farms, recovering more phosphorus from sewage treatment plants, and increasing agricultural soil health so that fewer nutrients wash out into our waters.  We know what to do.