Association of State Wetland Managers - Protecting the Nation's Wetlands.

Salameander: Drinking Water or Algae Soup? Land use, climate change, wetlands, and the color of water

Salameanderby Peg Bostwick, ASWM

The drinking water crisis in Toledo, Ohio – resulting from toxins in the water supply produced by blue green algae in Lake Erie – has received a lot of attention in the national news.  Although these reports are compelling, there does seem to be some confusion about whether the bloom was “natural” or human induced, and whether the causes are known or unknown.  A number of news reports called for more research.  For those who live in the Great Lakes region, the need for action is urgent.  Research is good, but delay is not, and another study may be the last thing we need.  We know what needs to be done. The International Joint Commission (IJC) – which represents the interests of both the U.S. and Canada on issues related to the Great Lakes –produced a thorough report this year – A Balanced Diet for Lake Erie: Reducing Phosphorus Loading and Harmful Algal Blooms.


Blooms of blue green algae – including microcystis which produced the toxins in Toledo’s water supply – are most certainly natural phenomena, but the sheer size and increasing frequency of blooms in Lake Erie are largely the result of human actions. These blooms thrive on dissolved reactive phosphorus concentrations in the lake which have increased as a result of agricultural and, to a lesser extent, urban runoff and pointsource discharges.

Lake Erie is by nature the shallowest and most biologically productive of the Great Lakes – especially the western basin – and it also receives the lion’s share of phosphorus from agricultural and urban sources.  Here are some facts gleaned from multiple sources listed at the end of this post:

  • The Detroit River contributes about 90% of the water supplying the western basin of Lake Erie – including the flow from all of the upper Great Lakes as well as urban contributions from the Detroit area – but only about half of the phosphorus load.  By contrast, the Maumee River, which flows through an agricultural area of Ohio, contributes 5% of the water and almost 50% of the phosphorus load.
  • More than half of the phosphorus loading from the entire Lake Erie watershed is from agricultural sources.
  • According to calculations made by the Environmentally Concerned Citizens of South Central Michigan, based on data from Michigan and Ohio, confined animal feeding operations contributed 3,670,841,070 pounds of liquid and solid manure to the River Raisin and Maumee River watersheds in 2013.

sal88142As the average temperature of the Great Lakes has increased as a result of climate change, algae blooms have exploded.  While climate change may not be the root cause of the bloom, increasing temperature combined with increased rainfall and nutrient runoff have certainly exacerbated it.  The impact of invasive zebra mussels on the ecology of the lakes has also contributed to the problem.

Although the problem is massive, it is also preventable. Solutions exist, but they require significant action on multiple fronts.  The IJC report includes 16 specific recommendations to address both urban and rural sources of nutrient runoff that will be familiar to anyone who has studied eutrophication and the means to protect our nations’ waters.  Some require international policy changes, while others can be readily implemented by individual property owners. For example, reduction or elimination of the spreading of manure on snow and frozen ground, which would greatly reduce spring nutrient loading.

What Does This Have To Do With Wetlands?

As with many issues related to water, wetland protection and management is one ingredient in a much larger whole, and wetland managers can make a definite contribution to solving the problem.  The IJC report notes that about 80% of Lake Erie’s coastal wetlands have been historically altered or destroyed, degrading both habitat and water quality.  However, extensive restorable areas remain: some 157,000 acres on the U.S. side of the lake alone according to a study by The Nature Conservancy. The IJC recommendations include the use of restored or engineered wetlands to reduce phosphorus loading from urban runoff, as well as in agricultural management.  Ray Stewart and Bill Mitsch of the Ohio Wetlands Association have also noted the potential for establishing wetland buffers between agricultural fields and Lake Erie.

Public Trust or Ugly Politics

sal88143It has been pointed out that the Great Lakes belong to our citizens, and that public trust should mandate protection of the quality of these waters for drinking, fishing, and other uses.  Laws like the Clean Water Act are intended to achieve those goals.

Unfortunately, currently proposed rules developed by federal agencies in response to Supreme Court decisions regarding the reach of the Clean Water Act will formalize reductions imposed by the Supreme Court in the protection for “isolated” wetlands. The same wetlands that can trap phosphorus and other pollutants and prevent them from reaching vulnerable public waters, like Lake Erie.  Another rule already set in place by the EPA and the Corps of Engineers expands exemptions for agricultural actions that impact wetlands.  These changes are directly counter to what is needed to protect drinking water in Lake Erie and elsewhere.  We can hope that these proposed changes will ultimately be tempered, and that states (and provinces) will step up where national protection measures fail.

Even more ironic may be that Michigan’s Attorney General Bill Schuette recently joined a legal action by the American Farm Bureau Federation against the USEPA, seeking to invalidate a TMDL developed by state and federal agencies to support the cleanup of Chesapeake Bay – that is, a plan to address the same type of water quality problems that produced toxic drinking water in Toledo. Where waters serve multiple states, and are impacted by multiple states, federal programs that protect these waters are very much needed.  The message, in short, is that state and federal resource protection programs need to work in sync, as planned, to protect critical water resources.

A Fundamental Need for Water, and the Urgent Need for Action

Drinking water is one of our most basic human needs.  One would expect the crisis in Toledo to spur action to address the problem.  But, given the multiple responses that are needed from governments, farmers, conservationists, and others, it is up to all of us to initiate that action. If we do not, then it is certain that we will face this and related problems again, and that drinking water will be compromised elsewhere.  The IJC has defined the steps that are needed for Lake Erie. We just need to implement them.


More reading:

For a link to an IJC comment on the bloom and their report on harmful algal blooms, click here.

For remote images of the Lake Erie bloom from NASA, click here.

For a CBC news article, Lake Erie’s algae explosion blamed on farmers, click here.

For information about the amount of manure discharge from CAFO’s in the Lake Erie watershed from U.S. sources, click here.

For a copy of the American Farm Federation brief in a suit against the U.S. EPA regarding the Chesapeake Bay TMDL, joined by the Michigan AG and others, click here.

For a statement from the Ohio Wetlands Association addressing the Lake Erie algal bloom, click here.

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