Are green lawns worth the risk of green Lake Erie water and toxic algae? Diane Lewis

Lake Erie algae

(D'Arcy Egan)

As the seasons change on Lake Erie, broad strips of the water's surface turn bright blue-green with floating patches of sludge. The attractive iridescent color belies the danger the algae poses to swimmers and to the many communities that draw drinking water from the lake.

This algae is toxic – and one of its main causes are the fertilizers we use on our lawns. By keeping our lawns green with the use of chemicals, we are hurting ourselves.

The two factors contributing to the rapid escalation of this problem are climate change and increasing amounts of fertilizer.

Climate change has led to warmer springs, heavier rains and more severe storms that wash the fertilizer from both farms and homes into the water. Summer droughts lead to warmer, shallower waters near the shore. The excess nutrients in unusually warm water cause unfettered algae growth.

Once in the water, the algae produces toxins that cause difficulty breathing, digestive problems and rashes when it is ingested, inhaled, and when it comes in contact with skin.

The toxin it secretes also harms the liver and nervous systems if enough is consumed. Researchers have found an increased incidence of Amyotrophic Lateral Sclerosis or Lou Gehrig's disease in people living near lakes with large amounts of blue-green algae.

Even more worrisome, these toxins are not easily removed once introduced. Boiling the water, chlorine, ultraviolet disinfection, and routine filtration does not help. Water districts throughout Ohio have spent millions of dollars to keep toxic algae out of drinking water by installing specialized filters.

But it's not just Lake Erie suffering from these blue-green blooms. Both fresh and salt water are susceptible, and at least 21 states have this problem, including Ohio, New York, Wisconsin, Florida and California. When bacteria degrade the algae, they deplete the water of oxygen, killing fish and creating dead zones.

Regulators have taken steps to hash out a solution. Recently, the International Joint Commission, representatives from the United States and Canada that work together to protect shared waters, recommended regulations to decrease fertilizer contamination of Lake Erie.

Sen. Bill Nelson of Florida has introduced a bill that would expand a federal task force studying the problem and require it to develop an action plan to address both the algae and the resulting low oxygen zones. Sen. Rob Portman of Ohio is a co-sponsor of this bill. But these guidelines alone will not solve the problem.

Fertilizer going into Lake Erie comes from both homes and farms, and the homeowner contribution is significant.

Twelve states, including two in the Lake Erie Basin -- New York and Michigan -- have banned routine use of phosphorus in fertilizer intended for residential use. However, because all of these states have exemptions for starting a new lawn or repairing a lawn, and for replacing a phosphorous deficit, and some have gardening exemptions, phosphorous-containing fertilizers are still sold.

Homeowners can help solve the algae problem and still have beautiful lawns and gardens by embracing the natural life cycle and planting more diverse plants that are part of the natural heritage of our communities. These plants are adapted to thrive with less water and less care. This change does not cost more.

Using organic fertilizer only to replace a nutrient that is lacking, and using it in fall when root growth is strongest and spring rains don't wash it right into the lake, makes a big difference.

Gardeners have an increasing number of good options for plants that are hardy without synthetic chemicals, and many that are drought-resistant, too. Native plants -- that is, plants that occur naturally and were here before the European settlers arrived -- flourish without chemicals or watering, except during severe drought. Native plants also provide excellent habitat for birds and other wildlife.

Many birds and amphibians can only eat insects that require native plants, so native plants not only protect our water supply, but also biodiversity. For instance, endangered Karner Blue butterfly caterpillars only feed on wild blue lupine found in lakeshore dunes.

By working together to grow native plants and not using chemicals on our lawns, we can protect biodiversity and our drinking water from the serious and increasingly common threat of blue-green algae blooms.

Diane Lewis is author of "The Great Healthy Yard Project: Our Yards, Our Children, Our Responsibility" and founder of The Great Healthy Yard Project.