Algal blooms, areas where an abundance of algae growth has occurred, are becoming increasingly common in Lake Erie. Generally, algae are not harmful at all, but rather an important component of fresh-water ecosystems. Harmful algae blooms are so called because they deplete the oxygen in the water and block sunlight — two things that other organisms need to live. They can occur in marine, estuarine, and fresh waters. In the last few years, large algal blooms have been taking up residence in the western end of Lake Erie, and bring with them many issues.
In the 1960s and ‘70s, large algal blooms in Lake Erie led to the declaration that the lake was “dead”. However, the algal bloom that began in July 2011, peaking in early October of the same year, was more than three times larger than the blooms of the ‘60s and ‘70s. The bloom covered approximately 5,180 square km (2,000 square miles) and was composed of almost entirely toxic blue-green Microcytis algae.
A research team at the University of Michigan believes that the 2011 algal bloom in Lake Erie was caused by a combination of weather conditions, in turn caused by climate change and farming practices. Donald Scavia, director of the University of Michigan’s Graham Environmental Sustainability Institute, believes that the weather conditions that added to the creation of this bloom were the intense spring rainstorms of 2011, which are only predicted to worsen every year due to climate change. The duration and intensity of these rainstorms led to increased agricultural runoff. The University of Michigan research team reported record-breaking levels of phosphorous, a nutrient in crop fertilizers that stimulates widespread algae growth, in the western end of Lake Erie.
This phosphorous came from the agricultural land surrounding Ohio’s Maumee River basin, the primary tributary to western Lake Erie. Since the 1990s, no-till farming methods have increased, which use large amounts of dissolved reactive phosphorous (DRP), an algae growth stimulant easily washed away by heavy rainstorms due to its presence in upper surface soil fertilizer. Runoff from farmland in the Maumee River watershed will continue to help trigger large algal blooms in Lake Erie until alternative farming methods are incorporated.
Michael Moore, a professor of environmental economics at the University of Michigan, believes that the emphasis on producing corn for ethanol production, as well as the trend in declining acreage reserved for conservation purposes in the Midwest, are likely to exacerbate the problem. Per Moore, part of the solution will have to be rethinking the emphasis on corn production for biofuels, since phosphate-based fertilizer is most commonly used on corn. Other factors that the University of Michigan team considered were land use, agricultural practices, precipitation, temperature, wind, lake circulation, and surface runoff. Algal blooms bring negative impacts to both humans and wildlife, such as strong smells, clogged boat motors, reduction in fish populations, and the formation of low-oxygen “dead zones” where the majority of aquatic organisms cannot survive. The Great Lakes Echo cites similar negative impacts such as food web disruption, suffering fish populations and fisheries, the expansion of Lake Erie’s dead zone, and changes in water chemistry.
There are heightened concerns for the development of the Lake Erie algal bloom in the upcoming summer. A long-range forecast provided by AccuWeather shows an active severe storm season in the Great Lakes region through May and June of 2013. Per the University of Michigan team’s recommendations, the best bet for decreasing the size and harmful effects of the algal bloom in Lake Erie would be to work with the farmers near the Maumee River basin to help them to find alternatives to the high phosphorous fertilizers they use, and to follow U.S. Environmental Protection Agency (EPA) recommendations for lowering carbon emissions.
