Threats to the Great Lakes
The Great Lakes contain 20% of the worlds freshwater--a finite resource. As water shortages become more frequent and severe across the nation and around the world, it is important to protect the Great Lakes water from being diverted. The Great Lakes Basin Compact is a multistate agreement to promote conservation of the water resources of the Great Lakes Basin. Minnesota, Wisconsin, Illinois, Indiana, Ohio, Michigan, Pennsylvania, and New York and the Canadian provinces of Quebec and Ontario are all part of the agreement. The Great Lakes Basin Compact delineates a border around those cities closest to the Great Lakes and acts to ensure that no Great Lakes water is shipped outside of this region. This agreement, which was signed in December 2005 by the governors of the eight states, came about when a Canadian company announced that it wanted to ship water in tankers from Lake Ontario to Asia. As of January 2008, the governors of Minnesota and Illinois have ratified the compact, creating momentum for the other six states to officially adopt the compact.
Invasive Species in the Great Lakes
More than 160 exotic species have invaded the Great Lakes, threatening to dismantle key components of the Great Lakes ecosystem. The worst invaders have caused substantial damage to fisheries and ecosystem health.
Invasive species threaten not only fisheries and ecosystem health, but also the economy of the Great Lakes region. The well-known zebra mussel, for example, has caused widespread disruptions of water infrastructure and imposed steep control costs. Great Lakes industries and municipalities spent $120 million controlling the zebra mussel in the first five years after they became established in the ecosystem. The recreation and tourism put at risk by invasive species in the Great Lakes region is valued at $15 billion annually. The Great Lakes commercial and sport fisheries, threatened by damages caused by invasive species, are responsible for creating 100,000 jobs.
Some of the most serious threats to the Great Lakes from aquatic invaders include:
Zebra mussels are aggressive filter-feeders that deplete nutrients needed by other organisms in the food web. They also form dense colonies on lakebeds, occupying habitat needed by other species, and have been linked to toxic algae blooms that threaten fish and human health.
Round gobies affect the food web of the Great Lakes by aggressively outcompeting small fish like the mottled sculpin and eating the eggs of larger fish like smallmouth bass. Round gobies are one of the few fish species known to eat zebra mussels. The invasion of the Great Lakes by zebra mussels may have worsened the problem with round gobies.
Sea lampreys attach themselves to fish and drain them of blood and bodily fluids. An adult sea lamprey can kill up to 40 pounds of fish in 12 months. Sea lampreys have led to substantial declines in lake trout, burbot, and lake whitefish in the Great Lakes.
Bighead carp and silver carp (collectively referred to as Asian carp) are large filter feeders that have the potential to deplete zooplankton populations and outcompete fish with high recreational and commercial value, such as salmon and perch. Silver carp have become infamous for their tendency to panic when they hear a boat motor, hurling themselves out of the water and into the path of passing vessels, causing danger for recreational boaters. Asian carp are threatening to invade Lake Michigan.
Quagga mussels are similar to zebra mussels in size and appearance, but thrive in deeper waters, threatening additional lake areas. Quagga mussels have been linked to avian botulism outbreaks that have killed hundreds of loons, grebes, and cormorants.
Potential Impacts of Corn Ethanol in the Great Lakes
Increasing energy costs and policies to reduce dependence on foreign oil have substantially increased the U.S. production of bioethanol as an alternative fuel. In 2007, the Great Lakes region had 39 ethanol production facilities with an additional 28 facilities and facility expansions underway. Despite the possible benefits of of carefully managed biofuel production, corn ethanol manufacturing in the Great Lakes region has environmental and socio-economic impacts that need to be addressed when assessing the benefits and costs of increasing corn ethanol production in this sensitive ecosystem. Some of the environmental consequences include:
- Conversion of agricultural lands to corn production instead of other less profitable crops
- Agricultural monoculture, loss of conservation acreage through the Conservation Reserve Programs [link to Audubon's fact sheet on CRPs]
- Soil erosion and sedimentation
- Water use
- Loading of nutrients and persistent contaminants