Ecosystems_of_Nw_Indiana

The area of Northwest Indiana and the Great Lakes is home to one of the world’s most incredible ecosystems. Carved out by glaciers during the last ice age, the Great Lakes contain nearly 20% of the earth's fresh water while the basin supports 1/10th the population of the USA and 1/4 of the population of Canada. The wealth of water and the glacially-sculpted landscape of the lake basin combine to support a tremendous abundance and diversity of life forms. Biological diversity, or bio-diversity, is the total range of life on our planet or in a given ecosystem. This paper looks into the history and ecology of the area, as well as at those human activities that place its bio-diversity at risk. The network of state and provincial Natural Heritage programs has identified 131 elements within the Great Lakes basin that are critically imperiled (22), imperiled (30), or rare (79) on a global basis. Of these elements 100 are individual species (49 plants, 21 insects, 12 mollusks, 9 fish, 5 birds, 3 reptiles, 1 mammal). Of the 131 elements of global significance, nearly half (47%) occur exclusively or predominantly within the basin, or have many of their best examples here. The global existence of these species depends upon their survival in the Great Lakes basin. They define the unique biological character of the Great Lakes ecosystem and underscore the importance of preserving its biological diversity. History When explorers first entered the basin in the 16th century, there were an estimated 60,000 to 117,000 Native Americans residing around the lakes. They lived throughout the basin, hunting, fishing and raising crops such as corn, squash, beans and tobacco. They lived together in small bands, and moved on when the resources became stressed. The first permanent settlers in the area were attracted by the plentitude of fur-bearing animals. In order to protect the fur trade, a series of forts and settlements were built on the channels that connected them to each other. To support the growing cities, a timber industry was born and by the 1840s, commercial logging which had begun in Canada had spread to Michigan, Minnesota and Wisconsin. The early loggers initially harvested the virgin white pines of the basin, these trees could reach 200 feet in height. After exhausting the pines, they turned their attention to other species, such as the maples, oaks and walnuts. Also by the mid-1800s, all of the land available for agriculture in the basin had been settled. The clearing of the Great Lakes watershed during settlement was the initial and massive human stress on the ecosystem. Vegetation was removed, the stream banks were trampled and the stream bottoms disrupted by floating timber sent downstream to the lakes. Any rain that fell drained over the ground surface as run-off, destroying fish-spawning habitats with the layers of sediment it carried. Where the land was converted for farming, wetlands were lost, forests were burned and prairies were plowed under. As cities began to spring up at the mouths of rivers, canals were cut to provide cheap transportation. By 1825, the Erie Canal had linked the Hudson River and Lake Erie, and the Lachine Canal allowed the worst rapids on the St. Lawrence River to be by-passed. Other canals, such as the Miami and Erie Canal, had linked the Ohio River to Lake Erie and in 1829, the Welland Canal had bypassed Niagara Falls, joining Lake Ontario to the rest of the lakes. By connecting formerly separated water bodies, these canals allowed for growth of a Great Lakes shipping industry. Along with this growth was also ushered in the invasion of non-native species. The canals them selves, and the ships that traveled them allowed species such as the alewife and the sea lamprey to enter the system and compete with native species. The fish of the Great Lakes were an important resource to the Native Americans who first inhabited the basin, and were also valued by the Europeans who followed. Commercial fishing began on the lakes around 1820 and increased until the peak years of the late 1800s. Records show that approximately 147 million pounds of fish were commercially harvested in 1889 and 1899. The commercial fishery began to decline during the 1950s in response to human-induced pressures such as introductions of exotic species, over-fishing, the loss of habitat, and pollution. Industrial Waste The waste products generated by the growth of human population and industrial activity it brought created the second major system-wide stress placed on the Great Lakes basin. As the cities grew, manufacturing became an increasingly important economic force in the basin. Iron and steel manufacturing made efficient use of iron ore from Minnesota, limestone from quarries throughout the basin, and coal from the nearby Appalachian plateau. These industries were further facilitated by the cheap cost of transporting large quantities of material by water. Today some of the world's largest concentrations of industrial capacity are located around the Great Lakes and the basin remains the center of both U.S. and Canadian paper, steel, and automobile industries. Human use has adversely impacted the basin ecosystem. In the last 20 years, much has been done to stem the input of nutrients and toxic chemicals into the basin, initiating a rebound in the health of the ecosystem. However, certain past human activities continue to pose threats to the maintenance of biological diversity in the Great Lakes basin. This legacy of industrial waste is the main reason the U.S. Environmental Protection Agency considers this area to have the greatest concentration of environmental problems in the Midwest. In NW Indiana alone, the EPA has found eight Superfund sites, 206 C.E.R.C.L.I.S. sites, and eight Indiana state clean up sites. The largest waste site in this area is the Indiana Harbor and Ship Canal. This canal has not been dredged since 1972 because the Army Corps of Engineers and the EPA cannot agree on what to do with the 3.5 million cubic yards of toxic sediment which must be removed. Below is map showing current and past waste sites for the area: Human activities have altered and will continue to impact the Great Lakes ecosystem and the biological diversity it sustains. To protect this bio-diversity, the ecological processes that sustain key elements need to be safeguarded. Stressors which threaten those processes must be identified, evaluated and then addressed. The health of the lakes and their biological diversity is directly related to the health of each component of the ecosystem. Likewise the lakes are adversely affected when disturbances occur in one of the systems. For example, alterations in the upper watershed can impact the entire lake ecosystem. When a forest is cleared, not only is the physical structure of the terrestrial ecosystem altered, the tributary streams, coastal areas and the open lake can also be affected. When vegetation is removed near a tributary, precipitation is allowed to run off directly into the river or stream, causing flows in these streams to increase much more quickly (after rainfall). This run-off also picks up more soil than it otherwise would, so sediment in the tributary will be increased. The increased sediments can destroy the habitat required by fish and insect species and can prevent the spawning of fish who spend most of their lives in the open lake. These sediments can also accelerate the formation of sand bars and blockages at river-mouths, altering nearby coasts. Human land use, both historic and current, has altered and will continue to impact the Great Lakes ecosystem and the biological diversity it sustains. The reasons for protecting this biological diversity are numerous, but they generally fall into four major categories; 1.) Loss of diversity generally weakens entire natural systems. Healthy ecosystems tend to have many natural checks and balances. Every species plays a role in maintaining this system. When the system is simplified by the loss of diversity, it becomes more susceptible to natural and artificial stresses. 2.) Biological diversity represents one of our greatest untapped resources. Furthermore, every species is a potential source of human medicine. 3.) Humans benefit from natural areas and depend on healthy ecosystems. The natural world supplies our air, our water, our food, and supports human economic activity. 4.) Species and natural systems are intrinsically valuable. The other 3 reasons have focused on the benefits of the natural world to humans, but all things possess intrinsic value simply because they exist. The people of the Great Lakes Basin must become aware of the greatness of diversity the area offers to wildlife, how that diversity is beneficial to humans, and why it must be preserved. By learning of past mistakes, and by cleaning up some past problems, the future of bio-diversity in the area remains strong. BIBLIOGRAPHY ______________________________________________________________________ Engel, Ronald J. Sacred Sands; The struggle for Community in the Indiana Dunes, Wesleyan Univ. Press, CT, 1983. Franklin and Schaeffer, Duel for the Dunes: Land Use Conflict on the Shores of Lake Michigan, University of Illinois Press, IL, 1983. Nature Conservancy Great Lakes Program. 1994. The Conservation of Biological Diversity in the Great Lakes Ecosystem: Issues and Opportunities. University Center, Mich.: Consortium for International Earth Science Information Network (CIESIN). PAHLS Inc. 1993. The Environment of Northwest Indiana: Contrasts and Dilemmas, A Special Report. Pahls, Inc. Valparaiso, IN.