Habitats and Ecological Communities of Indiana: Presettlement to Present

7. Aquatic Systems

114 Aquatic Systems 7 Clean fresh water is not only important to fish and wildlife, but a requirement for human survival. At the time of European settlement, Indiana was blessed with an abundance of fresh water and freshwater habitat (Figure 7.1). The state is partly bounded by major water bodies. Lake Michigan forms about 40 mi of the northwest border, the Wabash River (the nation’s longest un-dammed river, flowing for a total of 510 mi) forms the western boundary of most of the southern half of Indiana, and the Ohio River forms the entire southern boundary, joining the Wabash at the lowest (345 ft above sea level) and most southwestern point in the state (Map 7.1). The earliest written descriptions of Indiana’s lakes, rivers, and streams remark on the clear water and the abundance and diversity of fish (McCord 1970). Indeed , the origin of the name “Wabash” can be traced through French and English pronunciations to the Miami Indian word Wah-bah-she-keh, meaning “pure white,” a reference to the limestone river bottom in Huntington County, which is visible through the river’s crystal-clear waters. Robert Cavelier de La Salle is credited with the European “discovery” of the Ohio River in 1669–1670. The name “Ohio” is believed to be derived from an Iroquoian word meaning “great river.” However, La Salle interpreted “Ohio” as beautiful river, or la belle rivière (www.ibiblio.org/ eldritch/nhb/S2.HTM). Several of Indiana’s interior rivers, such as the White and Whitewater rivers, still reflect the clarity of Indiana streams. All of Indiana ’s earliest settlements (Ouiatenon, Chippecoke, and Kekionga) were established on major rivers. For the early European explorers and settlers, the major transportation routes were Indiana’s waterways and buffalo traces (McCord 1970). As settlers poured into Indiana, the state’s rivers, streams, and lakes provided food, power for mills, and transportation for moving grains, livestock, timber, and hay to market (McCord 1970). As Indiana was settled by Europeans, the surface waters of the state suffered many impacts that made them unrecognizable to Indiana’s early settlers. As Figure 7.1. Clear, freshwater small river in northern Indiana. Photo by Terry L. Castor. 115 Aquatic Systems the forests were cleared and agricultural fields established , sediments poured into the water, reducing clarity and clogging stream bottoms. Streams were straightened (ditched) to improve drainage, and the tree cover on stream banks was removed. During the nineteenth and early twentieth centuries, Indiana streams received untreated or inadequately treated discharges from industrial and commercial sources and urban sewage. Communities sought to control the natural fluctuations of the rivers and streams. Dams were built to retain water for municipal use or power generation, and levees were built to constrain floodwaters and to secure river bottomland for agriculture. Even the mighty Ohio was dammed, essentially reducing the river to a series of impounded pools, to provide for year-round navigation. These Map 7.1. Streams and rivers by natural region. 116 Natural Habitats alterations, along with the draining of wetlands that attended many of Indiana’s major rivers, had a profound impact on fish and other aquatic-related wildlife populations. Factors Affecting Water Quality Terrestrial habitats are described in terms of vegetative cover (e.g., forest or grassland), connectivity, and patch size. Aquatic habitats are described and defined by different parameters; among these are components that are resistant to change, such as the impacts of drainage history, watershed topography, and stream gradient. Many other factors and environmental conditions interact to impact the quality of aquatic habitat and the various aquatic niches available. Some of these are the amount of vegetative cover in the watershed , the type and amount of anthropogenic discharges , and stream channel or lakeshore modifications . Variations in and modifications of these factors have important impacts on aquatic habitat variables, such as dissolved oxygen (and other water chemistry ), water temperature, water depth, and stream bottom substrate. Indiana’s waters have also been altered by water withdrawals, thermal inputs (hot water discharges ), fish management history, and the introduction of exotic species. Indiana’s aquatic habitats are the result of a shared history with much of the midwestern United States (Gerking 1945; Hocutt and Wiley 1986; Burr and Page 1986). Foremost among the factors that shaped the fish assemblages of Indiana were the natural forces that formed the landscape and the series of glacial streams that provided temporary...