Urban ichthyology: changes in the fish community along an urban-rural creek in Indiana.

ABSTRACT. We collected 39 species of fish from 10 sites along the East Fork of White Lick Creek in Marion and Hendricks counties, Indiana from May through August 2002 in order to quantity stream quality prior to the start of construction on Interstate Highway 70. These included 10 families, with I species each of Lepisosteidae, Clupeidae, Poeciliidae, Atherinidae, Cottidae; 2 species of Ictaluridae; 4 species of Percidae; 6 species of Catostomidae; 9 species of Centrarchidae; and 13 species of Cyprinidae. The most abundant species we encountered were: spotfin shiner (Cyprinella spiloptera), silverjaw minnow (Notropis buccatus), sand shiner (N. stramineus), bluntnose minnow (Pimephales notatus), striped shiner (Luxilus chrysocephalus), central stoneroller (Campostoma anomalum), largemouth bass (Micropterus salmoides), creek chub (Semotilus atromaculatus), johnny darter (Etheostoma nigrum), fathead minnow (Pimephales promelas), rainbow darter (Etheostoma caeruleum), bluegill (Lapomis macrochirus), and the orangethroat darter (Etheostoma spectabile). We documented eight new county records for Hendricks County and one new county record for Marion County. Species richness, abundance of fish, and a modified Index of Biological Integrity for the seining sites were all positively correlated with distance downstream from Indianapolis. A trend toward greater fish abundance was also recorded with increasing distance from Interstate Highway 70. Results suggest that urbanization of Hendricks and Marion counties has had a negative impact on the quality of the East Fork of White Lick Creek.

Keywords: Fish, fish distribution, Indianapolis International Airport, Index of Biological Integrity, urbanization, urban ecology

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During the 1990s, urban ecology in North America graduated from being a fledgling science into an important ecological subdiscipline (Matson 1990; McDonnell & Pickett 1990; McKinney 2002). Much of the initial focus of this discipline was targeted at demonstrating patterns in species richness along strong urban to rural gradients. These gradients often ran from the downtown sections of major cities to pristine areas. Two patterns were repeatedly demonstrated along these gradients: urban areas harbored fewer species, and a greater percentage of those species were exotic (Limburg & Schmidt 1990; Blair 1996; Blair & Launer 1997; Germaine & Wakeling 2001; McKinney 2002). This focus is now changing to one of understanding how urbanization causes these patterns, and how urbanization impacts behavioral and physiological aspects of biology (Denys & Schmidt 1998; McKinney 2002). In addition to focusing on other aspects of biology, there remains a need to determine if the two classic species diversity patterns hold for shallower gradients (Germaine & Wakeling 2001), and a need also exists to apply these patterns toward developing management tools such as buffers to protect biodiversity in developing areas (Blair 1996; Denys & Schmidt 1998; Germaine & Wakeling 2001; McKinney 2002). Our study focuses on a gradient that ranges from subdivisions and commercial properties at the edge of Indianapolis to remnant forests buried in an agricultural matrix. In addition, this study examines whether the green space created by efforts to conserve the Indiana myotis (Myotis sodalis, a federally-endangered bat) is also an effective conservation tool for local fish communities.

This study has four goals. First is to establish stream baseline information as the Indianapolis International Airport (IIA) and its surroundings continue to develop. Of particular concern is moving a 489 m linear section of the East Fork of White Lick Creek during construction of the Six Points Interchange of Interstate Highway 70 (I-70). This goal was accomplished by surveying 10 sites along the East Fork of White Lick Creek from Indianapolis (Marion County) south into and through southwestern Hendricks County, Indiana. Second, as a result of this survey this paper documents new county distribution records of fish from both Marion and Hendricks counties. We collected one new county distribution record for Marion County, where previous researchers (Gammon 1975; WAPORA 1978; Kingsley 1983; Whitaker et al. 1987; Stahl et al. 1997) had documented 72 species of fish. We also collected eight new records for Hendricks County, which has traditionally received little attention from collectors.

In addition to surveying the stream, we also wanted to examine the impacts of development on the local fish communities and to determine the value of the bat conservation areas for conserving fish. Stahl et al. (1997) examined the impact of the Indianapolis International Airport on the East Fork of White Lick Creek, but the results of their study suggested that Indianapolis itself maybe a greater source of disturbance than the airport. Thus we examined changes in species richness of fish, fish abundance, and the Index of Biological Integrity (an index of stream quality) with increasing distance from both I-70 and the Indianapolis metropolitan area (set at the junction of the stream and US Highway 40). Finally, we used the results of these distance analyses to infer how successful conservation efforts aimed at bats were at protecting fish.

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