Academic journal article The American Midland Naturalist

Historical and Current Environmental Influences on an Endemic Great Plains Fish

Academic journal article The American Midland Naturalist

Historical and Current Environmental Influences on an Endemic Great Plains Fish

Article excerpt

ABSTRACT.-

Native fishes of the Great Plains are at risk of decline due to disturbances to physical habitat caused by changes in land and water use, as well as shifts in species assemblages driven by the invasion of introduced species with the loss of natives. We used historical and current fish assemblage data in conjunction with current habitat information to assess these influences on an endemic Great Plains stream fish, the plains topminnow (Fundulus sciadicus). Of the 31 sites where the plains topminnow occurred historically (1939-1940), it was found in only seven of those sites in 2003-2005. Our results demonstrate a shift in fish assemblage over time that coincides with the loss of plains topminnow. Changes in fish assemblages were characterized by increases in occurrence of exotic, invasive and generalist species with declines in occurrences of native fishes. An information theoretic approach was used to evaluate candidate models of current fish assemblage and physical/chemical habitat on the presence of the plains topminnow. Candidate models that included both instream habitat (e.g., vegetation coverage, undercut banks) and the native fish species assemblage are important to predicting presence of the plains topminnow within its historic range. Conservation of Great Plains fishes including the plains topminnow will need a combination of habitat protection and enhancement.

INTRODUCTION

Freshwater fishes are at risk of decline in range and local abundance resulting in extirpation and eventual species loss due to widespread anthropogenic disturbances. Human impacts are the primary cause of decline and extinction of fishes (Miller et al., 1989; Williams et al., 1989; Richter et al., 1997; Ricciardi and Rasmussen, 1999). Disturbance to physical habitat (e.g., riparian vegetation alteration, impoundments; German and Karr, 1978; Jones et al., 1999; Marchetti and Moyle, 2000; Quinn and Kwak, 2003), water quality (e.g., pollution, sedimentation; Tsai, 1973; Bonner and Wilde, 2002) and the introduction of nonnative species (Soule, 1990; Rahel, 2002) have resulted in fish assemblage shifts, decreased native species diversity, community homogenization, range reduction and extinction.

The Great Plains, one of the largest biomes in North America, has been subjected to widespread disturbances to both its terrestrial and aquatic resources. The native grasslands ( 162 million ha) of the Great Plains are one of the nations most threatened ecosystems with losses of up to 99.9% in range (Samson and Knopf, 1994). However, the region's aquatic ecosystems have received less attention compared to other regions (Matthews, 1988).

The conversion of the Great Plains to agriculture and replacement of native terrestrial grazers (i.e., bison) with domesticated livestock have increasingly affected prairie stream ecosystems and fish assemblage structure by increasing siltation and decreasing foraging efficiency of native species (Bonner and Wilde, 2002) and decreasing instream habitat diversity through alteration of riparian habitat and channel morphology (Gorman and Karr, 1978; Jones et al., 1999). The change in physical habitat due to impoundments has also been associated with assemblage changes, usually causing declines in native lotic species and diversity, while nonnative lentic fishes increase in abundance and range (Minckley and Deacon, 1968; Winston et al., 1991; Patton and Hubert, 1993; Marchetti and Moyle, 2000; Minckley et al., 2003; Falke and Gido, 2006).

The conservation and management of freshwater fish is often difficult. For example, detecting long-term changes in fish assemblages is often problematic because of the lack of historical documentation before alterations to the ecosystem occurred (Matthews, 1988; Fausch and Bestgen, 1997). It is this lack of baseline data for which to evaluate the status of species that creates difficulties in preventing the listing of potential species as vulnerable or in need of conservation (Patton et al. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.