Changes in range-wide distribution of plains topminnow Fundulus sciadicus

Abstract

Globally, riverine fishes are affected by degradation of habitat, stream alterations, lost stream connectivity and introduction of non-native species. The plains topminnow Fundulus sciadicus, a small stream-dwelling fish, currently does not have a federal conservation status in the USA; however, anecdotal reports have suggested its decline for the last 20 yr. Our goals were to evaluate the validity of its reported decline and to determine the current range-wide status of this species. We identified 927 historical sites (1889−1999) of occurrence and compiled recent records or re-visited 667 sites (2000−2010). We found plains topminnow at 189 (28.0%) of these sites. Although Nebraska represented the center of distribution and included 66.7% of all historical sites, plains topminnow were only found at 34.4% of historical sites, with the largest declines observed in the Platte and Republican River drainages. Current sampling efforts in Colorado, Missouri, Oklahoma, South Dakota and Wyoming found similar declines. In Iowa and Kansas, plains topminnow was not found, whereas potential increases in distribution were observed in a single drainage in Minnesota and Wyoming. In addition to our sampling efforts, we repeatedly sampled 40 sites within Nebraska to determine detection probability. Detection probabilities for plains topminnow were consistent at 0.76 ± 0.05 (mean ± SE) among sites that were sampled with a single visit. Further research is needed on the species and the potential threats to its occupation of sites, as no singular cause for decline seems plausible. Observed threats include degradation and loss of habitat and shifts in species assemblages towards generalist non-native species. 16: 235-247, 2012 ditionally, lotic systems are geographically expansive and can be influenced by multiple alterations and disturbances at the same time, which makes determining the primary causes for species decline and loss difficult (McCartney 2002). KEY WORDS: Fundulus sciadicus · Plains topminnow · Fundulidae · Endemic · Decline · Threat Resale or republication not permitted without written consent of the publisher Contribution to the Theme Section 'Endangered river fish: threats and conservation options' OPEN PEN ACCESS CCESSEndang Species ResThe plains topminnow Fundulus sciadicus is en demic to the central United States (Fig. 1) with 2 disjunct populations (Lee et al. 1980). The largest distribution is centered in Nebraska and extends to north eastern Colorado, southwestern Wyoming, southern South Dakota, southwestern Minnesota and Iowa (Baxter & Stone 1995, Weitzel 2002, Rahel & Thel 2004. The second population is centered in Missouri and ex tends from Kansas south to Oklahoma (Pflieger 1997) (Fig. 2). The plains topminnow is currently ranked as globally secure according to the Natural Heritage database (NatureServe 2011). However, all states in the native range, except Oklahoma, recognize some level of concern for plains topminnow. In Iowa and Kansas, plains topminnow is presumed extirpated (Harlan et al...

Development and evaluation of species distribution models for fourteen native central U.S. fish species

“…Impoundments often support non-native species that compete with native species. For example, plains topminnow distribution has been suggested to be negatively influenced by the presence of non-native species such as largemouth bass (Micropterus salmoides) and mosquitofish (Gambusia affinis) (Fischer & Paukert, 2008a;Pasbrig et al, 2012). Impoundments have also been associated with reduced habitat and populations of suckermouth minnow, slenderhead darter, and bigmouth shiner (Quist et al, 2005;Heimann et al, 2007).…”

Experimental analysis of reintroduction strategies to conserve the vulnerable plains topminnow Fundulus sciadicus in Nebraska

“…Prior to reintroduction efforts, we sampled the local fish assemblage using 3-pass depletion backpack electrofishing with block-nets. This assessment, paired with recent range-wide sampling efforts (see Pasbrig et al 2012), confirmed that plains topminnow were not present at reintroduction sites.…”

Large-scale dispersal patterns and habitat use of plains topminnowFundulus sciadicus: implications for species conservation

“…Plains topminnow is a habitat specialist that occurs in widely distributed, isolated, and dynamic habitat patches characterized by shallow, stagnant water that are especially vulnerable to desiccation by means of prevalent agricultural activities that divert water from the channel or lower the water table (Rahel & Thel 2004;Fischer & Paukert 2008;Pasbrig et al 2012). The isolated nature of plains topminnow populations suggests that stream connectivity may be important to their longterm persistence (Cross & Collins 1995;Pflieger 1997;Rahel & Thel 2004;Pasbrig et al 2012).…”

“…Plains topminnow, Fundulus sciadicus, populations have declined in both distribution and local abundance throughout their native range (Rahel & Thel 2004;Pasbrig et al 2012). Declining water quality and quantity, habitat degradation, population fragmentation, and the introduction of nonnative fishes have resulted in declines of other Great Plains stream fishes (Haslouer et al 2005), and likely influence the persistence of this species (Rahel & Thel 2004;Pasbrig et al 2012).…”

“…Declining water quality and quantity, habitat degradation, population fragmentation, and the introduction of nonnative fishes have resulted in declines of other Great Plains stream fishes (Haslouer et al 2005), and likely influence the persistence of this species (Rahel & Thel 2004;Pasbrig et al 2012). Plains topminnow is a habitat specialist that occurs in widely distributed, isolated, and dynamic habitat patches characterized by shallow, stagnant water that are especially vulnerable to desiccation by means of prevalent agricultural activities that divert water from the channel or lower the water table (Rahel & Thel 2004;Fischer & Paukert 2008;Pasbrig et al 2012). The isolated nature of plains topminnow populations suggests that stream connectivity may be important to their longterm persistence (Cross & Collins 1995;Pflieger 1997;Rahel & Thel 2004;Pasbrig et al 2012).…”