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Page 24 ~ Northeastern Region Roundtail chub abundance in the mainstem Green River and associated tributaries has declined since the installation of multiple water development projects beginning in 1902 (Bezzerides and ~ Bestgen 2002). In addition to water development, the introduction of nonnative predators and competitors over the same time period has proven to be detrimental to the roundtail chub (Bezzerides and Bestgen 2002) as have the presence of oil exploration projects within the drainage. Roundtail chub were described as abundant in the Duchesne River as late as 1975 (Holden and Stalnaker 1975) and common in 1982 (Tyus et al. 1982), but have since declined in ~ numbers (Brunson and Christopherson 2003). In the White River, oil exploration projects and the presence of non-natives are the largest problems. Roundtail chub were considered abundant in the White River in 1975 (Holden and Stalnaker 1975), but only relatively common in 1981 (11 of catch; Lanigan and Berry 1981) and 1982 (8-10% of catch; Miller et al. 1982). Flaming Gorge Dam is thought to have impacted roundtail chub at three sites: Willow Creek, Little Hole, and ~ Brown's Park. Roundtail chub were found at these locations in 1962, but not in 1964, 1965, 1966, or 2004 (UDWR unpublished). Detailed information regarding the historical and current status of roundtail chub and associated threats from Division data is found in Table 2-1. Southeastern Region Though accounts of roundtail chub in this region are somewhat rare, recent information suggests that roundtail chub were present, but never abundant in mainstem habitats such as the lower Green, San Juan, and Colorado rivers; present in the Price, San Rafael, and upper Dirty Devil rivers (Tyus et al. 1982, Holden and Stalnaker 1975, Bezzerides and Bestgen 2002); and . abundant in the Dolores River (Bezzerides and Bestgen 2002). Cavalli (1999) suggests that roundtail chub may have been extirpated from the Price River due to low flows in 1977 and 1993, a localized rotenone detoxification problem in 1977, andJorpo1lution-caused fish kills that have occurred in the past 20 years. Current surveys in the Price River seem to support this hypothesis. Although roundtail chub were observed in the San Rafael River during 2005, they were rare. This rarity and the absence of roundtail chub during 2004 surveys may be indicative of a decline in abundance within the drainage (Walker and Hudson 2004). Cavalli (1999) suggests that roundtail chub are slow to re-populate unoccupied habitats; therefore, roundtail chub may not move back into de-watered habitats until many years after habitat is suitable again. Detailed ~ information regarding the historical and current status of roundtail chub and associated threats is found in Table 2-2. Southern Region Roundtail chub were thought to be historically present in the Escalante and Fremont rivers (Bezzerides and Bestgen 2002) and continue to be observed in the Escalante River (Fridell et al. 2004; Morvilius and Fridell 2005). Recent accounts in the Escalante River suggest that nonnatives pose a limited threat and that de-watering, pollution, and disease also likely pose threats to their presence in parts of the Escalante (Mueller et al. 1998). Detailed information ,, regarding the historical and current status of roundtail chub and associated threats is found in Table 2-3.