FWS says listing of roundtail chub DPS warranted but precluded
74 Fed. Reg. 32352 / Vol. 74, No. 128 / Tuesday, July 7, 2009 / Proposed Rules
DEPARTMENT OF THE INTERIOR / Fish and Wildlife Service / 50 CFR Part 17 / Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition To List a Distinct Population Segment of the Roundtail Chub (Gila robusta) in the Lower Colorado River Basin
SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 12-month finding on a petition to list a distinct population segment (DPS) of the roundtail chub (Gila robusta) in the lower Colorado River basin as endangered or threatened under the Endangered Species Act of 1973, as amended (Act). The petition (by CBD)also asked the Service to designate critical habitat. After review of all available scientific and commercial information, we find that the petitioned listing action is warranted, but precluded by higher priority actions to amend the Lists of Endangered and Threatened Wildlife and Plants. Upon publication of this 12- month petition finding, this species will be added to our candidate species list. We will develop a proposed rule to list this population segment of the roundtail chub pursuant to our Listing Priority System. Any determinations on critical habitat will be made at that time. SEE ALSO, prior ESA blawg
Roundtail chubs, in the lower Colorado River basin (as pictured above from Bureau of Reclamation) are found in cool to warm waters of rivers and streams, and often occupy the deepest pools and eddies of large streams. They are omnivores, but algae and aquatic insects can be major portions of the diet.
EXCERPT RE: THREATS ANALYSIS: Threats, including water diversions, groundwater pumping, dams, channelization, and erosion-related effects, are occurring that impact both the amount of water available for habitat, as well as the water’s suitability for roundtail chub. Threats from flood control, development, roads, water withdrawal, improper livestock grazing, recreation, and high-intensity wildfire dry up, silt in, physically alter, and chemically pollute habitats of the roundtail chub such that habitats become permanently unsuitable... All of these threats are anthropogenic and can be expected to continue, if not increase, given the predictions for increases in human population expansion in the region... Predation and competition with nonnative aquatic species, and in particular fish, are, along with dewatering of habitat, the most significant threats to the roundtail chub in the lower Colorado River basin.
EXCERPT RE: CLIMATE CHANGE: If predicted effects of climate change result in persistent drought conditions in the Colorado River basin similar or worse than those seen in recent years, water resources will become increasingly taxed as supplies dwindle and demand stays the same or increases. Likewise, there would be increased demand on surface and groundwater supplies in Arizona. Clearly, permanent water is crucial for the continued survival of native fish in the region, including roundtail chub. Essentially the entire range of the roundtail chub in the lower Colorado River basin is predicted to be at risk of becoming more arid (Seager et al. 2007, pp. 1183–1184), which has severe implications to the integrity of aquatic and riparian ecosystems and the water that supports them. Perennial streams in the region may become intermittent and streams that are currently intermittent may become unsuitable or dry completely.