WASHINGTON (CN) - Two fish in the minnow family found only in the southwest's desert headwaters were proposed for threatened species status under the Endangered Species Act Wednesday.
The U.S. Fish and Wildlife Service hs proposed protecting the headwater chub and a distinct population segment of the roundtail chub. Both chubs are found in the Lower Colorado River Basin in Arizona and New Mexico, and the two species' habitats overlap in some areas.
The two chubs were placed on the candidate species list in 1982, but the headwater chub was not listed due to lack of information. A distinct population segment of the roundtail chub was found to merit listing, but was precluded by higher listing priorities.
Wednesday's action was prompted by the 2011 settlement agreement between the agency and the Center for Biological Diversity (CBD) and its allies, that mandates listing determinations for hundreds of species within a 6-year period.
"Our long abuse of the southwest's desert rivers has taken a toll on the many plants and animals that depend on these oases, and these two fish are no exception," Noah Greenwald, endangered species director at the CBD said in the group's response to the proposal. "I'm hopeful that Endangered Species Act protection for two more fish species will spur action to restore rivers that are the lifeblood of the region for people and other animals alike."
The headwater chub can grow up to 12 inches long and the roundtail chub is a bit larger at 14 inches. Both fish are similar in appearance and have a lifespan of about 8 years.
The roundtail chub occurs in two distinct populations, one in the upper Colorado River Basin and one in the lower Colorado Basin. It is the lower basin population that is being proposed for listing.
The fish are threatened by non-native fish, habitat destruction due to dams, channelization and groundwater pumping, as well as mining, grazing, pollution, development and climate change, according to the agency.
"Water is obviously a scarce resource in the desert southwest, and virtually all climate models predict hotter and drier times ahead," Steve Spangle, Field Supervisor for the Service's Ecological Services Office in Arizona, said. "When you add these stressors and non-native predators to the equation, the outlook isn't good for many native fish. But it's our hope we can work closely with partner agencies such as the Arizona Game and Fish Department to prevent further declines and eventually recover these species."
The USFWS is also proposing a special rule under Section 4(d) of the ESA to provide exemptions from some prohibitions of the act. Such exemptions are only allowed for listed species that have a threatened status. The exemptions would cover roundtail chub that live in agricultural and urban canals or fishable waters, and would exempt operational and maintenance activities on state, private and tribal lands and waterways, such as canals and stock tanks, from the requirement to obtain a permit in cases where an otherwise lawful activity incidentally harasses, harms or kills the fish, according to the agency.
The agency finds that a critical habitat designation is "not determinable at this time," according to the action.
"North American freshwater species are going extinct at a rate comparable to the loss of species from tropical rainforests and 1,000 times faster than the background rate in the fossil record," said CBD's Greenwald. "We're at risk of losing nearly the entire aquatic fauna of the Southwest, which is a tragedy that can't be undone."
Comments on the listing proposal are due by Dec. 7, and written requests for a public hearing are due by Nov. 23.
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