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Water Withdrawal and Agricultural Run-off Among the Threats to the Prairie Chub
Contact: Taylor Jones (303) 573-4898 x1159

Washington, DC—The U.S. Fish and Wildlife Service (Service)will announce in tomorrow’s Federal Register that the prairie chub (Macrhybopsis australis),a 3-inch fish that inhabits the Red River Basin of the Texas panhandle andOklahoma, may warrant protection under the Endangered Species Act (ESA). Thedecision comes in response to a petition by WildEarth Guardians, a western U.S.conservation group. The Service will conduct a full status review to determinewhether or not it will propose the fish for federal protection.

“The prairie chub may be small, but its decline is anindication of something much bigger; severe environmental degradation in theRed River Basin,” said Taylor Jones, Endangered Species Advocate for WildEarthGuardians. “We’re glad the prairie chub has made it one step closer to theendangered species list, because if the chub is protected, everything andeveryone in the Red River Basin will benefit from a cleaner, healthier riversystem.”

The prairie chub grows to about 3 inches in length, and is apale, translucent gray with small black spots on its sides. It is usually found in large shallow riversover gravel or clean sandy streambeds. This fish has a relativelyshort lifespan; few individuals survive to their third year. Adapted to the volatileconditions of prairie waterways, it can live through natural drought, flooding,and high salinity levels in its freshwater home. But lately it has beenfacing unprecedented challenges.

Its Red River Basin habitat, a network of rivers, streams,and watersheds criss-crossing the Texas panhandle and extending into Oklahoma,has changed drastically since the days when fire, bison grazing, and floodingwere the main shapers of the floodplain ecosystem. Today, fire is suppressed, bison are almost completely gone,and the natural flood regime of the rivers has been drastically altered by damsand irrigation withdrawals. The land throughout the Red River Basinis mainly used for agriculture. TheService recognizes that habitat loss due to impoundments such as dams anddikes, water withdrawal for irrigation, and pollution from agricultural run-offmay present significant threats to the prairie chub.

The streamsand rivers of the Red River Basin are studded with dams and smallimpoundments. A total of 660reservoirs and 3,877 impoundments have been constructed within the prairiechub’s known distribution. Twenty-eight percent of the streams within the prairie chub’s riverdrainage have at least 1 impoundment. Dams and reservoirs create barriers and eradicate fish fromstreams they once inhabited: as just one example, the Altus Dam on theRed River eliminated the prairie chub population above the dam.

Ground andsurface water withdrawals for irrigation could cause reduced water flows in theupper Red River Basin. Reducedflows would be bad for the prairie chub, as it is likely a broadcast spawner, releasingits eggs into moving water to travel downstream. Any alteration of the natural flow regime, from impoundmentsto reduced flows from irrigation, could negatively impact the chub’sreproductive success.

Pollutionfrom agricultural run-off also affects the chub. The Environmental Protection Agency considers 10 out of the14 streams known to support prairie chubs to be impaired by an array ofagricultural pollutants, including fecal coliform E. coli, chlorides,selenium, sulfates, lead, Toxaphene, and DDT.

“The chub is tough, but it’s not that tough,” said Jones. “Natural variations in prairie streams are one thing, but the chub mustface an onslaught of pollutants and the loss of many of its waterways. Without federal protection, it likelywon’t make it.”

In its full status review of the prairie chub, the Serviceintends to examine the effects of the replacement of native willows andcottonwoods with invasive saltcedar and Russian olive. TheService will also investigate possible effects of climate change, which mayalready be causing a rise in temperatures across the United States and mayincrease extreme weather events within the Great Plains including droughts,heavy rainfall, and heat waves.

Guardians petitioned the prairie chub (Macrhybopsisaustralis) as part of “Prairie Week” during its BioBlitzes in 2010. Otherspecies for which Guardians took action (either petitions or lawsuits) duringPrairie Week were: the Platte River caddisfly, Texas kangaroo rat, spot-tailedearless lizard, and the Scott’s riffle beetle. Altogether, the groupfiled petitions for 60 species in 2010, which was the International Year ofBiodiversity.

For background information, including the prairie chub listing petition and the FederalRegister finding, contact Taylor Jones at tjones@wildearthguardians.org or (303)353-1490.

See the Positive Petition Finding here.