Prairie Fish Swims Upstream Towards Federal Protection

Water Withdrawal and Agricultural Run-off Among the Threats to the Prairie Chub

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 and Oklahoma, may warrant protection under the Endangered Species Act (ESA). The decision comes in response to a petition by WildEarth Guardians, a western U.S. conservation group. The Service will conduct a full status review to determine whether or not it will propose the fish for federal protection.

“The prairie chub may be small, but its decline is an indication of something much bigger; severe environmental degradation in the Red River Basin,” said Taylor Jones, Endangered Species Advocate for WildEarth Guardians. “We’re glad the prairie chub has made it one step closer to the endangered species list, because if the chub is protected, everything and everyone in the Red River Basin will benefit from a cleaner, healthier river system.”

The prairie chub grows to about 3 inches in length, and is a pale, translucent gray with small black spots on its sides.  It is usually found in large shallow rivers over gravel or clean sandy streambeds.  This fish has a relatively short lifespan; few individuals survive to their third year.  Adapted to the volatile conditions of prairie waterways, it can live through natural drought, flooding, and high salinity levels in its freshwater home.  But lately it has been facing 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 flooding were 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 dams and irrigation withdrawals.  The land throughout the Red River Basin is mainly used for agriculture.  The Service recognizes that habitat loss due to impoundments such as dams and dikes, water withdrawal for irrigation, and pollution from agricultural run-off may present significant threats to the prairie chub.

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

Ground and surface water withdrawals for irrigation could cause reduced water flows in the upper Red River Basin.  Reduced flows would be bad for the prairie chub, as it is likely a broadcast spawner, releasing its eggs into moving water to travel downstream.  Any alteration of the natural flow regime, from impoundments to reduced flows from irrigation, could negatively impact the chub’s reproductive success.

Pollution from agricultural run-off also affects the chub.  The Environmental Protection Agency considers 10 out of the 14 streams known to support prairie chubs to be impaired by an array of agricultural 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 must face an onslaught of pollutants and the loss of many of its waterways.  Without federal protection, it likely won’t make it.”

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

Guardians petitioned the prairie chub (Macrhybopsis australis) as part of “Prairie Week” during its BioBlitzes in 2010.  Other species for which Guardians took action (either petitions or lawsuits) during Prairie Week were: the Platte River caddisfly, Texas kangaroo rat, spot-tailed earless lizard, and the Scott’s riffle beetle.  Altogether, the group filed petitions for 60 species in 2010, which was the International Year of Biodiversity.

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

See the Positive Petition Finding here.

 


 

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