Difference between revisions of "GCDAMP RAZU Fish"

• High Country News: Canyon’s depths—but will the razorback sucker stick around?
• AZ Daily News: Razorback Sucker turns up in Grand Canyon after 20 years
  • The last one recorded had been caught in 1990.
  • Caught October 9th, lower part of Grand Canyon believed to have traveled upstream some 50 miles from Lake Mead.

Status and distribution

• Listed as endangered and given full protection under the Endangered Species Act in 1991.
• Endangered under Colorado law since 1979.
• Protected under Utah law since 1973
• Historically, the razorback sucker was widespread and abundant in the Colorado River and its tributaries.

Today all populations of razorback sucker are supplemented with stocked fish except for the Lake Mead population. Lakes Mead and Mohave are the only population with wild fish.

Working to recover the species

Actions being taken to recover the razorback sucker include:

• Managing water to provide adequate instream flows to create beneficial water flow
• Constructing fish passages and screens at major diversion dams to provide endangered fish with access to hundreds of miles of critical habitat
• Restoring floodplain habitat
• Monitoring fish population numbers
• Managing nonnative fishes

In addition, the Recovery Program works to reestablish naturally self-sustaining populations of razorback sucker through propagation and stocking. The Recovery Program maximizes the genetic diversity of wild broodstock used to produce fish in hatcheries to increase the likelihood that stocked fish can cope with local habitats.

In the Upper Colorado River Basin, razorback sucker are raised at two units of the Ouray National Fish Hatchery: the Grand Valley Unit in Grand Junction, Colorado, and the Ouray Unit in Vernal, Utah.

Razorback sucker raised at these facilities are stocked in the Colorado, Green, and Gunnison rivers. Efforts to reestablish populations through stocking demonstrate success as stocked fish survive to sexual maturity and reproduce. Fish stocked in the Colorado and Green rivers have been recaptured in reproductive condition and often in spawning groups. Captures of larvae in the Green and Gunnison rivers document reproduction and their survival through the first year is evidenced by subsequent captures of juveniles.

Stocked fish are moving between the Green, Colorado, and Gunnison rivers. This exchange of individuals between rivers suggests that razorback sucker may eventually form a network of populations or subpopulations.

Recovery goals

Razorback sucker will be considered eligible for downlisting from “endangered” to “threatened” and for removal from Endangered Species Act protection (delisting) when all of the following conditions are met:

• Self-sustaining fish populations reach the required numbers in areas of the Green River subbasin and EITHER the Colorado River subbasin or San Juan Rivers, and the Lower Colorado River Basin, and a genetic refuge is maintained in Lake Mojave as identified in the chart below.
• The threat of significant “fragmentation” of the population has been removed. (Fragmentation refers to separation between fish populations caused by geographical distance or physical barriers.)
• Essential habitats, including primary migration routes and required stream flows are legally protected.
• Other identifiable threats that could significantly affect the population are removed.

2015

• Razorback Sucker in Lower Grand Canyon and the Lake Mead Inflow Area--A History of the Species and Biological Opinions
• Razorback Sucker Monitoring and Research in Lower Grand Canyon and the Colorado River Inflow Area of Lake Mead
• Razorback Sucker Xyrauchen texanus Research and Monitoring in the Colorado River Inflow Area of Lake Mead and the Lower Grand Canyon, Arizona and Nevada

2014

• New Information on Razorback Sucker in Western Grand Canyon and Lake Powell
• New Information on Razorback Sucker in Western Grand Canyon
• Native Fish Population Trends – Grand Canyon Tributaries Razorback Sucker: Status and Habitat Use (Healy)

Ongoing actions:

Reclamation would continue to assist the NPS, FWS, and the GCDAMP in funding larval and small-bodied fish monitoring in order to:

• Determine the extent of hybridization in flannelmouth and razorback sucker collected in the western Grand Canyon.

• Determine habitat use and distribution of different life stages of razorback sucker to assist in future management of flows that may help conserve the species. Sensitive habitats to flow fluctuations could be identified and prioritized for monitoring.

• Assess the effects of TMFs and other dam operations on razorback sucker.

Quick Facts

Razorback Sucker- EP

• HISTORY

• POTENTIAL THREATS: