A Sucker for Attention

Photo Credit:  Abraham Karam (Courtesy High Country News) 

Meet the razorback sucker (Xyrauchen Texanus):  a fish endemic to the Colorado River Basin.  This fish, which can grow to three feet in length and live for almost half a century, may have been navigating the Colorado's waters as far back as five million years ago, according to the Upper Colorado Native Fish Recovery Program.  However, over the last century and a half, a suite of native fishes has been introduced to its habitat and its population has begun a precipitous decline ever since.  Non-native fishes such as carp eat the razorback sucker eggs, while sunfish each both the razorback sucker eggs and young, according to the Rescuing the Razorback Sucker page of the USGS's website (Fort Collins Science Center section).  As of October 23, 1991, the species has been listed as "endangered" throughout its entire range.

Courtesy Grand Canyon River Outfitters Association

In recent weeks, however, this often forgotten fish has shown up on the popular media's radar.  On October 9th, a fish-surveying group that was electrofishing in the lower part of the Grand Canyon came across a single razorback sucker.  This was a particularly exciting find, considering that the National Park Service's website claims that the razorback sucker "may be extirpated" (locally extinct) the Grand Canyon.  According to the LA Times, some researchers "believe the fish might have traveled some 50 miles upstream from Lake Mead."


Basically, while the species was "historically widely distributed throughout both the Upper and Lower Colorado River," no razorbacks had been found in the Grand Canyon in recent years.  In fact, the last fish on record in the Grand Canyon area was caught in 1990, according to the Arizona Daily Sun.

Razorback Stocking. Courtesy USFWS

Rescuing the Razorback Sucker explains that the razorback sucker population experienced a 60% decline in just four years:  from 59,500 in 1988 to 23,300 in 1992.  This had led to conservation efforts by various teams of researchers working on Lake Mohave, where the largest and most genetically diverse population of razorback suckers remains.  These efforts include capturing razorback larvae, rearing them in safe locations, and stocking them back into the river as adults with better survival chances.


In addition, the Upper Colorado Native Fish Recovery Program lists the following efforts being taken to recover the razorback sucker in other locations on the Colorado River:

• 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

Unfortunately, it's not only the razorback that's in trouble.  The Arizona Daily Sun article discussing the recent razorback capture also mentions how the Grand Canyon Wildlands Council found that "seven kinds of plants, nine types of insects, eight breeds of fish, 19 birds and 31 mammals...about 85 species, at least" are currently at risk just in the Grand Canyon, a quarter of which may already be extinct.  Fish species such as the Colorado pikeminnow, the humpback chub, and the bonytail face "impacts from dam building, diversions and channelization" that could push "the fish toward the brink of extinction," according to an article posted on the Summit County Citizen's Voice Blog on October 23, 2012.  The article goes on to discuss some of the important collaborative efforts taking place in the Upper Colorado River Basin--such as maintaining flows, removing non-native species, and operating fish screens, as well as taking advantage of low-flow conditions to repair infrastructure--that are helping to sustain fish populations.

Biologist Dave Speas with a bonytail.

Courtesy Summit County Citizen's Voice Blog

The large number of species at risk, coupled with the surprising sighting of a razorback sucker in its former habitat, serves as an important reminder of the need to consider various perspectives when managing the Colorado River system, especially in times of drought.  When coupled with some of the economic and social issues mentioned in my previous post, as well as the fact that millions of people now depend on the Colorado River for domestic and agricultural water supply, it's impossible to predict how much attention will be given to essential conservation recommendations like those listed above.