A coalition of seven environmental groups, including the Center for Biological Diversity (AZ), Biodiversity Associates of Laramie, and Biodiversity Legal Foundation (CO) filed a formal petition today with the U.S. Fish and Wildlife Service (USFWS) seeking listing and protection for the Colorado River cutthroat trout. The agency has one year to decide whether it will list the native trout as threatened or endangered. Listing of the trout will result in much needed habitat protection and bolster state recovery efforts with an infusion of Federal funding and staffing.

One of the most spectacular of the colorful cutthroat trout, the Colorado River cutthroat has a crimson belly and distinct black spots covering the tail, sides and back. Historically found in all cold-water streams of the Colorado River drainage, including portions of Wyoming Colorado, Utah, and extreme northern New Mexico and Arizona, the Colorado River cutthroat trout has been reduced to less than five percent of its historic range and is now limited to small, isolated headwater streams, placing it in immediate danger of extinction. See enclosed map.

This severe range reduction was primarily caused by habitat loss to livestock grazing, logging, mining and water diversion, and the introduction and spread of nonnative trout, such as brook, rainbow and brown, which compete and hybridize with the native. These activities continue to limit recovery and harm remaining populations. "Like nearly all native trout in the west, the Colorado River cutthroat trout has been decimated by the thoughtless destruction of streams and stocking of nonnative species," according to Noah Greenwald, Ecologist for the Center for Biological Diversity. Jeff Kessler of Biodiversity Associates adds that "The Colorado River cutthroat trout is as much a part of the west as the elk and Grizzly Bear; if we lose the Trout we lose an irreplaceable part of the west's natural heritage."

The Groups' petition (a copy of the executive summary is attached) provides a detailed analysis of the status of and threats to every known population of Colorado River cutthroat trout and shows that the vast majority are threatened by one or more of the factors mentioned above. For example, at least one third of remaining pure populations occur in streams where livestock grazing is reported to be negatively impacting habitat, and another third have overlapping ranges with nonnative trout. Because of the extent of ongoing threats, the Groups are pursuing Federal protection for the Colorado River cutthroat trout, despite a recent voluntary Conservation Agreement signed by the three states. "Because most habitat and populations occur on Federal lands, protection for the Colorado River cutthroat trout at the Federal level is absolutely required," according to Kessler, adding that the Conservation Agreement is "too little, too late and fails to require protective action to ensure full recovery of the Trout."

Similar petitions have been filed for the Yellowstone, Bonneville, Rio Grande, and westslope cutthroat trouts. The Greenback, Paiute, and Lohantan are already listed by the USFWS as threatened, and two others, the Yellowfin and Alvord cutthroat trout, are extinct. "Loss of native trout from large portions of the west directly resulted from the systematic destruction and degradation of aquatic ecosystems from Mexico to Canada," states Jasper Carlton, Director of the Biodiversity Legal Foundation.

The most spectacular of the colorful cutthroat trout and one of the most beautiful fish in North America, the Colorado River cutthroat trout (Oncorhynchus clarki pleuriticus) is the only indigenous trout of the upper Colorado River system. Formally found west of the Continental Divide, in Colorado, southern Wyoming, eastern Utah, and extreme northwestern New Mexico and northeastern Arizona, the Colorado River cutthroat trout occupies less than two percent of its historic range, primarily in isolated, small headwater streams. This severe range reduction was primarily caused by the stocking and spread of non-native trout, livestock grazing, water diversion, logging, roads and mining. As a result of these factors, the Colorado River cutthroat trout now meets all five factors under the Endangered Species Act for consideration as a threatened species:

1. the present or threatened destruction, modification, or curtailment of its habitat or range. The Colorado River cutthroat trout has been reduced to small, unstable headwater drainages in less than 2% of its historic range. The factors that resulted in this catastrophic loss persist and threaten most remaining populations:
   • Livestock grazing is occurring in and adjacent to streams harboring 66% of remaining pure populations and is known to be negatively affecting the habitat of 33% of these populations.
   • Water diversions are impacting 21% of remaining pure populations, including limiting recovery in the North Fork of the Little Snake River, which harbors one of the last metapopulations and several conservation populations.
   • Mining is impacting the habitat of at least ten populations and is likely limiting recovery elsewhere.
   • In combination, logging and roads has negatively affected the habitat of 13% of remaining populations

2. Overutilization for commercial, recreational, scientific, or educational purposes. Colorado River cutthroat trout are easily caught by anglers, making them particularly sensitive to recreational fishery impacts. Though existing fishing regulations are in most cases adequate, recreational fishing still poses a potential threat for a couple of reasons. First, for the regulations to be effective, they must be followed and enforced. Given declining budgets for state game agencies, there is no guarantee that there will be adequate personnel to educate the public about the regulations and to enforce them. Second, to date, complete and systematic surveys for Colorado River cutthroat trout have not occurred in all waters of the three states. This leaves open the possibility that undiscovered waters containing remnant populations, which are not protected by the existing fishing regulations, will be over-fished.

3. Disease or predation. The Colorado River cutthroat trout and other western native trout species are threatened by whirling disease, an introduced and fatal parasite. Significantly, the Colorado Division of Wildlife has stocked hatchery fish with whirling disease into streams within the historic range of the Colorado River cutthroat trout and as a result one population of the native has already been infected.

   Predation is also a threat to the continued existence of the Colorado River cutthroat trout because introduced trout, such as brown, brook and rainbow, prey on young cutthroat. This predation is a factor in the common displacement of Colorado River cutthroat trout by non-native trout.

4. The inadequacy of existing regulatory mechanisms. There are currently no regulations that protect the Colorado River cutthroat trout from take or habitat degradation, which as noted above is ongoing. The three states with populations of Colorado River cutthroat trout have been taking voluntary action to restore populations of Colorado River cutthroat trout, including developing a conservation strategy. These actions usually involve finding streams with limited resource conflicts, and then removing non-natives and transplanting or stocking hatchery raised Colorado River cutthroat trout into them. To date, these actions have not resulted in substantial recovery of the species, primarily because state conservation actions are contradicted by the past and present stocking of non-native trout within the historic range of the Colorado River cutthroat trout by the same state agencies, and because most habitat and populations occur on Federal lands, where the state's have little power to affect necessary changes in management to remove resource conflicts. In addition, limited funding, human resources, and the voluntary nature of the current and past conservation strategies has resulted in inconsistent implementation. Thus, the Colorado River cutthroat trout remains unprotected by substantive regulation.

5. other natural or manmade factors affecting its continued existence . The introduction and subsequent spread of non-native trout presents one of the single greatest threat to the continued existence of the Colorado River cutthroat trout. Brook and brown trout both out-compete and prey on native cutthroat, usually leading to complete displacement; and rainbow trout readily hybridize with the native leading to effective extinction of native stocks. Currently, 34% of remaining pure populations have sympatric ranges with non-native trout and an additional 29% are not protected by a barrier.

   In large part because of non-native trout, but also habitat degradation, the Colorado river cutthroat trout is now found in exceedingly small and isolated streams. As a result, most populations consist of far less than 200 reproducing individuals, which is below minimum numbers to preserve population genetic integrity and population viability. This problem is furthered by the isolation of populations, precluding genetic interchange among populations. Populations in small streams are also highly subject to extirpation caused by stochastic disturbances, such as drought, fire or flood. Once populations are lost to these factors, there is little chance habitat will be recolonized because of the isolation of most current populations.

In sum, there are very few remaining populations that are native and secure from all of the above threats. Only 39 populations of Colorado River cutthroat trout in 122 miles of stream, for example, are indigenous, genetically pure and secure from non-native trout and only two of these are also secure from livestock grazing, logging, water diversion, roads, mining or habitat limitations. Considering all pure populations, whether they are indigenous or not, there are only 15 that are secure from non-natives and other threats. Thus, the Colorado River cutthroat trout is in critical need of protection under the Endangered Species Act.