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I I I I I I I I I I I I I I I I I I I State biologists in Nevada are collecting and rearing razorback suckers that were naturally spawned in Lake Mead (Jim Hendrick, NDOW personal communique). It appears that similar efforts to capture larvae will not only be attempted, but expanded in future years. It,s speculated these fish will probably be used to augment Lake Mead's population. Stocking of adult suckers would seem to be a logical step to maintain or expand existing populations. While some biologists feel any stocking attempt would simply result in fish being flushed downstream, we simply won't know until someone tries. Even if fish were simply flushed down into Lake Mead, some feel that additional razorback suckers in that reservoir would be a positive direction for the fish. This avenue could be explored with Grand Canyon National Park and the States of Arizona and Nevada and ifit's positive, suckers raised in these ponds could be use. Iceberg Canyon There has been some discussion about the use of the perched lake at Iceberg Canyon. This site was surveyed and mapped in 1995. The lake was formed when part of the canyon wall collapsed and formed a natural dam. The canyon is spring fed and at the time of the survey, the lake's elevation was about 10 meters higher than the reservoir's. During the past two years, high Lake Powell elevations have resulted in the reconnection of this area to the reservoir. The last reconnection resulted in a large fish kill. It's believed that inundated vegetative material caused a massive oxygen demand that depleted dissolved oxygen concentration resulting in fish affixation. This would probably only occur following full reservoir conditions. Virtually nothing is known regarding the predatory interactions or spawning requirements of native fish. Natural reproduction has occurred for both razorback suckers and bonytail chub that have been stocked in small, isolated ponds adjacent to Lake Mohave (Tom Burke personal communique). It's apparent recruitment is possible under some conditions. The lake found at the terminal end of Iceberg Canyon has the potential of not only growing larger fish but possibly providing the conditions required for natural recruitment. When reservoir elevations retreat, existing non-native fish would be removed and restocked with a native fish community. The resulting efforts could be the focus of research into the behavior and interactions of such species as razorback and bonytail. Populations could be maintained and controlled by stocking or the removal of large adults destined for other appropriate locations. If the reservoir does rise and overtop the existing berm, the fish would simply escape into the reservOIr. RECOMMENDATIONS We recommend the experiment be phased into an actual program which is optimized to rear large razorback suckers or other endangered fish and foster public awareness and education concerning the plight of these fish. We recommend the following actions be considered and discussed among the appropriate parties: 8