Starvation eyes.

[PREDATOR]

[size 1]We enlisted Utah State University to conduct research on Starvation, Yuba and Deer Creek in 1996 and have had an ongoing program for Starvation and Yuba until this year. [/size][size 1]Relative to Starvation's population dynamics, the research has demonstrated that it is very poor in forage and that the walleye population far exceeds its food supply. The chubs that provided the forage base could not produce enough young each year to meet the needs of the walleye population. As a result it appears that there has not been any recruits to the adult population in over 20 years. This concerned us as the population is expected to die off soon leaving no forage base whatsoever. So in 2000 we initiated a gill-netting program to remove as many walleye less than 14 inches in length as we could in an intensive 4-week program. That program has resulted in the removal of about 16,343 walleyes during the past three years. However, the results have not been encouraging. While the walleyes have shown better body condition and probably better growth the young chubs are still not making it to adulthood and are being totally consumed by the end of August.[/size] [size 1]Also, a new element has been added. Yellow perch have become established in the reservoir and changes the situation significantly. They were first seen in 2000 and the netting this past summer showed that they have increased substantially with over 1,000 being caught in this year's netting program.[/size] [size 1][/size][size 1]Since there is little likelihood that any chubs will survive in the face of this added predator, the effort to reduce the predatory pressure by removing walleyes is being abandoned.[/size] [size 1]The good side to all this is that for a time the forage situation will probably improve substantially for the short term and we should see good growth and condition of the walleyes. However, this is likely to become a very cycling situation with walleye numbers expanding to over exploit the yellow perch population and slowly decline until their numbers have declined enough to allow a resurgence in the yellow perch population and then the cycle of boom and bust will repeat itself. We may be able to manipulate this cycle in a modest way by encouraging anglers to catch and keep good numbers of walleyes during the boom years and possibly shorten the bust period with a timely netting and removal program.[/size] [size 1]For the time being I think we'll see some good walleye fishing that can be extended if we can convince anglers to take their legal limits of walleyes and have a liberal limit.[/size] [size 1]You may be wondering why we did not introduce the yellow perch or some other forage. We are inhibited from introducing exotic fishes into the Colorado River basin because of potential threats to the four native Colorado River fishes which are listed as endangered and for which an extensive recovery program is underway. Federal law prohibits any agency from taking any action which would threaten their survival and new species could add to the many already established non native fishes that have been a major factor in their demise already.[/size]