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channel. In areas with more than one channel the replicates were divided between channels in <br />the same proportion that the channels make up the habitat. If a channel was less than 25 ft wide <br />a width measurement was taken and the total area sampled was adjusted accordingly in the final <br />calculations. Ideally each seine haul sampled 0.0287 acres. However if the random point fell in <br />a channel less than 25 wide the area sampled for that replication was reduced proportionally and <br />the total area sampled would be reduced for the purposes of density estimates. <br />The amount of each habitat sampled is measured and allows for the calculation of fish densities <br />per acre. Thus number is either than multiplied by the acres of that habitat type within a study <br />site to get fish per habitat type per site. All habitat types are then combined to get a total number <br />of fish which is an estimate of abundance. This abundance estimate can then be expanded to <br />make an estimate of abundance over larger reaches of the river. <br />Backwaters, side channels, snags and banks were sampled by backpack electrofishing. Sampling <br />of banks consisted of electrofishing SO linear feet (15 meters). From 1999 to 2005 five replicate <br />samples were randomly chosen from all habitats other than open channel. In 2007, a total of 3 <br />snags were sampled if available and backwaters were sampled 15 m either side of a transect <br />when one of the six transects transversed a backwater. Side channels were sample for 25 m <br />either side of the anchor transect. Banks of open and side channels were sampled along 15 m of <br />bank where the anchor transect bisected the bank (WEST 2007). In addition in 2007 at least 30 <br />m of bank that contained some sort of cover (i.e. vegetation or rip-rap) was sampled when <br />available even if it was not bisected by the anchor transect. <br />In previous reports we have analyzed data in two ways one included young of year (YOY) fish <br />and one did not. In 2005 it was noted that many of the YOY were able to go through the mesh of <br />the seines and dip nets. Therefore from here on out YOY of year fish will only be included if <br />they can be identified to species. All analysis relative to past years does not include YOY. This <br />eliminates some of the significant differences noted in the 2003 report. <br />All statistical analysis was run using Statistix 8.0 for Windows or Microsoft Excel. <br />Results <br />Fish sampling was completed at Elm Creek, Overton and the Cottonwood Ranch Property sites <br />on August13, 2007. The average daily flow at the Overton gauge (Station Number 06768000) <br />on August 13, 2007 was 538 cfs and was declining from flows of over 2,000 cfs in late July. The <br />Lexington and Alda sites were sampled on August 14, 2007 at which time the average daily flow <br />at the Grand Island Gauge was 1,180 cfs and declining from a flow of over 2,000 cfs in late July. <br />The Grand Island Gauge showed zero flow August 5- 30, 2002, July 25 - November 16, 2003, <br />June 12-17, 2004, August 3 to October 8, 2004, August 4-11, 2005 and July 17- August 8, 2007. <br />In 2007 open channel accounted for 78% of the fish caught. Based on available habitat <br />calculations open water accounts for 96% of all fish estimated to be with in the study sights. The <br />distribution of fish within the open channel habitat is patchy as demonstrated by the variability of <br />fish caught per seine at each site (Appendix B). While open water accounts for the vast majority <br />of fish backwaters had the highest fish densities (3677 fish per acre) but were limited in their <br />distribution Table 1.