Yakima Benthic Index of Biotic Integrity : Progress Report 2001-2002.

Sample collections in project-years two and three (2001 & 2002) proceeded as planned. Twenty-eight (28) sites were sampled in 2001 between August 14 and September 12. Sites included two (2) mainstem Yakima River sites between Selah Gap and Union Gap, three (3) Yakima river sites upstream of Roza Dam, and three (3) mainstem Naches River sites between Cliffdell and the Wapatox Canal. The other twenty sites were tributary sites, including the Cle Elum River below Cle Elum Lake, lower Bumping river, and the American River at Pleasant Valley. Six (6) tributaries of second to fourth order were sampled at or near the same location at which they were sampled in 2000, as were two sites on the upper mainstem Yakima and one on the mainstem Naches. Thirty-three (33) sites were sampled in 2002 between August 12 and September 13. These included one (1) mainstem Yakima River site between Selah Gap and Union Gap, four (4) sites in the mainstem Yakima upstream of Roza Dam, and two (2) sites on the mainstem Naches between Naches and Cliffdell. The other twenty-six (26) sites were tributary sites, including one (1) site on the lower Tieton river, three (3) sites on the Bumping Rivermore » (two downstream of Bumping Reservoir and one upstream), and two sites on the American River. Four (4) other sites were on smaller tributaries to the mainstem Naches, three (3) of which had been sampled in one (1) of the two preceding years, and one (1) (upper Rattlesnake Creek) that has been sampled in all three (3) years. Two (2) tributary sites in the upper Ahtanum subbasin were sampled, one (1) of which was sampled in 2000 and the other of which has been sampled in all three (3) years. One tributary (lower Wenas Creek) to the mainstem Yakima upstream of Selah Gap and downstream of Roza Dam was sampled. This was also sampled in 2001. Thirteen (13) sites were sampled in tributaries to the upper Yakima River, including two in the Teanaway subbasin one of which was sampled in 2000 and the other of which was sampled in 2001. Over the three (3) years of sample collection under the project to date, a total of 93 site-years have been sampled from 59 distinct sites. Of these 31 have been sampled once, 22 have been sampled twice, and 6 have been sampled three times. Of the 93 site-years, 23 are mainstem Yakima and Naches River sites, 31 are mainstem and tributary sites within the Naches River subbasin, and 46 are mainstem and tributary sites within the Yakima River subbasin upstream of Roza Dam. The majority of tributary and mainstem sites occur between elevations of 1400 and 2900 feet above mean sea level. Eight (8) distinct sites (ten (10) site-years) occur at elevations above 3000 feet. Two (South Fork of Manastash Creek at Buck Meadows and North Fork of Ahtanum Creek) occur at elevations above 4000 feet.« less