9545 - Laserfiche WebLink

Home Browse Search

Table 1. Description of flow and temperature parameters correlated with YOY chub growth and CPE as collected in Westwater Canyon of the Colorado River; 1992 -1996. FLOW PARAMETERS DESCRIPTION STPK Instantaneous spring peak flow recorded on the Colorado River at the Stateline, Utah, gage STPKPRE Instantaneous spring peak flow recorded on the Colorado River at the Stateline, Utah, gage the year prior to sampling CISPK Instantaneous spring peak flow recorded on the Colorado River at the Cisco, Utah, gage PRPKFLO Cumulative flow-days (a la degree days) in excess of 6000 CFS prior to June 1 POSPKFLO Cumulative flow-days (a la degree days) in excess of 6000 CFS after June 1 PREPKIO Degree -days >10 C; prior to June 1 POSPK20 Degree -days >20 C; after June 1 CISMAYDEV Deviation of the May monthly mean flow from the pre-Aspinall (1914-1962) May monthly mean (50 %exceedence) [absolute value] CISJUNDEV Deviation of the June montlily mean flow from the pre-Aspinall (1914-1962) May monthly mean (50 %exceedence) [absolute value] Fish Community Fish community monitoring was conducted at three locations established for the ISMP. Those sites were: Miner's Cabin (RK 199.9 - 198.6), Cougar Bar (RK 194.4 - 193.8), and Hades Bar (RK 192.2 - 191.8). Each site is bounded upstream and downstream by a riffle area. Depth measurements collected in May 1994 revealed the following maximum site depths: Miner's Cabin - 21.8 m, Cougar Bar - 19.5 m and Hades Bar - 10.6m. On these trips, fish were sampled in main channel habitats with trammel nets (23 m x 2 m; 2.5 and 1.25 cm mesh), shorelines were sampled with sport boat mounted pulsed DC electrofishing and lm hoop nets. Sampling was conducted primarily during the crepuscular and night time hours. Trammel nets were checked every two hours, hoop nets were fished through the night. After capture, Gila spp. were transferred to holding pens, held through the sampling night, processed the following morning, and then released. Standardized catch rates are presented as fish /23m net hour for trammel net catch, and fish /hour electrofishing. The following information was collected from all chubs captured: total and standard length (mm), weight (g), dorsal and anal fin ray counts. In 1991, while conducting the Gila taxonomy trips, the UDWR received training in sexing Gila spp. from Dr. M. Douglas (Arizona State University). Chubs larger than 200 mm TL were sexed by examining the urogenital opening. Body scales were collected each trip from a representative sub-sample of the catch. Chubs in excess of 175 mm TL were PIT tagged. Recaptured fish provided data for analyses of movement and growth. For the present study, movement was described as capture at a location other than the site of previous capture. Distances between sites were 4.2 km from Miner's Cabin to Cougar j Bar, 2.4 km from Cougar Bar to Hades Bar, i.e., 6.6 km overall. Recapture data was also used to I 4