9716

• UCREFRP Catalog Number: 9716
• Author: Stone, D., and P. Sponholtz.
• Title: Translocation of young-of-year humpback chub above Chute Falls in the Little Colorado River, AZ, 2003 Interim Report.
• USFW Year: 2003.
• USFW - Doc Type: U.S. Fish and Wildlife Service
• Copyright Material: NO

RESULTS
Water Chemistry
During the July 2003 reconnaissance trip the daily mean water turbidity measurements
ranged from 0.60 to 0.94 NTUs and water temperatures, during C02 measurements, from
21 to 24° C (Table 1). Mean C02 levels were 193 mg/L at 13.87 RKM (below Upper
Atomizer Falls); 200.7 mg/L at 14.0 RKM (most upstream point where humpback chub
were historically captured); 205.3 mg/L at 14.2 RKM (just above Chute Falls); 208.6 mg/L
at 14.71 RKM; 216.7 mg/L at 15.32 RKM; 216.0 mg/L at 16.75 RKM; 288.6 mg/L at 19.55
RKM (highest point where speckled dace were observed during this study); and 566.4 mg/L
at 20.72 RKM (Blue Springs). Generally, these C02 levels at specific RKMs closely
mirrored historical patterns described by Mattes (1993) for July 1993 and Robinson et al.
(1996) for June 1994 (Figure 2). All three studies were conducted during baseflow
discharge and contained analogous water temperatures (21-24°C ) and turbidity
measurements (0.60 to 3.1 NTUs) above Chute Falls. The C02 levels from all three
studies were consistently highest at Blue Springs, dropped expeditiously within the first
kilometer, and gradually declined thereafter.
Table 1. Water quality values (mean, ±1 standard error) from the Little Colorado River
taken during three trips in 2003 (reconnaissance, translocation and monitoring) by AZFRO.
NT indicates no sample taken.
Trip Temperature Turbidity DO pH Conductivity
(°C) (NTIJ) (mg/L) (µS)
Reconnaissance (July 7-11, 2003) 21.7±0.7 0.81±0.1 NT NT NT
Translocation (July 28-Aug 1, 2003
Capture site (1.9 RKM) 25.2±0.4 NT 7.4±0.2 7.8±0.06 4529.0±39.5
Release site (16.2 RKM) 22.7±0.01 NT 9.8±0.02 7.2±0.01 4634.0±8.0
Monitoring (Oct 31-Nov 3, 2003) 19.7±0.3 4.9±0.7 12.7±0.3 7.3±0.01 4608.5±3.7
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