7103

• UCREFRP Catalog Number: 7103
• Author: Grabowski, S. J. and S. D. Hiebert.
• Title: Green River Trophic Dynamics Study 1987
• USFW Year: 1988.
• USFW - Doc Type: Draft.
• Copyright Material: NO

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(BA-249.7) was similar in size, shape and orientation as Squaw Creek
backwater.

Limnological sampling

At each study location (Island Park, Jensen, and Ouray) one main river
site and several backwaters were sampled. The physical-chemical profile
was collected using a Hydrolab Corp. Surveyor II multiparameter probe
which measured water temperature (OC), dissolved oxygen (mg/L), pH,
specific conductance (~S/cm), and oxidation-reduction potential, used
to calculate E7. In the main river, the calibrated probe was held
about 0.3 m below the water surface, in flowing water, and parameters
were recorded after instrument equilibration. In the variously-sized
backwaters, the probe was held between 0.1 and 0.3 m below the water
surface, and parameters recorded after instrument equilibration.

Water samples for analysis of major ions (Na, K, Ca, Mg, HC03, C03,
Cl, and S04), nutrients (total P, ortho-P, N02, NH3, and TKN), and
heavy metals (Cd, Cu, Fe, Pb, Mn, Zn) were collected in the main river
and selected backwaters. Initially, a one-liter water sample was collected
for major ions and kept cold, a 500-mL water sample was collected for
nutrients and placed on dry ice, and a 250-mL water sample was collected
for heavy metals and preserved with 2.0 mL of concentrated HN03' Later
in the study, collection of water samples for major ion and heavy metal
analysis was discontinued on a biweekly basis but continued on a seasonal

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