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tagged with a Carlin dangler tag attached through the dorsal musculature immediately below the posterior one-third of the dorsal fin. Sampling equipment The effectiveness of electroshocking equipment is diminished sub- stantially by high conductivities, great depths, and high turbidities encountered in the Green River. However, a Coffelt RF-10 unit was used since a rotating field with pulsed DC current is reasonably effective under these conditions. The unit employed a 4.0-kilowatt, 220-volt generator as a power source. A smaller unit of 1.8 kilowatt was also used on a raft in canyon areas. Conductivities fluctuated during the year, requiring frequent adjustments of the electrical equipment. Electroshocking gear was especially useful in collecting Colorado squaw- fish, a species which appeared to be more vulnerable to electroshock than others. Another unit (Coffelt WP-15) was employed as a replacement of the RF-10 unit in 1981 and proved more effective. Fishing effort was measured in hours. Trammel nets were set in slow-flowing runs and eddies. Nets were tended regularly, from 1- to 3-hour intervals depending upon temperature and conditions. Gill nets were occasionally used as supplemental gear but were generally discontinued. The trammel nets were 1-inch and 1.5-inch (2.5-centimeter to 3.8-centimeter) bar mesh, 150 feet long x 6 feet deep (45.0 meters x 1.8 meters) with a wall of 10-inch to 12-inch mesh (25.4-centimeter to 30.5-centimeter), respectively. Fishing effort was measured in net hours. Funnel-type wire traps of 1-inch (2.5-centimeter) chicken wire, approximately 1.5 feet (0.5 meters) in diameter x 2-1/2 feet (0.8 meters) long were set among large boulders or accumulations of debris. Compact, durable, time-efficient physical and chemical data. This 201 portable water velocity meter, velocity measurements were taken at Water depths were recorded with a col depth finder (Model LRG 1510A). equipment was procured to collect included the Marsh-McBirney Model a direct-readout device. Water 0.6 distance from the substrate. .lapsible stadia rod and a Lowrance Total dissolved solids, salinities, and conductivities were measured with a Yellow Springs Meter (Model 33) which had a combined conductivity and temperature probe. Conductivity was expressed as micromhos per centimeter. Salinity was temperature compensated and recorded in grams per kilogram. A Hach Colorimeter (Model DR/1) was used to measure dissolved oxygen and turbidity. Turbidities were measured in formazin turbidity units (FTU) which are equivalent to Jackson turbidity units. No single technique efficiently sampled all habitats for all sizes and species of fish. Every attempt was made to use gear or combinations of gear that would adequately sample a cross section of the fish popula- tion in each habitat. The gear most utilized were seines. While a variety of seine sizes and meshes were used, 1/4-inch mesh nets were used predominantly. 12