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<br />11 <br /> <br />Data stratification <br /> <br />Fish sub-groups <br /> <br />& <br /> <br />Observations were classified by season, flow, species, life <br /> <br />~ <br /> <br />stage, and ,activity. Length-frequency tables compiled from this <br /> <br />study were used to determine the si ze cutoff between j uvenil e and <br /> <br />adult fish. <br /> <br />This cutoff changed slightly between seasons as a <br /> <br />result of growth. During the wi nter, fi sh ~25 em were cl assifi ed <br /> <br />as juveniles and larger fish were considered adults. During the <br /> <br />summer, 23 cm was used as the division between life stages. <br /> <br />Stationary and random swimming were the two primary activities <br /> <br />observed for the study species. The activity of stationary swim- <br /> <br />ming was defined as maintaining a stationary position by actively <br /> <br />swimming against a current. Swimming without orientation toward <br />a current (found only in low velocity water) that did not produce <br />a net change in location was defined as random swimmi ng. Fi sh <br /> <br />engaged in one of the above categories that were observed consum- <br /> <br />ing particles were designated as feeding during the respective <br />.... <br />activity. Resting activity (fish that remain stable with no <br /> <br />swimming motion, normally by lying on the river bottom) was not <br /> <br />observed for either of the two study species. <br /> <br />Collection schedule <br /> <br />Observations of fish were made primarily in the upper 7 km <br /> <br />of the study area. <br /> <br />All dives were made during midday periods <br /> <br />(0900-1700.ih). Data were never taken from the same location <br /> <br />twice for the same season and flow. An effort was made to sample <br /> <br />. <br /> <br />the same locations for the different seasons and especially for <br />