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<br />. <br /> <br />c::) <br />C") <br />.... <br />(0 <br />Cf) <br />o...J <br /> <br />. <br /> <br />. <br /> <br /> <br />Reach 3. In Reach 4, there was no pattern. In Reaches 5 and 4, channel catfish <br />abundance was usually slightly greater in secondary channels than primary; in Reach 3 in <br />1995 and 1996 secondary channel abundance was considerably greater. One adult <br />Colorado pikeminnow was collected in a secondary channel in 1994. Razorback suckers <br />(likely stocked individuals) were found in secondary channels in 1995, 1996, and 1997. <br /> <br />Fish species common during spring inventories were usually uncommon or rare in <br />summer collections; most individuals of these species found in summer were young-of- <br />year or juveniles. During summer, abundance of fishes in secondary channels varied <br />considerably from year to year (1991 through 1997). Greatest abundance (Reaches <br />combined) occurred in 1993 and 1995 and least in 1997. Shannon-Wiener Diversity was <br />slightly less in 1997 than 1993. In Reach 5, red shiner was the most abundant species in <br />four years, fathead minnow in two, and bluehead sucker in one. Bluehead sucker (almost <br />all Age 0) summer abundance was greatest in 1995, a high spring runoff year. Speckled <br />dace was usually second- or third-most abundant species. Total fish abundance peaked in <br />1993 and was least in 1997; Shannon-Wiener Diversity was least in 1991 and changed <br />little from 1993 through 1997. No attribute of spring runoff was significantly related to <br />summer abundance of red shiner, fathead minnow, speckled dace, flannelmouth sucker or <br />channel catfish in Reach 5. Summer abundance of blue head sucker was, however, <br />significantly and positively related to four of five attributes of spring runoff. Red shiner <br />was the most abundant species in Reach 4 in all years except 1996 when fathead minnow <br />was most abundant. Speckled dace was the second-most common species in five of <br />seven years; it was third-most common in 1994 and sixth-most common in 1996 (a low <br />spring runoff and summer flow year). Total abundance of fishes in Reach 4 peaked in <br />1993 and 1995 and was least in 1997. Shannon-Wiener Diversity Index declined from <br />1991 through 1997. Summer abundance of red shiner was fairly strongly, but not <br />significantly, positively related to most attributes of spring discharge in Reach 4. <br />Speckled dace abundance was significantly and positively related to four of five spring <br />runoff attributes. Flannelmouth sucker abundance was strongly, but not significantly, <br />related to days discharge> 5000 cfs and bluehead sucker abundance was most strongly <br />related to days discharge> 8000 cfs. Abundance offathead minnow and channel catfish <br />was not related to any attribute of spring runoff. Red shiner was the most abundant <br />species in Reach 3 in all years except 1995 and 1996, when fathead minnow was most <br />abundant. Speckled dace was the second-most abundant species in all years except 1994 <br />and 1996; its abundance was least in 1996, a low spring runoff and summer flow year. <br />Similar to Reach 4, total abundance peaked in Reach 3 in 1993 and 1995 (high spring <br />runoff years) and was least in 1997. Shannon-Wiener Diversity declined from 1991 <br />through 1997. Summer abundance ofred shiner was significantly, and positively, related <br />to days spring discharge >5000 cfs. Speckled dace and bluehead sucker abundance was <br />significantly, and positively, related to four of five spring runoff attributes. Summer <br />abundance offlannelmouth sucker was most strongly related to days discharge> 5000 <br />cfs. No attribute of spring runoff was related to summer abundance of fathead minnow or <br />channel catfish. Neither Colorado pikeminnow nor razorback sucker was collected in <br />secondary channels during summer. <br /> <br />~;iq'(~,':~(f';:'~< <br /> <br />11 <br /> <br />. <br />C <br />C <br />C <br />C <br />C <br />C <br />C <br />C <br />C <br />C <br />C <br />C <br />C <br />f <br />f <br />f <br />f <br />f <br />f <br />f <br />. <br />