|
<br />Mean length of blue head sucker was lowest in 2003 due to fewer large adult fish in the
<br />sample (Table 5),
<br />
<br />Table 5. Mean length of all species collected at Duffy, Yampa River 1998 to 2003.
<br />
<br />YAMPA RIVER Mean length for all fish collect in cm
<br />SEVENS A B C D E
<br />Species 1998 1999 2000 2001 2003
<br />Flannelmouth Sucker 48.4 47.8 49,8 47,5 49,4
<br />Bluehead Sucker 35.7 38,0 37,6 36,2 30,9
<br />Colorado Pikeminnow 60,8 57.4 56.4 55.5
<br />Roundtail Chub 43,5 40,7 44,2 43.4 44.9
<br />White S, + Crosses 39,7 33,1 40,6 38.2 28,3
<br />Channel Catfish 52.9 47,6 51,6 46,4 49,7
<br />Carp 59,8 67,9 48.0 68,0 80.0
<br />Smallmouth Bass 12,6 16,1 12,2 13,1 9,6
<br />Northern Pike 43,3 51,7 57,6 32.2 43,2
<br />
<br />Sevens
<br />
<br />Composition of native fish was highly consistent from 1998 to 2001 at Sevens with
<br />native fish comprising about 73% (four-year mean) of the fish over 15 cm (Table 6), In 2003
<br />native species were less than half of the sample at 42%, Flannelmouth sucker composition at
<br />Sevens ranged from 46% to 53% between 1998 and 2001, but it was 36% in 2003, Bluehead
<br />sucker composition for the first three years (1998, 1999 and 2000) averaged 2101... In 2001 it
<br />was 13% and only 2% in 2003 (Table 6). Roundtail chub was consistent at 3% to 4% of the
<br />sample in all years at Sevens (Table 6). Colorado pikeminnow were rare or absent at Sevens
<br />for all years wi th data,
<br />
<br />Table 6, Species composition at Sevens, Yampa River, 1998 -2003,
<br />
<br />YAMPA RIVER SEVENS SEVENS SEVENS SEVENS SEVENS
<br />Species 1998 1999 2000 2001 2003
<br />Flannelmouth sucker 48% 46% 50% 53% 36%
<br />Bluehead sucker 23% 18% 22% 13% 2%
<br />Roundtail chub 5% 4% 4% 3% 4%
<br />Colo, Pikeminnow 0,20% 0.20% 0,25% 0,00% 0%
<br />White S, + hybrids 11% 15% 17% 16% 36%
<br />Channel catfish 7% 7% 2% 5% 3%
<br />Carp 4% 5% 4% 4% 4%
<br />Smallmouth bass 1,0% 2,5% 0,5% 5.0% 13%
<br />Northern pike 1,3% 1,8% 0,2% 0,3% 0.4%
<br />Black crappie 0,4% 1,3% 0.1% 0% 2%
<br />Sam pie size 1391 1040 807 676 832
<br />
<br />18
<br />
<br />I
<br />I
<br />.
<br />.'
<br />I
<br />I
<br />I
<br />I
<br />I
<br />I
<br />I
<br />I
<br />I
<br />I
<br />I
<br />I
<br />I
<br />1
<br />
|