|
<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 />I
<br />I
<br />I
<br />I
<br />I
<br />I
<br />
<br />not in 1994 and 1995 are necessary to transport Colorado squawfish and razorback sucker
<br />larvae into inflow habitats from upstream river reaches.
<br />
<br />1994, lower Green River, Millard Canyon and Bonita Bend, 4-5 and 17-18
<br />June.-A total of 2,995 fish was collected in nine light trap samples (2,923) and one seine
<br />sample (72) during 4-5 June, and 5,838 in eight light trap samples (5,600) and one seine
<br />sample (238) during 17-18 June (Table 4). Nonnative minnows dominated the catch in each
<br />sampling period (> 98% of total number collected during each sampling period), with red shiner
<br />predominating (97%, GMcpe = 145.8 for light trap samples and 9.0 for the seine sample during
<br />4-5 June; 94%, 655.9, 15.4 during 17-18 June). Common carp, sand shiner, and fathead
<br />minnow were the other nonnatives collected. Native fishes collected included Gila sp.,
<br />Colorado squawfish, blue head sucker, flannel mouth sucker, and razorback sucker. A total of
<br />39 razorback sucker larvae (10.7-16.4 mm TL) was collected during 4-5 June sampling inside
<br />Millard Canyon (24 with light traps, GMcpe = 2.3; 15 by seining, GMcpe = 5.0), and eight
<br />(11.3-13.2 mm TL) during 17-18 June light trap sampling in a flooded wash at Bonita Bend
<br />(GMcpe = 0.5) (Table 7). The seine sample on 4 June inside Millard Canyon captured 29
<br />juvenile Colorado squawfish (45-120 mm TL; GMcpe = 10.0). On 17 June, seven juvenile
<br />Colorado squawfish (50-60 mm TL) were collected by seining in a sidechannel backwater at
<br />Bonita Bend (GMcpe = 0.6). None of the juvenile Colorado squawfish collected had evidence of
<br />latex marks (USFWS/LFL mark-capture study).
<br />
<br />. 1994, middle Colorado River, Shafer Canyon, Lathrop Canyon, and the Gooseneck
<br />area, 2-4 and 16-17 June.-A total of 1,582 fish was collected in nine light trap (898) and three
<br />seine samples (684) during 2-4 June, and 6,493 in eight light trap (6,178) and three seine
<br />samples (315) during 16-17 June (Table 5). Nonnative minnows dominated the catch in each
<br />sampling period (> 96% of total number collected during each sampling period), with red shiner
<br />(84%, GMcpe = 10.8 for light traps samples and 27.0 for seine samples during 2-4 June; 2%,
<br />1.2, 3.5 during 16-17 June), sand shiner (9%, 0.4, 2.0; 2%, 6.1, 0.6), and fathead minnow (4%,
<br />0.2, 1.7; 92%, 461.9, 1.3) predominating. Common carp and white sucker were the other
<br />nonnatives collected. Native fishes collected included Gila sp., Colorado squawfish, bluehead
<br />sucker, and f1annelmouth sucker. Three Colorado squawfish juveniles (30-40 mm TL) were
<br />captured in seines; two from a sidechannel backwater in the Gooseneck area (GMcpe = 0.2) on
<br />3 June, and one inside Shafer Canyon (GMcpe < 0.1) on 16 June (Table 7).
<br />
<br />1994, Colorado River inflow to Lake Powell, 9-12 and 19-20 June and 16-17
<br />July.-A total of 5,434 fish was collected in 24 light trap samples during 9-12 June, 6,417 in
<br />eight light trap samples during 19-20 June, and 23,779 in 16 light trap (22,938) and five seine
<br />samples (841) during 16-17 July (Table 6). Nonnative minnows dominated the catch in each
<br />sampling period (> 98% of total number collected during each sampling period), with red shiner
<br />(27%, GMcpe = 49.7 during 9-12 June; 79%, 234.7 during 19-20 June; 82%, 672.5 for light trap
<br />samples and 27.8 for seine samples during 16-17 July), sand shiner (8%,3.9; 1%,3.8; 2%,
<br />7.3,1.5), and fathead minnow (62%,27.6; 17%, 104.9; 15%, 141.1,4.2) predominating.
<br />Threadfin shad Dorosoma petenense, common carp, and largemouth bass Micropterus
<br />salmoides were the other non natives collected. Native fishes collected included Gila sp.,
<br />Colorado squawfish, speckled dace, and blue head sucker. Five juvenile Colorado squawfish
<br />(79-100 mm TL) were captured in seines on 17 July (GMcpe = 0.2); four were collected inside
<br />Clearwater Canyon and one was collected over a mainchannel mud flat at RK 303.2 (Table 7).
<br />None of the Colorado squawfish juveniles had latex marks.
<br />
<br />12
<br />
|