Laserfiche WebLink
<br />Perhaps the most interesting aspect of these spawning sites was <br />12 <br />their location at the head of small gravel .islands, where the water <br />flow was split. Sampling at sites similar in every way except for the <br />splitting effect revealed no humpbacks or flannelmouths, even after <br />repeated attempts. <br />Sampling for fertilized eggs at these sites was unsuccessful, being <br />greatly hamper°ed by the swiftness of the water. High turbidities made <br />actual observations of the spawning act impossible., Turbidities in <br />the Yampa increased from approximately 600 JTU's to about 1000 JTU's. <br />during the sampling period. Temperatures increased from 6°C to 10°C <br />during the same time span. <br />At Walker Wildlife Area the temperature was approximately 17°C <br />during this time with a turbidity of slightly more-than lUG JTU's. Even <br />though this water was clearer than in the Yampa River, visibility t~ras <br />limited to approximately a foot beneath the surface and na observations <br />of spawning fish were made. The Colorado River was about 12°C during <br />this period with turbidities of greater than 1000 JTU's. <br />Sampling for larval and juvenile humpback suckers has been uniformly <br />unsuccessful. Collections were made using a 15', 1/a" mesh minnow seine, <br />and a specially modified scoop shovel, covered with very fine mesh wire <br />screen. Only one larval fish was obtained in the Wildlife area with <br />repeated efforts. At this time the larva is considered to be a flannel- <br />mouth sucker. Juvenile flannel~~nouths were also readily collected with <br />the seine, but no ,juvenile humpback suckers were obtained. <br />Larval fish were collected in great numbers in the Echo Park area. <br />However, because of the extreme difficulty, if not impossibility, of <br />