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<br />552 <br /> <br />Many of these channels had very little flow at the top, and many would become isolated if flows <br />declined. Twenty-eight Colorado squawfish were collected from a site at RM 127.7 in a <br />secondary channel pool, with a depth of 4 feet. <br /> <br />Results - Crew 2: Two hundred and sixty seven Colorado squawfish were collected by Crew 2 <br />(Table 2). Colorado squawfish were collected in 53 separate samples. In 31 of these sites, more <br />than 1 Colorado squawfish was captured. Ten or more Colorado squawfish were caught in 7 <br />samples. Six of these seven sites had depth greater than 1.5 feet. In one large backwater at <br />RM25, 58 Colorado squawfish were caught in a single parallel seine haul. This is the first big, <br />deep backwater below Mexican Hat. This backwater is the same backwater that produced a wild <br />YOY Colorado squawfish in 1994: A total of eight marked individuals released at Shiprock were <br />caught by Crew 2. Colorado squawfish were collected in backwaters, low-velocity flow-through, <br />and along shorelines. Below RM 42, backwaters begin to become more prevalent. Sampling was <br />concentrated in these habitats, but was not limited to them. <br /> <br />Preliminary data suggests that the highest Colorado squawfish densities are associated with the <br />deeper and likely more persistent habitats. <br /> <br />Mark retention: Spray marks were observed on 21 of 122 (17%) Colorado squawfish captured by <br />Crew 1. Crew 2 encountered 35 (17%) marked individuals. Most spray marks that were present <br />could be seen with the naked eye, however, most of these were not detectable until close <br />examination. Handling each individual YOY Colorado squawfish while looking for a spray mark <br />next summer will result in high mortalities. <br /> <br />Habitat utilization: In the upper reaches, habitat use by Colorado squawfish was very similar to <br />that of trip 1. Many of the secondary channels contained Colorado squawfish. Colorado <br />squawfish habitat use in the lower reaches was also similar to trip 1 with one notable difference. <br />Crew 2 found far fewer Colorado squawfish in the first 25 miles of sampling. This may be a <br />reflection of the lack of persistent low-velocity habitat in the canyon section. <br /> <br />Habitat availability: Habitat availability during trip two was very similar to that observed during <br />trip 1. Flows since the last trip have been fairly stable in the San Juan River. An increase of <br />nearly 300 cfs was experienced by crew 2 during this trip. Crew 2 was moving down the river <br />behind the spike. The spike may have displaced some fish, but was not likely a major factor in <br />habitat persistence. <br /> <br />Additional sampling during the calendar year 1997 will then be coordinated with the regularly <br />scheduled UDWR nursery habitat trips (late March/early April, late August, and September) <br />(Table 1). <br /> <br />Studies Related to this SOW <br /> <br />Two components of additional research may be completed at Utah State University if time <br />permits. This research includes 1) lipid work on stocked Colorado squawfish and 2) determining <br />stomach contents of stocked Colorado squawfish. To date stocked Colorado squawfish have <br /> <br />12 <br />