8068

• UCREFRP Catalog Number: 8068
• Author: Bestgen, K. R., R. T. Muth and M. A. Trammell.
• Title: Downstream transport of Colorado squawfish larvae in the Green River drainage
• USFW Year: 1998.
• USFW - Doc Type: temporal and spatial variation in abundance and relationships with juvenile recruitment.
• Copyright Material: NO

' Fall recruitment ofjuveniles.-- Fall abundance of juvenile Colorado squawfish from
' 1990-1996 was measured by other biologists using the Interagency Standardized Monitoring
Program (ISMP) protocol (McAda et al. 1996) in which the first two backwaters > 30 m2 in area
' and > 30 cm deep encountered in each 8 RK reach of the middle (322-515 RK) and lower (0-193
RK) Green River were sampled with two non-overlapping hauls with a 4.6 m long seine (3.2 mm
' mesh). Area seined and number and TL of Colorado squawfish captured were recorded.
Densities of Colorado squawfish were calculated per backwater sampled by dividing number of
' Colorado squawfish caught by area sampled. Densities were transformed (loge [density + 1 ]),
averaged over the reach, and back transformed to yield a geometric mean abundance (McAda et
' al. 1996). Abundance of Colorado squawfish juveniles in the lower Green River and middle
Green River was plotted as a function of the transport abundance of larvae for the lower Green
' River (1991-1996) and lower Yampa River (1990-1996) spawning areas, respectively, to
determine if there was a relationship between the number of larvae transported to nursery areas
' and recruitment in fall.