9528 ‎(2)‎

• UCREFRP Catalog Number: 9528
• Author: Martinez, P. and N. P. Nibbelink.
• Title: Colorado Nonnative Fish Stocking Regulation Evaluation.
• USFW Year: 2004.
• USFW - Doc Type: Grand Junction, Laramie.
• Copyright Material: NO

LIST OF FIGURES
' 1. Map of Colorado denoting the general study area west of the Continental Divide, the
regulatory study area below 6,500-feet in elevation (excluding the San Juan River basin),
the primary study area within and adjacent to critical habitat for endangered fish along
the Colorado and Gunnison Rivers, and the intensive study area along the Grand Valley
reach of the Colorado River.
' 2. Proximity analysis: if observations of fish density in backwaters are always closer to
stocking locations than to locations where the species is absent, the stocked fish maybe a
source to riverine populations. Circles =backwaters and squares =ponds.
3. Proximity analysis: if observations of high fish density in backwaters are always closer to
stocking locations than to locations where the species is absent, the stocked fish maybe a
source to riverine populations. A simple t-test can suggest significant difference.
4. Expected patterns from the modified h-scattergram analysis. Strong relationships at
particular scales indicate the potential influence of source populations of nonnative fish
species within those distances. In this example, we see a strong relationship within 200
m, but no relationship at 1000 m.
' S. Typical pattern observed in a correlogram. Sites that are close together are often
positively correlated, or they have similar densities offish. As sites become further
' away, they are no more likely to be positively or negatively related. On average, there is
no relationship. At very large distances, one can sometimes see negative correlations
where values of fish density at sites are less related than expected based on distance
' alone. This might be due to habitat factors, for example.
6. Typical pattern observed in a semivariogram. Sites that are close together are often not
' dissimilar in their densities offish. As sites become further away, they are more likely to
differ in values. At a certain distance, this difference no longer increases. The variance
at which this occurs is referred to as the sill, or maximum spatial correlation. The
distance at this point is referred to as the range, or distance to which spatial correlation
exists in the data.
' 7. Distribution of ponds, lakes and reservoirs above and below 6,500-feet in elevation west
of the Continental Divide in Colorado based on available digital spatial records. Many
waters in high-density areas are obscured by the symbol size, but concentrations of
standing water habitats remain evident.
8. A subset of ponds in the ISA of the Colorado River with respect to the 50-year and 100-
t year floodplains.
' 9. An example of ponds containing green sunfish within the ISA of the Colorado River from
river miles 175.5 to 178.8 with respect to the 50-year and 100-year floodplains.