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10 Colorado squawfish catch and relationship to flow, habitat and non-natives The flow/habitat/CPE relationships were also examined with Pearson's correlations. Colorado squawfish catch rates were not closely related to habitat availability or peak flows. There were slight negative correlations between high peak flows and CPE, and slight positive correlations between fall habitat volume and CPE, however none were significant. The relationships between high peak flow and NNC CPE were strongly negative. The relationships between habitat volume and NNC CPE were barely positive. There was a slight positive relationship between NNC and CS CPE (Table 5). An interesting comparison between the Green River and Colorado River results can be made here. The peak/habitat relationships were similar, in that high peak flows were negatively correlated with habitat volume and with NNC CPE on both rivers. However, the flow/habitat/catch relationships were quite~different. Whereas on the Green River, a mild positive correlation was seen between high peak flows and CS CPE, on the Colorado, the relationship was equally negative. The very strong positive correlation between NNC CPE and habitat volume seen on the Green River, was only slight on the Colorado River; and the moderate negative correlation between NNC CPE and CS CPE on the Green River, was moderately positive on the Colorado. The conclusion drawn from the Green River data, that non-native cyprinids were limiting the occurrence of squawfish, and that habitat was only limited due to competition with the NNC, does not appear to be supported on the Colorado River. In general, the Colorado has more habitat and NNC, and fewer squawfish, than the Green River, but a positive correlation between NNC and CS, summer and fall. It is a paradox. Perhaps there may be some differences of productivity between the rivers that would affect both squawfish and NNC, but no data are currently available to test this, and the rivers are quite similar in sediment, gradient, and other physical characteristics.