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Table 1. (continued). e Variable Assumption and sources Vs Temperatures which allow larval white suckers optimum growth are excellent (McCormick et al. 1977) and temperatures in which the larvae can be commonly found are good (Marcy 1976). Tem- peratures which are lethal, cause high incidence of deformities, or allow little or no growth are considered poor (McCormick et al. 1977). V6 Temperatures which allow maximum hatching rates and at which collection of viable eggs occurs are good to excellent (McCormick et al. 1977; Fuiman 1978; Kreiger 1980; Curry 1979). If hatching rates are diminished, the temperatures are con- sidered fair and if hatching rates are very low or nonexistent the temperatures are judged poor. V7 White suckers have not been observed spawning in areas of no flow or in very fast (> 90 cm/sec) riffle areas, therefore, these riffle velocities are judged as poor (Dence 1948; Symons 1976). White suckers, when in fast waters, preferred areas of moderate velocities (30 to 49 cm/sec) (Symons 1976) and were observed spawning at velocities of 50 to 59 cm/sec (Curry 1979), these velocities are assumed excellent. f Va Spawning is reported most often to take place in shallow riffles (Dence 1948; Geen et al. 1966). Spawning has been reported to take place at depths of 30 cm (Nelson 1968) and 20 to 25 cm (Curry 1979) and Fuiman (1978) has collected white sucker eggs at depths of 15 to 20 cm. Depths at which eggs were deposited or spawning observed are considered excellent. Increasing depths and decreasing depths were assumed to exhibit less optimum to poor conditions, respectively. Vg Propst (1982b) reported a high correlation between pool cover and white sucker populations. Total cover is considered good and cover of 40 to 75% is assumed excellent. An absence of stream cover is assumed poor. 16 ~