7636

• UCREFRP Catalog Number: 7636
• Author: National Research Council
• Title: Editor
• USFW Year: Series
• USFW - Doc Type: 1992
• Copyright Material: YES

28 RESTORATION OF AQUATIC ECOSYSTEMS
TABLE 1.3 Water Quality Limitations
on Fisheries of Perennial Streams
Miles
Limit Affected Percent°
Turbidity 277,000 41.6
Elevated temperature 215,000 32.3
Excess nutrients 144,000 21.6
Toxic substances 90,900 13.6
Dissolved oxygen 75,400 11.3
pH 26,000 3.9
Salinity 14,600 2.2
Gas supersaturation 5,500 0.8
Nors: Streams surveyed in 1982.
aPercent of the 666,000 miles surveyed
SouxcE: Judy et al., 1984.
percent of the stream miles were adversely affected by turbidity, 32
percent by elevated temperature, and 21 percent by excess nutrients
(Table 1.3). Water quantity problems resulting from diversions and
dams affected approximately 18 percent of the reaches (Table 1.4).
The physical limitations most frequently cited were siltation, bank
erosion, and channel modifications. Of these, siltation was cited most
often and was identified as impairirig 40 percent of the miles surveyed
(Table 1.5). This survey was conducted once uz 1977 and again in 1982.
TABLE 1.4 Water Quantity Limitations
on Fisheries of Perennial Streams
Miles
Limit Affected Percents
Diversions
Agricultural 105,000 15.8
Municipal 10,700 1.6
Industrial 3,290 0.5
Dams
Water supply 30,800 4.6
Flood control 26,900 4.0
Power 24,800 3.7
NorE: Streams surveyed in 1982.
aPercent of the 666,000 miles surveyed.
SouxcE: Judy et al., 1984.