8180

• UCREFRP Catalog Number: 8180
• Author: Hamilton, S. J.
• Title: Hypothesis of Historical Effects From Selenium on Endangered Fish in the Colorado River Basin.
• USFW Year: 1999.
• USFW - Doc Type: \
• Copyright Material: YES

Table 1. Historical events in the decline of endangered f"1Sh in the Colorado River basin.

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Date

Event

1881

1886

1890

1891

1909

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1911

1912

1915

1920

Grand Valley first settled (Butler et al., 1989).

First irrigation water from private project delivered in Grand Valley, CO (Butler el ai, 1989).

12,140 ha of land irrigated in Uncomphagre and Gunnison river areas (Butler el al., 1991).

Native fish abundant in Colorado River basin (Jordan, 1891).

346 kIn of irrigation drains in Gunnison Valley (Wiltizus, 1978).

Until 1911, Colorado pikeminnow, razorback sucker and bonytail abundant in lower Colorado River basin and collect in

drainage ditches for fertilizer (Miller, 1961).

Federal Grand Valley Project authorized (Butler el al., 1989).

Razorback sucker uncommon in Uncomphagre, Gunnison, and upper Colorado rivers (Ellis, 1914).

First federal irrigation water delivered in Grand Valley (Butler el al., 1989).

1925 Some people note decline of razorback sucker in lower Colorado River basin (Dill, 1994).

Razorback sucker, Colorado pikeminnow and bony tail found in Dolores River (Quartarone, 1993).

1930 Razorback sucker, Colorado pikeminnow, and bony tail decline in lower Colorado River (Dill, 1944).

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