Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Hazard assessment of inorganics to endangered fish in the San Juan River, New Mexico

Conference ·
OSTI ID:382724
;  [1]
  1. National Biological Service, Yankton, SD (United States)

Acute toxicity tests were conducted with larval Colorado squawfish (Ptychocheilus lucius) and razorback sucker (Xyrauchen texanus) in a constituted water quality simulating the San Juan River near Shiprock, New Mexico. Tests were conducted with arsenate, copper, selenate, selenite, zinc, and five mixtures of seven to nine inorganics simulating environmental mixtures reported for sites along the San Juan River (Ojo Amarillo Canyon, Gallegos Canyon, Hogback East Drain, Mancos River, and McElmo Creek). Razorback suckers were significantly more sensitive to arsenate, selenate, selenite, Hogback East Drain mixture, and Ojo Amarillo Canyon mixture than were Colorado squawfish. The Gallegos Canyon mixture had greater than additive, i.e., synergistic, toxicity to both species, the Ojo Amarillo Canyon mixture had less than additive, i.e., antagonistic, toxicity to both species, and the Mancos River and McElmo Creek mixtures had additive toxicity to both species. The Hogback East Drain mixture had additive toxicity to Colorado squawfish, but synergistic toxicity to razorback suckers. The major toxic component in the five mixtures was copper. Comparison of 96-hour LC50 values with a limited number of environmental water concentrations from the San Juan River revealed high hazard ratios for copper and all five environmental mixtures. The high hazard ratios suggest inorganic contaminants could adversely affect larval Colorado squawfish and razorback suckers in the San Juan River at sites receiving elevated inorganics.

OSTI ID:
382724
Report Number(s):
CONF-9511137--; ISBN 1-880611-03-1
Country of Publication:
United States
Language:
English