Carbaryl, Carbofuran, and Methomyl - National Marine Fisheries ...

The Bonneville Power Administration (BPA), an agency of the U.S. Department of
Energy, wholesales electric power produced at 31 federal dams (67% of its production)
and non-hydropower facilities in the Columbia-Snake Basin. The BPA sells about half
the electric power consumed in the Pacific Northwest. The federal dams were developed
over a 37-year period starting in 1938 with Bonneville Dam and Grand Coulee in 1941,
and ending with construction of Libby Dam in 1973 and Lower Granite Dam in 1975.
Development of the Pacific Northwest regional hydroelectric power system, dating to the
early 20 th century, has had profound effects on the ecosystems of the Columbia River
Basin (ISG 1996). These effects have been especially adverse to the survival of
anadromous salmonids. The construction of the FCRPS modified migratory habitat of
adult and juvenile salmonids. In many cases, the FCRPS presented a complete barrier to
habitat access for salmonids. Approximately 80% of historical spawning and rearing
habitat of Snake River fall-run Chinook salmon is now inaccessible due to dams. The
Snake River spring/summer run has been limited to the Salmon, Grande Ronde, Imnaha,
and Tuscanon rivers. Damming has cut off access to the majority of Snake River
Chinook salmon spawning habitat. The Sunbeam Dam on the Salmon River is believed
to have limited the range of Snake River sockeye salmon as well.
Both upstream and downstream migrating fish are impeded by the dams. Additionally, a
substantial number of juvenile salmonids are killed and injured during downstream
migrations. Physical injury and direct mortality occurs as juveniles pass through
turbines, bypasses, and spillways. Indirect effects of passage through all routes may
include disorientation, stress, delays in passage, exposure to high concentrations of
dissolved gases, warm water, and increased predation. Non-federal hydropower facilities
on Columbia River tributaries have also partially or completely blocked higher elevation
spawning.
Qualitatively, several hydromodification projects have improved the productivity of
naturally produced Snake River fall Chinook salmon. Improvements include flow
augmentation to enhance water flows through the lower Snake and Columbia Rivers
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