Fish Passage Center; Columbia Basin Fish and Wildlife Authority, 2003 Annual Report.
- Columbia Basin Fish and Wildlife Authority, Fish Passage Center, Portland, OR
The runoff volumes in 2003 were below average for the January to July period above Lower Granite Dam (79%) and The Dalles Dam (82%). The year 2003 hydrosystem operations and runoff conditions resulted in flows that met the spring seasonal Biological Opinion flow objectives at Lower Granite Dam, McNary Dam and Priest Rapids Dam. However, summer seasonal flows at Lower Granite Dam and McNary Dam were considerably below the Biological Opinion objectives of 50.7 Kcfs at Lower Granite Dam and 2000 Kcfs at McNary Dam. Actual summer seasonal flows were just 32.3 Kcfs and 135.5 Kcfs, respectively. In most instances spill was provided as described by the Biological Opinion program for fish passage, within the constraints of the State waivers for total dissolved gas supersaturation levels. Spill was altered during spill testing and most notably during the month of August at Ice Harbor dam. At this project spill was modified from a 24-hour program to a 12-hour nightly spill period pending the evaluation of studies being conducted in-season. Spill was not returned to full implementation of the Biological Opinion levels even after data showed that spillway passage had the highest associated fish survival. This experience demonstrated the difficulty of managing the hydrosystem for fish passage based on preliminary data and data collected in-season. Increased hatchery releases and higher wild fish production resulted in a population of yearling chinook at Lower Granite Dam being one of the highest observed in recent years. However, the increased hatchery production may have been offset to some extent by decreased survival from release to Lower Granite Dam as suggested by the lower than average survival observed for the PIT tagged trap released fish to Lower Monumental Dam. Travel times were also longer for hatchery spring chinook compared to recent past years. The short duration of high flows that occurred in the Lower Snake River was too late for yearling chinook, but likely was a benefit for steelhead. Survivals for spring fish in the Lower Granite to McNary Dam and the McNary to Bonneville Dam reach were similar to recent years. Returning numbers of adult spring and summer chinook, coho and steelhead were less than observed in 2002, but far exceeded the ten-year average return numbers. Sockeye numbers were less than both the 2002 returning adults and the ten-year average number. However, fall chinook numbers surpassed all previous counts at Bonneville Dam since 1938. In 2003, about 81 million juvenile salmon were released from Federal, State, tribal or private hatcheries into the Columbia River Basin above Bonneville Dam. This was slightly less than the number released last year, but about average for the past several years.
- Research Organization:
- Columbia Basin Fish and Wildlife Authority
- Sponsoring Organization:
- United States. Bonneville Power Administration.
- DOE Contract Number:
- 00004288
- OSTI ID:
- 850181
- Report Number(s):
- DOE/BP-00004288-2; R&D Project: 199403300; TRN: US200518%%184
- Country of Publication:
- United States
- Language:
- English
Similar Records
Fish Passage Center; Columbia Basin Fish and Wildlife Authority, 2004 Annual Report.
Fish Passage Center; Columbia Basin Fish and Wildlife Authority, 2000 Annual Report.