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About SPU
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Water System
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Habitat Conservation Plan--HCP
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Sockeye Hatchery
Existing Hatchery Results
The interim sockeye hatchery began operating at Landsburg sin 1991 in an attempt to halt the decline of sockeye that began in the mid-1980s. At about the same time, a research initiative was launched to examine the causes of the decline of sockeye in L. Washington by learning more about their ecology. This research included evaluation of the food supply, predation, the effects of flow on the survival of sockeye in the Cedar River. Since these investigations were initiated, various agencies have undertaken additional research to expand our understanding of factors affecting sockeye and how they interact with other species. For further information, see the FEIS and SEIS documents.
Operation of the interim hatchery has provided opportunity to evaluate culture methods that are unique to sockeye culture and test their effectiveness. Methods that were developed in Alaska to control a viral disease (IHN virus) common to all sockeye populations have proven effective at the Landsburg site. In addition, useful information on incubator performance, water supply, incidence of virus, development rates, emergence timing, broodstock collection and other parameters has been generated through the operation of the interim hatchery. This experience is valuable in guiding design and program decisions for the replacement hatchery.
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hatchery-produced fish as they grow and ultimately return as adults.
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The operation of the interim hatchery has also provided an opportunity to evaluate operating protocols and to examine returns for differences with natural origin returns. All sockeye fry released from the Landsburg hatchery have been marked since the program began in 1991. These marked fish have provided the opportunity to identify
Recovery of the adult carcasses and removal of the marked bone (otolith) in the fish's head provides the basis for determining the origin of the fish through banding patterns that are established during incubation. Otolith marking and sampling have allowed the following analyses to be initiated:
- • Estimates of annual wild and hatchery sockeye fry production from the Cedar River. WDFW has completed estimates of outmigrants by origin through 1999 and have preliminary estimates for 2005.
- • Surveys of Bear Creek, a northern tributary to Lake Washington, were done in three years (1998-2000) to determine to what extent hatchery-produced sockeye were straying into that system. The concern is that if the level of straying is too great, that the genetic composition of the Bear Creek sockeye population could be altered. WDFW issued a paper in January, 2001, entitled "Straying by Cedar River Hatchery-Produced Sockeye Salmon to Big Bear Creek, WA" by Kurt Fresh, Steve Schroder, Eric Volk and Jeff Grimm. No Cedar River hatchery marked fish were found among the 1,251 fish that were sampled during the three-year study period.
- • Otoliths have been collected from carcasses in the Cedar River each year since 1995. WDFW issued a final report (Fresh et al 2003) describing their findings on sockeye returns sampled through 2000. The authors concluded that
- • females returning to the interim hatchery were mostly smaller than those produced in naturally that were of the same age
- • there were differences in where hatchery and natural returns spawned in the river
- • that hatchery broodstock tends to be taken during the early and middle portions of the sockeye returns
- • no differences in run timing of hatchery and natural returns were found
- • no differences in the age that sockeye mature to spawn were found between hatchery and natural returns
These results and others are being used to guide the design and operating protocols for the replacement hatchery and to identify areas where the monitoring and adaptive management program should focus. More information and discussion of possible causes of the results, can be found in the paper by Fresh et al. 2003, the FEIS, FSEIS and various reports or publications listed in these documents.
Related links
Sockeye Mitigation
Habitat Conservation Plan- HCP
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