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About SPU
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Water System
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Habitat Conservation Plan--HCP
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Landsburg Mitigation
Sockeye Mitigation
The projects and programs explained below mitigate for the absence of Sockeye spawning opportunities above the Landsburg Dam.
Interim Sockeye Mitigation
The City has committed to provide funding to continue the operation of the existing Sockeye hatchery at Landsburg through 2008, when the replacement hatchery is expected to be operational. This facility has been in operation since 1991 under contract with the Washington Department of Fish and Wildlife and has provided the opportunity to develop and test hatchery methods at this site and to begin evaluating the performance and effects of the program.
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Replacement Sockeye Hatchery
A state of the art, replacement hatchery is planned that will increase production capacity to 34 million sockeye fry and provide improved facilities. Much work has been done by scientists and engineers to carefully design the new facilities. In addition, scientists have developed a monitoring program and an adaptive management plan that will improve our understanding of how this hatchery interacts with naturally spawning populations and will guide management decisions. Construction of the new facilities is expected to be complete in 2008.
Broodstock Collection Evaluation
The City has supported development and evaluation of measures to improve sockeye broodstock collection practices. The goals for broodstock collection are:
- • To capture a sufficient number of brood fish in a manner that helps ensure long term reproductive fitness, genetic diversity and adaptive capacity of the Cedar River sockeye population.
- • To avoid or minimize the potential of adverse impacts to naturally reproducing salmonids in the Cedar River. The capture method should minimize the risks of significant delay to upstream migrants and of damage to redds.
Sockeye Monitoring and Research
The importance of evaluating the performance and effects of the Ssockeye hatchery led to a long-term commitment of funding for monitoring activities that span the 50 year duration of the HCP. These monitoring activities are described below and were developed in consultations between the Washington Department of Fish and Wildlife, the US Fish and Wildlife Service, the National Marine Fisheries Service and the City of Seattle. As needs are identified and priorities shift, this list may change subject to input from the Anadromous Fish Committee and decisions by the Signatory parties to the Landsburg Mitigation Agreement. The long-term nature of the funding commitment provides scientists to carefully plan consistent evaluation with the confidence that funding will be available.
The sockeye monitoring program is closely associated with the hatchery’s adaptive management plan. Within the adaptive management plan, specific questions were developed that address the uncertainties associated with the performance and effects of the hatchery. The monitoring funding will be used to gather data that is useful to answering these questions and results will be carefully evaluated by scientists. These results provide the basis on which to determine whether changes in the project are needed.
Fry Condition at Release
To ensure that supplemental fry are comparable in quality to wild fry, the City will provide funding to measure fry condition factor, developmental stage and other appropriate parameters. This effort began in 2005.
Fry marking and evaluation
To monitor the performance of supplemental fry and their behavior after release, and to support the collection of general life history information on Lake Washington sockeye, the City is funding otolith marking of hatchery fry. Also included in this program is an evaluation of the success of the marking protocol by examining the otoliths of a representative sample of fry from each marked group collected prior to release. This effort began in 2001.
Fry trapping and counting
Natural and hatchery fry are counted to assess the relative performance of each group. Fry trapping at the mouth of the river is required to obtain an accurate estimate of the number of naturally produced fry that migrate from the system each year. This will provide important information such as:
- • incubation survival
- • total fry production
- • timing of fry emergence, migration and in-lake fry-to-smolt survival.
Fish Health Monitoring
Due to the presence of the infectious hematopoetic necrosis virus (IHNV- a common disease in all sockeye populations), the hatchery uses strict fish culture protocols and a comprehensive fish health monitoring program for Cedar River sockeye salmon.
Short-term Fry Rearing Evaluation
The effects of short-term rearing of sockeye fry on survival are being evaluated to provide information that can help guide future decisions concerning the operations and facilities associated with the sockeye hatchery. To match fry outmigration timing between hatchery fry and those produced in the river, protocols will be established to simulate natural timing for hatchery fry. Short term holding facilities will be developed to accommodate the distribution of fry from the hatchery, and rearing could complement temperature control to better align developmental timing of hatchery-produced fry.
Lake Washington Plankton Studies
Juvenile sockeye rear in the offshore areas of Lake Washington for a year before migrating to the ocean, during which time they feed and grow rapidly. The City is working with the University of Washington to support a better understanding of the food supply that sockeye rely on in Lake Washington.
Adult Survival and Distribution Studies
Survival and distribution studies will be done to measure the fry-to-adult survival of hatchery fish, monitor their spawning distribution in the lower river, and assess the rate at which supplemental fish might stray. Information derived from these collections will be used to evaluate the effects of time and release on adults returns and to compare hatchery and natural origin returns over time. These data will be used to evaluate and modify fry release strategies and other aspects of the supplementation program to improve performance and minimize the risks of unexpected, harmful effects on naturally reproducing Sockeye.
Phenotypic and Genetic Studies of Adults
The University of Washington conducted studies to characterize phenotypic and molecular genetic traits in Cedar River sockeye populations. This information has improved the understanding of relationships between groups of sockeye and kokanee spawning within the Lake Washington basin and allowed comparisons with founder populations. In addition, this information will be useful to compare data collected from these populations in the future for any changes that might occur.
Related links
Sockeye Hatchery
Habitat Conservation Plan- HCP
Hatchery Supplemental Environmental Impact Statement (PDF)
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