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Juvenile salmon in Puget Sound
Proposed Synthesis Topic

Timing of juvenile chinook salmon migration through different habitat zones in the main basins of Puget Sound

Objective:
To evaluate the timing of juvenile chinook salmon migrating through different habitat zones among the main basins in Puget Sound. Timing will be compared between basins (N to S for example) and between habitat zones within basins.

Rationale:
This information should serve as a good general reference in support of current and future studies on outmigration patterns and habitat use of chinook salmon in Puget Sound. This will be a good start as a framework for evaluating the relative importance to chinook salmon of different habitats at different times of the year throughout Puget Sound.

Methods:
We will analyze all available information (for those willing to participate) relating to the timing of chinook salmon moving from Puget Sound rivers to different habitat zones (delta, nearshore, and offshore) in Puget Sound. We will focus on pulses of fish and trends in relative abundance (e.g., proportion of the peak or total catch caught at each sampling event), so as not to introduce gear inconsistency problems. We will try to standardize data as much as possible – focus on daylight sampling, or at least try to qualify potential biases introduced by differing sampling protocols (time of day, tidal stage, net deployment method, etc.). We will also need to standardize the definitions of habitat zones – e.g. freshwater, estuarine, nearshore, offshore, or other terminology. We will carry out a comparison between hatchery and wild (marked vs. unmarked) chinook if or as far as the quality of the data will allow.

Identified data needs (2001-3):
Freshwater data (for major salmon producing rivers/streams in PS):- Stream flow data, flood events
- Environmental data – water temperatures, etc.
- Spawner counts
- Wild vs. hatchery production estimates where possible
- Hatchery release records - #’s released, marking rate/type, release dates
- Smolt trap catches and trap efficiencies to identify outmigration peaks
Puget Sound data: - Environmental data (water temperatures, salinity, etc.)
- CPUE for juvenile ocean-type chinook salmon by habitat zone, sampling area, and date
- Proportions of marked to unmarked fish, type of mark - Potentially cwt return information

Potential additional analysis:
We could analyze differences in (hatchery and unmarked) chinook salmon size between basins, over time, and at different habitat zones if available data are sufficient. We could begin with sizes obtained at smolt traps.

Caveats:
This analysis only covers a small number (2-3) of years which will not necessarily give a true representation of trends over time. However, it does present the best available current dataset and sets a great framework for future refinements and improvements and will hopefully help generate further analysis, proposals, and funding.

Other information

Work is underway to expand and improve the current spreadsheet containing dataset summaries. The improved spreadsheet will include more information on data types, gear types, purpose of studies, status and availability of data, applicability to broader questions. It will be designed to facilitate sorting by topic or species of interest.



PS Salmon Synthesis Working Questions Meetings Next Steps People & Projects Links	Juvenile salmon in Puget Sound Proposed Synthesis Topic Timing of juvenile chinook salmon migration through different habitat zones in the main basins of Puget Sound Objective: To evaluate the timing of juvenile chinook salmon migrating through different habitat zones among the main basins in Puget Sound. Timing will be compared between basins (N to S for example) and between habitat zones within basins. Rationale: This information should serve as a good general reference in support of current and future studies on outmigration patterns and habitat use of chinook salmon in Puget Sound. This will be a good start as a framework for evaluating the relative importance to chinook salmon of different habitats at different times of the year throughout Puget Sound. Methods: We will analyze all available information (for those willing to participate) relating to the timing of chinook salmon moving from Puget Sound rivers to different habitat zones (delta, nearshore, and offshore) in Puget Sound. We will focus on pulses of fish and trends in relative abundance (e.g., proportion of the peak or total catch caught at each sampling event), so as not to introduce gear inconsistency problems. We will try to standardize data as much as possible – focus on daylight sampling, or at least try to qualify potential biases introduced by differing sampling protocols (time of day, tidal stage, net deployment method, etc.). We will also need to standardize the definitions of habitat zones – e.g. freshwater, estuarine, nearshore, offshore, or other terminology. We will carry out a comparison between hatchery and wild (marked vs. unmarked) chinook if or as far as the quality of the data will allow. Identified data needs (2001-3): Freshwater data (for major salmon producing rivers/streams in PS):- Stream flow data, flood events - Environmental data – water temperatures, etc. - Spawner counts - Wild vs. hatchery production estimates where possible - Hatchery release records - #’s released, marking rate/type, release dates - Smolt trap catches and trap efficiencies to identify outmigration peaks Puget Sound data: - Environmental data (water temperatures, salinity, etc.) - CPUE for juvenile ocean-type chinook salmon by habitat zone, sampling area, and date - Proportions of marked to unmarked fish, type of mark - Potentially cwt return information Potential additional analysis: We could analyze differences in (hatchery and unmarked) chinook salmon size between basins, over time, and at different habitat zones if available data are sufficient. We could begin with sizes obtained at smolt traps. Caveats: This analysis only covers a small number (2-3) of years which will not necessarily give a true representation of trends over time. However, it does present the best available current dataset and sets a great framework for future refinements and improvements and will hopefully help generate further analysis, proposals, and funding. Other information Work is underway to expand and improve the current spreadsheet containing dataset summaries. The improved spreadsheet will include more information on data types, gear types, purpose of studies, status and availability of data, applicability to broader questions. It will be designed to facilitate sorting by topic or species of interest.
Send mail to: ejduffy@u.washington.edu Last modified: 1/26/2006 2:35 PM