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•	2008 Annual Update
•	January 2009 Forecast
•	Adult Return Data

Large–scale Ocean and Atmospheric Indicators

•	Pacific Decadal Oscillation (PDO)
•	Multivariate El Niño Southern Oscillation Index (MEI)
•	Basin-scale winds

Local and Regional Physical Indicators

•	Sea surface temperature anomalies
•	Coastal upwelling
•	Physical spring transition
•	Deep–water temperature and salinity

Local Biological Indicators

•	Copepod biodiversity
•	Northern copepod anomalies
•	Copepod community structure
•	Biological spring transition
•	June spring Chinook
•	September coho
•	Zooplankton species composition

Indicators Under Development

•	A second mode of North Pacific sea surface temperature variation
•	Phytoplankton biomass
•	Euphausiid egg concentration, adult biomass, and production rates
•	Interannual variation in habitat area
•	Forage fish and Pacific hake abundance
•	Salmon predation index
•	Potential indices for future development

Introduction to Pacific Northwest Oceanography

•	Physical oceanographic considerations
•	Climate–scale physical variability

Ocean Sampling Methods

•	Hydrography, zooplankton, and ichthyoplankton
•	Juvenile salmon sampling

Catches of Yearling Chinook in June
and Coho in September

Numbers of juvenile salmon caught during our June and September trawl surveys can serve as an index or surrogate measure of ocean survival for spring Chinook and coho salmon. Figure 21 shows catch per unit effort (CPUE) during our trawl surveys from 1998 to 2007.


Figure 21.	Average catches of juvenile coho (black bars) and spring Chinook (red bars) during trawl surveys off the coast of Washington and Oregon. Surveys were conducted in June (upper panel) and September (lower panel) from 1998 to 2007.

Catch rates were lowest for both species during 2005, which suggested that we should anticipate low smolt–to–adult return rates of coho in 2006 (we estimated ~1.5%) and also of Chinook salmon in 2007. Catches of coho in 2007 indicate returns of coho should be somewhat higher in 2008. In June 2008, catches suggested returns of adult Chinook in 2010 should be far higher, near the long–term average.

Figure 22 shows the relationship between catches of juvenile Chinook and coho and returns the following year of coho adults and Chinook jacks. In the upper panel, trawl catches of coho in September of year i are correlated with adult counts from the Oregon Production Index of hatchery coho adult returns (OPIH in year i + 1). Similarly, catches of yearling Chinook in June of year i are correlated with counts of spring Chinook jacks at Bonneville Dam in year i + 1.




Figure 22.	(Upper panel) Regression of OPIH adult coho salmon abundance on the average CPUE of juvenile coho salmon the previous September. Years indicated are for catches of juvenile fish. Adult production from the 2007 smolt year a prediction based on jack returns. The open point indicates the observed 2008 September CPUE (0.27) and predicted OPIH from the regression (479 thousand).
	(Lower panel) Regression of spring Chinook salmon jack counts at Bonneville Dam (1998–2007) vs. average CPUE of yearling Chinook salmon caught during each of our June cruises. Open point indicates observed CPUE in June 2008 (2.55) and predicted OPIH from the regression (47,816).

last modified 01/12/2009
Web site owner: Northwest Fisheries Science Center