1. Variations in source waters which feed
the California Current may be the mechanism which links the PDO and
climate change with ecosystem response
Bill Peterson
Senior Scientist
Newport Field Station
and
Cheryl Morgan, Hongsheng Bi, Jennifer Fisher and Jay Peterson
< “Ocean Conditions and Salmon Forecasting”

2. Today I will speak about each of these aspects of “ocean conditions”
We are contributing to salmon management by studying the ocean phase of their life history and by developing management advice based on a suite of physical, biological and ecological indicators of ocean conditions
Today I will speak about
each of these aspects of “ocean conditions”
Large scale forces acting at the local scale can influence biological process important for salmon
PDO
Local Conditions
Upwelling & SST
Spring Transition
Coastal currents
ENSO
We believe our work is an example of
an ecosystem approach to management
Local Biological Conditions 2

3. Observations Newport Line biweekly sampling since 1996 (16th year)
La Push
Queets River
Grays Harbor
Willapa Bay
Columbia River
Cape Meares
Cascade Head ^ _
Cape Falcon
Cape Perpetua
Newport
Washington
Oregon
Observations
Newport Line biweekly sampling since 1996 (16th year)
Juvenile salmon sampling in June and September since 1998 (14th year)
Historical data:
hydrography, 1960s;
plankton, ; ,
juvenile salmon,

4. Methods and Outline
Copepods with ½ m diameter 200 µm mesh net towed vertically from 100 m
Krill, fish eggs and fish larvae with 70 cm 333 µm mesh Bongo net towed obliquely
Ordination analysis of ~ 400 copepod samples collected at the station NH 05
Use X-axis scores of an ordination 4

5. Here are two types of plankton that play key roles in a salmon’s food chain: copepods and krill,
Omega-3 fatty acids
Going to add more plankton pictures throughout the talk.
KRILL 5

6. Oceanography 101

7. Circulation off the Pacific Northwest
Subarctic Current brings cold
water and northern species
to the N. California Current;
The West Wind Drift brings
subtropical water and subtropical
species to the N. California Current
Therefore, ecosystem structure
is affected by the source waters
which feed the California Current.

8. Winds and current structure off coastal Oregon:
Winter:
- Winds from the South
- Downwelling
- Poleward-flowing Davidson Current
- Subtropical and southern plankton species
transported northward & onshore -
Spring Transition in April/May
Summer:
- Strong winds from the North
- Coastal upwelling
- Equatorward alongshore transport
- Boreal/northern species transported
southward
Fall Transition in October 4 2 N 3 5 6
Newport WA OR
Off Oregon, the wind and current patterns are very seasonal.
In Winter, winds are from the south, the Davidson Current flows poleward, and downwelling causes onshore transport of surface water
The hydrography is uniform across the whole shelf
the Spring Transition occurs in about April when winds become Northerly
In Summer, we get strong North winds which sets up equatorward flow and upwelling, and
There’s strong cross-shelf physical gradients
Upwelling-favorable winds cease in about September 8

9. NMDS (Non-Metric Multidimensional Scaling):
Copepod Community Structure over 21 years
X-axis explains about 70% of the variance 9 9 9

10. Seasonal Cycles of the following:
Copepod Community Structure (x-axis scores)
Upwelling (Bakun upwelling index at 45 N
Temperature at a depth of 50 m at the NH 05 station
Salinity at a depth of 50 m at the NH 05 station

11. X-axis SCORES
UPWELLING INDEX AT 45 N
TEMPERATURE AT NH 05 AT 50 m SALINITY AT NH 05 at 50 m

12. 15 year time series of SST anomalies off Newport shows that PDO downscales to local SST
PDO and SST correlated, (as they should be.
Note the three recent periods of persistent sign changes: mid-1999, mid and mid-2007
However there are time lags between PDO sign change and SST response of ~ 3-5 months, suggesting perhaps that the PDO is an advective signal along the Oregon coast
Temperature differences usually + 1°C

13. W S Interannual Variability in Copepod Community Structure
Positive = warm water community; often in winter (W)
Negative = cold water community; usually in summer (S)
Note: 1998 and 2005 never showed a “cold water community”

14. PDO and zooplankton: copepod community composition
The sign of the PDO is associated with either warm or cold water being advected to the coast
As a consequence you
get “warm” and “cold” water zooplankton communities in coastal waters in association with positive or negative phase of the PDO, but with a few months lag.
PDO and zooplankton: copepod community composition
Warm water
community
Cold water
community 14 14

15. X-axis anomaly vs PDO
X-axis anomaly vs
Upwelling Index
X-axis anomaly vs temperature

16. Summer-averaged PDO vs summer averaged X-axis scores: 1969-1973, 1983, 1996-2010 (n = 21 years)

17. Proportion of cold water species: (Pseudocalanus, Calanus marshallae and Acartia longiremis

18. Contrasting Communities
Negative PDO = “cold-water” copepod species. These are dominants in Bering Sea, coastal GOA, coastal northern California Current
Pseudocalanus mimus, Calanus marshallae, Acartia longiremis
Positive PDO = “warm-water” copepods. These are common in the Southern California Current neritic and offshore NCC waters
Clausocalanus spp., Ctenocalanus vanus, Paracalanus parvus, Mesocalanus tenuicornis, Calocalanus styliremis
Based on Peterson and Keister (2003) 18

19. Comparisons in size and chemical composition
Warm-water taxa - (from offshore OR) are small in size and have minimal high energy wax ester lipid depots
Cold-water taxa – (boreal coastal species) are large and store high-energy wax esters as an over-wintering strategy
Therefore, significantly different food chains may result from climate shifts;
Qualitative comparison of the two groups shows that the subtropical species tend to be smaller than the cold-water taxa….
In addition, most cold-water species tend to have over-wintering strategies which involves the accumulaiton and storage of large lipid reserves composed of wax esters
To demonstrate the size comparison, I’ve plotted up the adult female carbon weight values of each of the 8 taxa in these two assemblages that we’ve been looking at….. 19

20. A working mechanistic hypothesis: source waters. . .
“Cool” Phase
Cool Phase 
Transport of boreal coastal copepods into NCC from Gulf of Alaska
Warm Phase 
Transport of sub-tropical copepods into NCC from Transition Zone offshore
“Warm” Phase
Verified in Keister et al GCB and Bi et al GRL 20

21. What problems lie ahead for salmon?
Will coastal upwelling become weaker, stronger or stay the same?
Will warming of the ocean lead to greater stratification thus reducing the effectiveness of coastal upwelling?
Will the Pacific “Decadal” Oscillation return to “Decadal”?
Will the central North Pacific Gyre expand northward and make the waters off Oregon more subtropical?
Alternatively, will expansion of the gyre make coastal upwelling more productive?
Of great concern in coastal upwelling systems is the trend toward decreased oxygen concentration and of decreased pH in waters which upwell at the coast.

22. Acknowledgements Bonneville Power Administration
U.S.GLOBEC Program (NOAA/NSF)
NOAA Stock Assessment Improvement Program (SAIP)
Fisheries and the Environment (FATE-NOAA)
National Science Foundation
Office of Naval Research
NASA
See “Ocean Conditions and Salmon Forecasting” 22

23. Oxygen in shelf waters off Newport
Hypoxia observed only on two dates in 2010: September (3rd and 9th)

24. Oxygen data from CTD casts during the September
Juv. Salmon trawl survey:
Oxygen in bottom waters from La Push to Newport in September
The stronger the upwelling, the lower the oxygen concentration
** Note: data from 2006 on Heceta Bank south of Newport
from Francis Chan/PISCO**
Widespread hypoxia (blue/purple color) in 2006 and 2007;
Virtually none anywhere in 2010