What caused the Sacramento River fall

Chinook stock collapse?

(NOAA tech memo 2009)

“In conclusion, the development of the Sacramento-San Joaquin watershed has greatly simplified and truncated the once-diverse habitats that historically supported a highly diverse assemblage of populations. The life history diversity of this historical assemblage would have buffered the overall abundance of Chinook salmon in the Central Valley under varying climate conditions. We are now left with a fishery that is supported largely by four hatcheries that produce mostly fall Chinook salmon.”

Climate and Pacific salmon

ENVIR/ATMS/ESS/SMA 585AFebruary 3, 2011

Outline

the NW salmon crisis A bit about biodiversity of salmon and

the role of climate in salmon habitat ENSO and PDO Global warming impacts

The Northwest Salmon Crisis: The Northwest Salmon Crisis: commercial landings in the Columbia River 1863-1993commercial landings in the Columbia River 1863-1993

1950

1920’s

1870’s

19931863

Mill

ions

of

poun

ds la

nded

10

20

30

1988

1977

1911

NRC (1996): Upstream: Salmon and Society in the Northwest

Why the decline?

The industrial economy+natural variability fur trade, mining, timber harvests, grazing,

irrigation, dams, overfishing, poor hatchery practices, poor management and poor ocean conditions (Lichatowich 1999: Salmon Without Rivers)

We have reduced opportunities for wild salmon at every stage of their lifecycle (loss of habitat), and we have reduced their capacity for adaptation (loss of

species diversity, abundance and distribution through harvests, hatcheries,

and habitat loss and degradation)

The climate/habitat/biodiversity ratchet

(Lawson 1993)

Climate Climate variabilityvariability

Habitat quality and quantity, species diversity

Fish Population

20001900 1950

++

Harley Soltes/Seattle Times

A highly simplified salmon lifecycle

Adaptive TraitsAdaptive Traits(Temporal)(Temporal)

There is a diversity of peak smolt migration timing for wild coho for west coast populations

Adaptive TraitsAdaptive Traits(Spatial)(Spatial)

Chinook salmon ocean migration patterns vary by population

Different populations have evolved different ways of living in different

environments

Fraser sockeye spawningtiming vs. incubation temperature

Spawning timing

Incu

bat

ion

tem

per

atu

re

There are clear life history traits shaped by habitat

• spawning timing, freshwater rearing periods, smolt migration timing, ocean migration patterns

habitat is the template upon which life history

diversity is forged

Freshwater habitat has seasonal rhythms that vary with physiographic setting

Oct Feb Jun

Skagit

Puyallup

Skokomish

Oct Feb Jun

Oct Feb Jun

Puget Sound Precip

Oct Feb Jun

Ocean TypeOcean Type

Stream TypeStream Type

(Estuary)

(Ocean)

(Fall)

(Spring)

ChinookChinookLife HistoryLife History

Habitat = seasonal rhythms + variability

Climate and freshwater habitat issues

Winter floods: scouring incubation period flows, heavy siltation of redds, flushing alevins, fry and parr out of favored habitat

Spring snowmelt freshet: some populations have smolt migrations timed to “ride” the high flows to the ocean

Low summer/fall streamflow + high stream temperature:

Increased physiological stress, susceptibility to diseases and parasites, reduced rearing and spawning habitat, thermal blocks to adult migration

At extreme high temperatures (T > 21°C for prolonged period) salmon die

Coastal upwelling

Spring and summer winds from the north cause upwelling of cold, nutrient rich waters into the coastal waters of the western US

Winter winds and pressure over the North Pacific

Summer winds and pressure over the North Pacific

“Aleutian Low” “Subtropical High”

HH

LL

The average year in winds

Fickle winds can cause large changes in upwelling habitat on short time-space

scales

17.5C on July 1417.5C on July 14

~11C on July 20~11C on July 20

Stonewall Banks Buoy SSTStonewall Banks Buoy SSTJune 18 - August 2 2005June 18 - August 2 2005

20 July 2005 SST NOAA CoastWatch image

Buoy SST plot courtesy of Pete Lawson

June July August

Sept 1997 El Niño Sept 1998 La NiñaSept 1998 La Niña

Year-to-Year changes associated with ENSO variations Year-to-Year changes associated with ENSO variations can also be large -- note the 3 to 4 C decline in coastal can also be large -- note the 3 to 4 C decline in coastal

SSTs between Septembers of 1998 and 1999SSTs between Septembers of 1998 and 1999

17

18

15

13

14

12

Warm extremesEl Niño

cold extremesLa Niña

An intense An intense Aleutian Low Aleutian Low warms and warms and stratifies the stratifies the coastal oceancoastal ocean

Typical winter winds and jet Typical winter winds and jet stream during El Nino wintersstream during El Nino winters

Cool water, weak stratificationhigh nutrients, a productive “subarcticsubarctic” food-chain with abundant forage fish and few warm water predators

Warm stratified ocean, fewnutrients, low productivity “subtropicalsubtropical” food web, a

lack of forage fish and abundant predators

Recently, warm ocean years have generally been poor for NW chinook, coho and sockeye, but good for Puget Sound pink and chum salmon.

Upwelling food webs Upwelling food webs in our in our

coastal oceancoastal ocean

West Coast Nekton in 1997-98

Major changes in the Major changes in the distribution of pelagic distribution of pelagic fishes and squid lead to fishes and squid lead to important important ““top-downtop-down”” impacts on coastal food-impacts on coastal food-webs toowebs too

A recent visitor that seems to like it here - prior to 1997 they’d never

been observed in PNW waters, but were reported to be abundant in

California waters in the 1930s.

• Humboldt Squid, Jumbo flying squid, Diablos rojos (Dosidicus Gigas): a voracious predator that can reach up to 2m in length and weigh up to 45 kg

Image from http://www.mbari.org/news/news_releases/2007/dosidicus.html

New predator-prey interactions

A black bear with a salmon near Tofino, Vancouver Island

A black bear with a humboldt squid, also near Tofino, Vancouver Island

ENSO and salmon habitatEl Niño winters:

intense Aleutian Low low snowpack and streamflow

Weak tropical trade winds, coastally trapped warm water currents

warmed, strongly stratified upper ocean for PNW coast

La Niña winters: weak Aleutian Low,

abundant snowpack and streamflow

intense tropical trade winds, coastally trapped cold water currents

cooled, weakly stratified upper ocean for PNW coast

Decadal variations in spring upwelling

In the 20th C. springtime upwelling winds varied strongly at interdecadal timescales (partly in step with the PDO)

Schwing et al. 2006: GRL

stro

ng

wea

k

0

1000

2000

3000

4000

5000

6000

Biomass

1925 1935 1945 1955 1965 1975 1985 1995 2005

NA sockeye AS sockeye NA pink

NA pink hatchery AS pink AS pink hatchery

NA chum NA chum hatchery AS chum

AS chum hatchery

Data from Eggers; Figure from Schindler et al (2008): Fisheries

Pacific Decadal Oscillation (PDO)

Climate variability has a powerful influence on salmon production -- just a 1 to 2˚C swing in ocean

temperatures is associated with a doubling of salmon biomass between “warm” and “cool” eras of the Pacific

Decadal Oscillation

Total Pacific salmon biomass

HatcheryHatcherycontributionscontributions

Global Warming Impacts on freshwater habitat

Changing Watershed Classifications:Transformation From Snow to Rain

* Based on Composite Delta Method scenarios (multimodel average change in T & P)

Source: Alan Hamlet, Columbia Basin Climate Change Scenarios Project Map: Rob Norheim

• Warming winter temperatures will cause snowlines to rise, a shift to more rainfall

(and direct runoff) and less snowpack and snowmelt runoff in spring

Dramatic changes in snowmelt Dramatic changes in snowmelt systemssystems

Snowmelt rivers become transient basins Transient basins become rainfall dominant

Mantua et al 2010: Climatic Change

Summer base flows are projected to drop Summer base flows are projected to drop substantiallysubstantially (5 to 50%) for most streams in western WA and the Cascades

The duration of the summer low flow season is duration of the summer low flow season is also projected to increase in snowmelt and also projected to increase in snowmelt and transient runoff riverstransient runoff rivers, and this reduces rearing habitat

Mantua et al 2010: Climatic Change

Models project more winter floodingmore winter flooding in sensitive “transient runoff” river basins that are common in the Cascades

Likely reducing survival rates for incubating eggs and rearing parr

Mantua et al 2010: Climatic Change

Western Washington’s “maritime” summer climate becomes as warm as today’s interior Columbia Basin,

temperatures in the interior Columbia Basin become as warm as today’s Central Valley in California

1980s

Mantua et al 2010: Climatic Change

Thermal stress season

Extended periods with weekly average water temperatures > 21C the season of thermal

migration barriers for migrating salmon predicted to last up to 12 weeks in the mainstem Columbia River

Number of weeks T > 21C

Weeks with T > 21C

Mantua et al 2010: Climatic Change

Back to the Pacific

will global warming degrade marine habitat for salmon?

IPCC multi-model ensemble SST projections

Under a conservative (A1B) greenhouse gas emissions scenario, climate models typically project 2 to 3 ºC warming by 2090s for the north Pacific

From the Seattle Post-Intelligencer, October 20, 2005

Species distributions change with temperature

134 lb marlin caught 40 mi. west of Westport, WA, Sept 2, 2005

Photo obtained from the Seattle Times web-archives

Global warming and Coastal Cooling?

Because the land warms faster than the ocean, this may intensify the sea level pressure gradient between the oceanic Highoceanic High and Thermal LowThermal Low over land, which would intensify upwelling winds… which would cool the ocean even more, and further increase the temperature contrast

“ThermalLow”Over

Warm land

“OceanicHigh”Over

Cooler water

H L

See Bakun, Patterns in the Ocean, p 223-227

West

coast

West

coast

IPCC multi-model ensemble summer and winter SLP

projections

Taken as a group, IPCC climate models project trends to a stronger North Pacific High in summer, and a deeper Aleutian Low in winter

2090s A1B IPCC models

JJA

DJF

H

H

LL

• Reduced calcification rates for calcifying (hard-shelled) organisms and physiological stress

• Shifts in phytoplankton diversity and changes in food webs

• Reduced tolerance to other environmental fluctuations

• Potential for changes to fitness and survival, but this is poorly understood

What are the biological implications of What are the biological implications of ocean acidification?ocean acidification?

Barr

ie K

ovis

h

Pink Salmon

Coccolithophores

Vic

ki F

ab

ry

Pteropods

Copepods

AR

CO

D@

ims.

uaf.

ed

u

(Slide provided by Dick Feely, NOAA)

Lots of uncertainty in future ocean habitat for salmon

Upwelling winds, El Niño and the Pacific Decadal Oscillation - will these behave as they have in the past century?

How will ocean acidification impact salmon food-webs?

Cumulative impacts across the full life-cycle of salmon

Early snowmelt;

lower+warmer

summer/fall flows

Floods, warmer temps

Warmer, more stratified, but

upwelling? Acidification?

Warmer, lowerstreamflow

Impacts will vary depending on life history and watershed types

Low flows+warmer water = increased pre-spawn mortality for summer run and stream-type salmon and steelhead

Clear indications for increased stress on Columbia Basin sockeye, summer steelhead, summer Chinook, and Lake Washington sockeye and Chinook, and coho and steelhead more generally

Harley Soltes/Seattle Times

Increased winter flooding in transient rain+snow watersheds

a limiting factor for egg-fry survival for fall spawners + coho and steelhead parr overwinter survival in high-gradient reaches

Increased winter flooding in transient rain+snow watersheds

a limiting factor for egg-fry survival for fall spawners + coho and steelhead parr overwinter survival in high-gradient reaches