Ocean temperature, hypoxia, and acidification: detecting the fingerprint of

climate change in California's coastal ocean

Drs. Emily B. Rivest, Sarah E. Moffitt, Tessa M. Hill June 16, 2015

Sea Surface Temperature in Coastal CA Sea surface temperature (SST, e.g. upper 20 m) is rising globally.

How it is measured: Moored and shore-based sensors, and throughout the water column

Datasets: 317 • ongoing: 48% • ≥ 50 years: 2% • ≥ 10 years: 62%

Length of time series (years)

100 75 50 25 10 1

Metadata are obscured by the extensive spatial and temporal records from the

California Cooperative Oceanic Fisheries Investigation (CalCOFI)

Temperature Time Series Data from CeNCOOS/UCSD Shore Station Hopkins Marine Laboratory

What you see here: Seasonal variability,

ENSO variability Inter-decadal variability

In El Niño years, maximum temperatures change little, but

winter minima are warmer

Biological Indicator for Temperature: Giant Kelp and Black Surfperch

0

0.1

4/19/01 1/14/04 10/10/06 7/6/09 4/1/12Blac

k Su

rfpe

rc(n

umbe

r

0.2

0.3

0.4

0.5Holdfast

h De

nsity

m

-2)

0

4

8

12

16

5/28/05 7/6/09 8/14/13Ho

ldfa

st D

iam

eter

(cm

)

DiameterFrond density

Biological indicators are complex and highly variable. Should be monitored concurrent with physical indicators.

0

25

50

75

100

4/19/01

Fron

d De

nsity

(num

ber m

-2)

30

20

15 10 5 1

Length of time series (years)

10

5 1

Dissolved Oxygen in Coastal CA Oxygen concentrations are declining in the interior of the ocean: • Ocean warming • Increasing stratification • Changing ocean

circulation

How it is measured: Moored sensors and throughout the water column in some places

Datasets: 53 • ongoing: 57% • ≥ 50 years: 0% • ≥ 10 years: 45%

(CALCOFI)

Oxygen Time Series Data from California Cooperative Oceanic Fisheries Investigations (CalCOFI)

0

1

2

3

4

5

6

7

8

9

[O2]

(ml/

L)

1950

1955

1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

2010

20 meters

300 meters

500 meters

20 meters

300 meters

500 meters

CalCOFI is documenting the decline of O2 concentrations in subsurface waters

(Bograd et al., 2008)

Biological Indicator for Oxygen: Humboldt Squid

©2003 MBARI

Zeidberg and Robison, 2007

Consequence of oxygen loss in the interior of the California Current:

Invasion of predatory Humboldt Squid

10 7 6 4 3 1

Length of time series (years)

Ocean Acidification in Coastal CA The ocean is acidifying as it absorbs anthropogenic CO2. Consequently, pH and carbonate ion concentrations are decreasing.

How it is measured: Moored, underway, and shore-based sensors record various carbonate chemistry parameters, usually pH and/or pCO2.

Datasets: 28 • ongoing: 25% • ≥ 50 years: 4% • ≥ 10 years: 11%

7

7.2

7.4

7.6

7.8

8

8.2

8.4

8.6

11/1/12 3/3/13 7/3/13 11/2/13 3/4/14 7/4/14 11/3/14 3/5/15 7/5/15

Seaw

ater

pH

(tot

al sc

ale)

SeapHOx pH

Bottle data

Ocean Acidification Time Series Data from Bodega Marine Laboratory (BML)

Bodega Marine Lab is measuring

carbonate chemistry in coastal ocean,

producing data with signals of seasonal

upwelling.

Fall Spring Fall

Biological Indicator for Ocean Acidification: Pteropods

Pteropod monitoring in plankton community

PMEL, NOAA

Pteropod shells dissolve when exposed to acidified seawater (we know this from laboratory experiments). This organism is an acidification “canary”.

California is a global leader We want to continue to be the leader for documenting

impacts of climate change in coastal marine ecosystems

How can we do this? By supporting: • Existing time series to prevent data gaps • Data collection distributed across CA • Expansion of OA monitoring sensor networks • Co-location collection of abiotic and biotic

data

What is ocean acidification (OA)?

The ocean absorbs ~28% of carbon dioxide emitted by industry and deforestation.

Sarah R. Cooley (scooley@whoi.edu)

Carbon Dioxide (CO2)

Climate change

Ocean acidification

• Harder to calcify skeletons and shells • Disturbed acid/base physiology

Ocean temperature, hypoxia, and acidification: detecting the fingerprint of climate change in California's coastal oceanSea Surface Temperature in Coastal CATemperature Time Series�Data from CeNCOOS/UCSD Shore Station Hopkins Marine LaboratorySlide Number 4Slide Number 5Oxygen Time Series�Data from California Cooperative Oceanic Fisheries Investigations (CalCOFI)Biological Indicator for Oxygen: Humboldt SquidSlide Number 8Slide Number 9Slide Number 10Slide Number 11What is ocean acidification (OA)?Slide Number 13