Transcript Introduction - UW Program on Climate Change

Introduction
UWHS Oysters and Ocean Acidification Module
Developed by Hilary Palevsky
([email protected])
Pg C/yr
Carbon emissions and sinks
IPCC AR5, Figure 6.8
Absorbing CO2 changes ocean pH
Hawaii (Mauna Loa)
South Pole
Hawaii (ALOHA)
Bermuda (BATS)
Canary Is. (ESTOC)
IPCC AR5, Figure SPM.4
What is pH all about anyway?
• pH = -log[H+]
• Decrease in pH =
increase in acidity
• Logarithmic scale
– A decrease of 1 unit is a
10× increase in [H+]
– A decrease of 0.1 unit
(observed in the ocean
between 1750 and today)
is a 26% increase in [H+]
Ocean carbonate chemistry
CO2 dissolution in water:
CO2 + H2O ↔ H2CO3
H2CO3 ↔ H+ + HCO3HCO3- ↔ H + + CO32What happens to [H+] as
CO2 dissolves?
How does this change pH?
How does acidification affect
CaCO3 shells?
Forming CaCO3 shells:
Ca2+ + CO32- ↔ CaCO3
Ω = [Ca2+][CO32-]/Ksp
When Ω < 1, water is
undersaturated and
CaCO3 will dissolve
Calcifying organisms
Geoduck
Blue mussel
Pink calcifying algae
Urchins
Dungeness crab
Juvenile king crab
• Examples of Puget Sound organisms that build
shells, skeletons or other hard parts from CaCO3
Images from Washington State Blue Ribbon Panel on Ocean Acidification Report, 2012
Pteropods: OA poster child
•
•
•
•
Zooplankton, swimming snail
Food for young salmon
Shells dissolve in low pH waters
Already observed shell
dissolution damage in Pacific
Ocean off US west coast
Pteropods dissolve in water with pH and carbonate chemistry expected for 2100
Shellfish industry in Washington
• Washington is the
country’s leading producer
of farmed oysters, clams
and mussels
• $270 million annually
from shellfish aquaculture
• 3,200 jobs created by
shellfish growers
Washington State Blue Ribbon Panel on Ocean Acidification Report, 2012
Impact on oyster growers in the Pacific
Northwest
WA Blue Ribbon Panel Report, 2012
Your problem: How is ocean
acidification affecting oyster larvae?
Photos: Steve Ringman, The Seattle Times
• Use data from Whiskey Creek Hatchery to
investigate the relationship between water
chemistry and oyster larval growth
• Explain your findings and provide advice to the
hatchery managers
Part 1
UWHS Oysters and Ocean Acidification Module
Developed by Hilary Palevsky
([email protected])
How do changes in Ω affect oyster larvae?
Relative larval production
Relative larval production dependence on Ω
0.60
R² = 0.5568
0.40
0.20
0.00
-0.20
0.5
1
1.5
2
-0.40
-0.60
-0.80
-1.00
-1.20
Ω, aragonite saturation state
2.5
How do changes in Ω affect oyster larvae?
Whiskey Creek Hatchery,
Netarts Bay, OR
Barton et al., 2012
Taylor Shellfish
Hatchery,
Dabob Bay, WA
WA Blue Ribbon Panel Report
Part 2
UWHS Oysters and Ocean Acidification Module
Developed by Hilary Palevsky
([email protected])
Photosynthesis and respiration
CO2 + H2O ↔ CH2O + O2
Photosynthesis
Respiration
• Photosynthesis requires sunlight
• Respiration occurs both day and night
How do you expect photosynthesis and
respiration to change pH and Ω?
Coastal upwelling
• When winds blow along to the south along the
coast, surface water is pushed offshore
• This causes deep water to upwells to the surface
Properties of deep water brought to
the surface by upwelling
• Colder
• Saltier
• More CO2
(respiration but no
photosynthesis in
deep water)
Feely et al., 2008
8.2
3
8.1
2.5
pH
8
2
7.9
1.5
7.8
1
7.7
0.5
7.6
7.5
7/6
7/7
7/8
7/9
7/10
7/11
7/12
0
7/13
Omega
One week of pH and Ωaragonite showing
diurnal cycle
pH
Omega
200
Upwelling Index
Upwelling
Index
100
Temp. (°C)
0
5/27
-100
18
6/6
6/16
6/26
7/6
7/16
7/26
8/5
35
Temperature and Salinity
33
31
13
29
Salinity
300
27
8
5/27
8.1
25
6/6
6/16
6/26
7/6
7/16
7/26
Temp
Salinity
8/5
pH
8
1.8
7.9
1.3
7.8
7.7
5/27
Omega
pH and Ω 1-day running mean
pH
0.8
6/6
6/16
6/26
7/6
7/16
7/26
8/5
Omega
Part 3
UWHS Oysters and Ocean Acidification Module
Developed by Hilary Palevsky
([email protected])
Future projections
IPCC AR5 SPM.7
RCP 2.6
(low future
emissions)
IPCC AR5 SPM.8
RCP 8.5
(high future
emissions)
Future projections
IPCC AR5 Figure 6.29
Future projections for the US west coast
Gruber et al., 2012