Oysters and Ocean Acidification (OA). Gimenez_NewOrl… · Oysters and Ocean Acidification (OA)...
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Oysters and Ocean Acidification (OA) WRAC Iria Gimenez, on behalf of Dr. George G. Waldbusser Gulf States Marine Fisheries Commission "Gulf of Mexico Oysters, the Industry, and the Future“ October 13, 2016
Transcript of Oysters and Ocean Acidification (OA). Gimenez_NewOrl… · Oysters and Ocean Acidification (OA)...
Oysters and Ocean Acidification (OA)
WRAC
Iria Gimenez,on behalf of Dr. George G. Waldbusser
Gulf States Marine Fisheries Commission"Gulf of Mexico Oysters, the Industry, and the Future“
October 13, 2016
What is Ocean Acidification (OA)?
NOAA (2016)
The balance of these two processes controls the C chemistry of the ocean:
1) CO2 emissions into the atmosphere and oceans2) Weathering of terrestrial sediments into the ocean that buffer the
addition of CO2
Now we are increasing CO2 emissions faster (10s of years) than weathering can keep up with (10,000 years)
The release of CO2 was 10x slower during our closest analog on the geological record (PETM) (Zeebe et al. 2016)
The increase of dissolved CO2 (PCO2) in the ocean has already decreased pH and saturation state (Ω)
Ω is a measure of how corrosive the water is for calcium carbonate (shells)
Ω = 1 : Thermodynamic stabilityPMEL (2016)
How does OA change the chemistry of the ocean?
Mauna Loa observatory; HOTS
~80% of bivalves studied to date show how negative responses to increasing CO2
Windows of vulnerability across and within life-stages
Carry-over effects across life stages
What does OA mean for shellfish?
PNW Pacific oysters: Canary in the Coal Mine
Whiskey Creek Shellfish Hatchery
(WCSH)
Starting in 2007, WCSH located in Netarts Bay, OR experienced Pacific Oyster larval production failures.
In 2009, Dr. Burke Hales (OSU) installed carbonate chemistry high-frequency monitoring equipment
Hourly, daily and weekly timescales of variability are physiologically relevant for larvae
Barton et al.(2015)
10s of cohorts of larvae raised in hatchery analyzed
50% of the variability in larval cohort hatchery production explained by ΩAr in first 48 hours
PNW Pacific oysters: A partnership between Industry and research
Barton et al. 2012
(first 48 hours)
Barton et al. (2012)
Ω controls early calcification on C. gigas larvae
C. gigas
Prop
ortio
n no
rmal
Shel
l leng
th (µ
m)
Waldbusser et al. 2015
Laboratory experiments identify Ω (not pH or PCO2) as the parameter controlling development and growth on early bivalve larvae
Pacific oysters: early larval stage very sensitive. Why?
Waldbusser et al. 2015
1. High rate of calcification2. Calcification “exposed”3. Limited energy
PDI Shell Formation (First 24-48 hours)10 Hrs.
14 Hrs.
16 Hrs.
What about the West Coast native oyster ?
O. lurida : no acute negative response to increasing PCO2 or decreasing Ωarand pH
Proportion Normal Shell Length
(µm)
Waldbusser et al. 2016
1. Slow calcification
2. High energy supply
3. Low energy consumption
PDI Shell (First 90-120 hours)
96 Hrs
108 Hrs
120 Hrs
Does this mean that native species are adapted?
Waldbusser et al. 2015
PNW native mussels show the same response to saturation state than the non native species.
What does OA mean for Eastern Oyster larvae?
Increased mortality, delayed development and reduced growth under increased PCO2
Delayed development and metamorphosis increase vulnerability to predation
~1,5
00 p
pm P
CO
2~6
60 p
pm P
CO
2~3
50 p
pm P
CO
2
%Su
rviv
al
Modified after Talmage and Gobler 2009
~350 ~660 ~1,500
PCO2 treatment (ppm)
Larv
ae le
ngth
(μm
)
No experimental data that includes exposure to OA during early shell development!
What does OA mean for Eastern Oyster larvae?
Modified after Talmage and Gobler 2012
~390 ppm PCO2
~850 ppm PCO2
Harmful Algal Blooms (HABs) are already prevalent in the Gulf of Mexico and are predicted to intensify
Exposure to OA and even low density HABs: Synergistic effects
Further reduced survival and delayed development
What does OA mean for Eastern Oyster juveniles?
Waldbusser et al. 2011
Juvenile calcification rate (proxy for growth) correlated with Ωca
Different sensitivity thresholds across life-stages
Potential for carry-over effects from early exposures, already demonstrated in other oyster species.
Gulf of Mexico and OA
Cai et al. 2011
Multiple drivers of coastal carbonate chemistry can interact and decouple the carbonate system:
• freshwater input
• nutrient run-off • upwelling
Carbonate chemistry in the GOM :
1. high Ωar in surface shallow waters2. seasonal low Ωar in coastal subsurface waters3. Projections of lower Ωar by the end of the century
Gulf of Mexico signaled as vulnerable to OA –Why?
Modified after Ekstrom et al. 2015
Local amplifiers of OA: Coastal eutrophication and large freshwater inputs
Social vulnerability: Great importance of shellfish industry for local economy
Global Ocean Acidification Network (GOA-ON) on 10/10/2016
Gulf of Mexico and OA – What next?
High temporal resolution data close to oyster recruitment areas are key to:
1. Understand environmental variability
2. Identify sensitivity thresholds
3. Improve forecast models
4. Design effective mitigation strategies if needed
Only 2 high frequency monitoring carbonate chemistry data in the Gulf of Mexico and limited research cruises
Gulf of Mexico and OA – Building resiliency
• Monitoring stations to assess carbonate chemistry conditions relevant to oyster larvae, juveniles and adults
• Conduct research in OA effects on C. virginica across life-stages (particular emphasis on windows of sensitivity
Kelly et al. 2011
• Support efforts to restoreand manage oyster reefs and seagrass beds
• Support actions to manage nutrient inputs into estuaries
• Partnerships with local, regional and state stakeholders to facilitate action
Conclusions
1) Higher CO2, and lower pH and Ω result from the addition of CO2 to the ocean faster than alkalinity
2) Ω matters most for rapidly developing bivalve embryos- native and non-native. Probably the case for Eastern oysters.
3) Slow PDI shell formation may be a trait for resiliency to acute OA stress (O. lurida) (Kinetics!)
4) Eastern oyster larvae show decreased survival and growth and delayed development with high CO2, exacerbated during HABs.
5) Eastern oyster juveniles calcification rates also higher with increasing Ω
6) GOM vulnerable to OA due to local amplifiers of OA, but more monitoring and research needed to avoid a “tipping point” scenario for the shellfish industry.
Methods: Decoupling carbonate variablesStripping DIC and adding different DIC:Total Alkalinity ratios
4x4 factorial design: 16 treatmentsIndependent: 4 PCO2 levels and 4 Aragonite saturation states (ΩAr)Pseudo-independent: pH
C. gigas
Waldbusser et al. 2015
M. galloprovincialis
C. gigas
Waldbusser et al. 2015
Results: Development to PDI
Saturation State explained more than 85% of the variance in shell development.
M. galloprovincialis
Prop
ortio
n no
rmal
Normal
Abnormal
Waldbusser et al. 2015
Results: Shell length of normally developed larvae M. galloprovincialis
Shel
l leng
th (µ
m)
C. gigas
Saturation State explained more than 80% of the variance in shell length of normally developed larvae.
Calcification Rates and Energy C. gigas vs O. lurida
Waldbusser et al. 2016
O. lurida calcification rate is > 7x slower than C. gigas during the PDI stage.
The TAG:ST ratio (~energy : structural lipids) declines 50x faster in C. gigas than O. lurida.
O. lurida
C. gigas
Waldbusser et al. 2013
Calcification “exposed”
