1. Pacific Oyster Physiological Response to
Disease under Variable Environmental
Regimes
Emma Timmins-Schiffman, Elene Dorfmeier, Paul McElhany, Shallin Busch,
Steven Roberts & Carolyn Friedman
University of Washington
PCSGA 2010

2. Objective
 How do environmental stressors, such as ocean
acidification (OA) and elevated temperature, affect
oyster larvae survival and physiology when
challenged by disease?

3. Experimental Plan
How do environmental changes affect the host-pathogen relationship?
High
OA
Temp.
Host
Pathogen
Vibrio photo: Waldor & RayChaudhuri, 2000, Nature

4. Outline
 Ocean acidification
 Environmental stress and physiology
 Temperature and the C. gigas-V. tubiashii
relationship
 OA effects on C. gigas
 Current work: OA & V. tubiashii
Hi
OA
T

5. Outline
 Ocean acidification
 Environmental stress and physiology
 Temperature and the C. gigas-V. tubiashii
relationship
 OA effects on C. gigas
 Current work: OA & V. tubiashii
Hi
OA
T

6. Ocean Acidification
1000 ppm
Increased CO2 in atmosphere
380 ppm
Increased oceanic CO2 = lower oceanic pH

7. Environmental Stress
Growth Reproduction
Normal Environment
Immune response General metabolism
Environmental Stress Growth Reproduction
Immune response General metabolism
pH

8. Outline
 Ocean acidification
 Environmental stress and physiology
 Temperature and the C. gigas-V. tubiashii
relationship
 OA effects on C. gigas
 Current work: OA & V. tubiashii
Hi
OA
T

9. Temperature & V. tubiashii
 Two temperatures: 12oC & 25oC
 V. tubiashii challenge in both temperatures
 3 day trial
 Immune response genes:
 C-jun kinase
 NfkB
Up-regulate immune defenses:
-ROS
-inflammatory response

10. Temperature & V. tubiashii
= 12oC
= 25oC
*
=12oC + Vt
* =25oC + Vt
1 2 3

11. Temperature & V. tubiashii
Assay Development
n=4
n=4
n=3 n=4 n=2
n=3 n=2 n=2
12oC 25oC 12oC 25oC 12oC 25oC 12oC 25oC

12. Outline
 Ocean acidification
 Environmental stress and physiology
 Temperature and the C. gigas-V. tubiashii
relationship
 OA effects on C. gigas
 Current work: OA & V. tubiashii
Hi
OA
T

13. Effects of OA on Development
 Strip-spawned and pooled sperm and eggs
 Fertilized eggs in pCO2-equilibrated water
 380 ppm
 840 ppm
 Time to developmental stage at
 1 hour (2-cell)
 2 hours (>4-cell)
 5 hours (hatched)
 17 hours
 24 hours

14. Effects of OA on Development
Timeline of C. gigas Larval Development
Fertilization 2-cell
0h
Developmental Stage
4-cell
1h
hatching
2h
5h
Time Post-Fertilization
veliger
17h
24h

15. Effects of OA on Development
=380 ppm
=840 ppm
Proportion Eggs in Cleavage
*

16. Effects of OA on Development
=380 ppm
=840 ppm
Proportion Larvae Hatched
*

17. Effects of OA on Development
 A smaller proportion of larvae in elevated pCO2
develop at the “normal” rate
 Implications for physiological anomalies and
calcification
SEM Photo: Carla Stehr

18. Effects of OA on Development
 General stress response genes
 Cytochrome P450 oxidase (CytP450)
 Peroxiredoxin 6 (Prx6)
 Heat shock protein 70 (Hsp70)
1.0
0.8
Proportion Hatched
0.6
0.4
0.2
0.0
5 5 17 17 24 24
Time Post Fertilization (Hours)

19. Outline
 Ocean acidification
 Environmental stress and physiology
 Temperature and the C. gigas-V. tubiashii
relationship
 OA effects on C. gigas
 Current work: OA & V. tubiashii
Hi
OA
T

20. OA & V. tubiashii
 Study in progress in collaboration with NWFSC (P.
McElhany et al.)
 Planned 3 weeks: spawning through settlement
 4 pCO2 treatments
 280, 380, 750, 2000 ppm
 24-hour V. tubiashii exposure
 Data collection:
 Mortality
 Physiology (gene expression)
 Morphology & calcification
 Genotype-linked survival

21. = calcified
OA & V. tubiashii = partially
calcified
 Calcification at 48 hours post-fertilization = uncalcified

22. Conclusions
 Ocean acidification has significant effects on C.
gigas larval development.
 OA may inhibit and depress larval response to other
environmental stressors, including disease.
 Elevated temperatures, such as 25oC, have effects
on the host-pathogen interaction.

23. Acknowledgements
 Funding: Saltonstall-Kennedy Grant (NOAA),
NOAA Aquaculture Program student support
 University of Washington
 Moose O’Donnell
 Sam White
 Taylor Shellfish
Joth Davis
Ed Jones
Vicki Jones
 NOAA Northwest Fisheries Science Center
 Jason Miller
 Mike Maher
 Sarah Norberg