This 3 sentence summary provides the key points about using Pacific oysters to monitor Puget Sound ecosystem health:
Pacific oysters are proposed as useful indicators because they are widely distributed and sessile, accumulating contaminants based on their local environment. A study called PROPS is using biomarkers like gene expression, stress responses, and epigenetic changes in oysters from sites of varying pollution levels to evaluate the indirect biological effects of stressors and characterize impacts on shellfish. Preliminary results suggest noradrenaline responses and epigenetic variability can provide information on ecosystem health across oyster populations in Puget Sound.
9. PROPS: Physiological Response of Oysters in Puget Sound Objectives Implement use of biomarkers to assess Puget Sound ecosystem health Determine indirect biological effects of local stressors Characterize epigenetic impacts on shellfish
10. Methods: Site Selection Level of concern: High Mid Low Pacific oyster populations: natural set commercially farmed (outplanted juveniles)
13. Methods: Water Quality Data WA State Department of Health Department of Ecology University of Washington Salinity Mar-07 Jun-07 Sep-07 Dec-07 Mar-08 Jun-08 Sep-08 Dec-08 Mar-09
14. Methods: Integrated Approach Gene expression Indirect biological effects – response to a secondary stressor Epigenetic characterization
15. Gene expression Indirect biological effects – response to a secondary stressor Epigenetic characterization Methods: Integrated Approach
16. Indirect biological effects Are current environmental conditions impairing the ability of an organism to respond successfully to a future stress? Applying a stress in the field and evaluating response: stress (mechanical) response (noradrenaline) a “normal” response is an increase in noradrenaline after applying mechanical stress.
18. Gene expression Indirect biological effects – response to a secondary stressor Epigenetic characterization Methods: Integrated Approach
19. Epigenetics Heritable changes in trait or phenotype, caused by a mechanism other than mutation to the DNA sequence Most common epigenetic mechanism is DNA methylation: c c c c Me A G T C
20. Epigenetics Compounds that impact normal epigenetic functions: Endocrine disruptors estrogen BPA Effects of epigenetic disruptions: tumor promotion alteration of development inhibition of reproduction c c c c
21. Epigenetics: DNA methylation analysis Whole genome DNA methylation quanitification ELISA based Result is % methylated DNA Y Y extract DNA Y Y bind DNA to plate add antibody to 5-me-cytosine Y Y add secondary enzyme
23. Summary Noradrenaline concentration following stress may be a good candidate to evaluate indirect biological effects. Preliminary data show epigenetic variability between oyster populations in Puget Sound. These methods have the potential to provide valuable information on ecosystem health.
24. Acknowledgements Dr. Steven Roberts – UW, SAFS Samuel White – UW, SAFS Joth Davis - Taylor Shellfish Farms All the Volunteers
Hinweis der Redaktion
Today I’ll be talking about the research I’m doing at the university of Washington evaluating physiological responses of Pacific oysters to see what they’re telling us about ecosystem health
I’d like to start out by briefly explaining why Pacific oysters are good indicators of ecosystem health. Historically bivalves such as oysters have been used as bioindicator species because they meet 4 criteria of a good bioindicator.
This recognizable species can be leveraged as a tool to engage the public, and educate them about the threats to Puget Sound and what they can do to keep our beaches healthy
I’m going to be talking about a new project that I’ve been working on. And so I’ll introduce the project by giving a general overview, then spend some time discussing the methods that we are using to evalutate physiological responses in oysters – show preliminary data
(and assess associated effects on shellfish)
WA stateDepartment of ecology
At T=0, shell height of oyster line B was significantly larger than that of oyster line AAt 2 months, the oysters had grown between 77 and 161% of their height at T=0. There was no longer a significant difference between lines regarless of growing area. Growth between Willapa Bay and Samish bay was not sig different (~25mm), whereas oysters at North Bay were significantly larger than at WB and SM (~33mm), p=0.00.Survivorship at this stage is between 95 – 99%
Gene expression – what are is the organism responding to. Over time, a baseline will be generated and deviations from this can serve as early warnings of a change in stress level. Also specific genes can tell about what type of stress the animal is under for example detoxIndirect biological effect – this is an effect of a stressor or a mixture of stressors that may not be seen at a population level (menaing it is not lethal), but it could still have a sensitizing effect – making the organism less fit to handle a second stress – such as a pathogen exposure making it less likely to be able to respond quickly and effectively to that stressorFinally – epigenetic characterization. Epigenetics referes to hertible trait s not at DNA sequence. Many compounds effect epigenetic mechanisms such as DNA metylation. Many of things compounds are present in aquatic systems, including puget sound and it is important to understand effects this may have on organisms living there – if it is affecting oysters, it is probalby also affecting us.
Why are we interested in characterizing epigenetic profiles in oystersFirst of all – because it’s poorly understood. Most of the epigenetic work has been done in mammals and very little is known about epigenetic mechanisms in aquatic speciesAlso, there are compounds that disrupt normal epigenetic fxn – these have been detected in PSFrom studies done in mammals we know that disrupting epigenetic systems can have some very negative effects such as….Therefore, characterizing in oysters can tell us not only what is “normal” epigenetic profile for an oyster, but also what effects environmental conditions have on those profiles.
To study this we are doing whole genome DNA methylation quantification.
Further characterization will be required in order to evaluation what impact environmental conditions play in this variability.
I am excited and motivated about the opportunities in this project, and I would be very interested in getting thoughts input and ideas about any of the aspects of this project.I am excited about the project and encouraged by the data, because it appears that these methods have the potential to provide valuable information about ecosystem health – and the associated effects on shellfish. I would be very interested in comments and input regarding how to move forward with this project and make it even better.