Recently, we reached out to Hollis Jones, a recently graduated masters student from the Kelly Lab at LSU and current Knauss Fellow with NOAA SeaGrant to tell us more about her recently published article in Integrative and Comparative Biology. Her article is titled “Synergistic Effects of Temperature and Salinity on the Gene Expression and Physiology of Crassostrea virginica” and was published online on May 10, 2019.
What was the motivation to produce this work?
The Louisiana eastern oyster fishery provides 45% of the oysters consumed nationally (the largest contributor in the nation). Aside from their value as a fishery, the ecosystem services that they provide, such as shoreline stabilization, nursery habitat, and water filtration, have been valued at between $5,500 and $99,000/ha/year. River diversions and increased precipitation in the Southeastern United States has led to larger and longer pulses of freshwater in the northern Gulf of Mexico. This increased freshwater inflow combined with rising average temperatures in the Gulf of Mexico have had negative impacts on the eastern oyster across all life stages.
This study focused on the combined effects of heat and salinity stress on the eastern oyster, C. virginica, an ecologically, economically, and culturally important marine invertebrate inhabiting estuaries along the Gulf of Mexico. Our results suggest that timing and duration of freshwater events will have large impacts on eastern oyster recruitment and survival as temperatures gradually warm and push them closer to their tolerance thresholds.
What were some of the important or interesting discussions arose through and as a consequence of this work?
We can learn a lot about how an organism is dealing with stress by looking at what genes individuals express. Comparative transcriptomics allows us to compare gene expression profiles between treatments. In this study, we used a combination of comparative transcriptomics, physiological measurements, and field assessments to quantify the synergistic effects of combined temperature and salinity stress on adult C. virginica. Linking environment, physiology, and gene expression profiles provided a more complete picture of how climate change will impact these phenotypically plastic organisms. Temperature and salinity are only two of many shifting environmental variables and the cascading and sometimes unpredictable impacts of multiple stressors is why studies that measure responses to multiple variables will be key to predicting the effects of future environmental change.
What future directions do you hope to take in this area?
There is a need for the ability to assess oyster condition in the field after a stressful event like a hurricane or freshwater diversion. Our results suggests that the expression of select hypoosmotic stress genes could be used for this purpose. The ability to quickly classify oyster condition using gene expression profiles would be useful for monitoring efforts and potentially identifying resilient stocks that could be used for effective oyster reef restoration projects.
What did you most enjoy about producing this work?
I was born and raised on the Louisiana coast; researching an organism that simultaneously plays a critical role in the health of our coastal ecosystems and my Christmas dinner was amazing. Most everyone has heard of oysters, and most recollect them on the half shell (although our younger audience usually response with a definitive “yuck!”), but being able to relate oysters to hurricane resiliency or juvenile red snapper habitat is really rewarding.
Are there any other advantages to working with oysters?
One of the perks of working with oysters is that they’re delicious. When we were sampling oysters in the wild, gill tissue was excised and stored within minutes of dredging in order to minimize changes in gene expression associated with handling. After we take the tissue sample, we’re done with the oyster and they make a great snack! #sampleyoursample!
You can read the original article by Hollis R. Jones et al. here: https://doi.org/10.1093/icb/icz035