Research

Transgenerational responses to pH in the copepod Tigriopus californicus 

tigriopus_liguoriTigriopus californicus is a model copepod that is well-studied in terms of its ecology and stress tolerance but surprisingly, few studies have investigated its responses to pH. In its high intertidal habitat, where pools are like small isolated mesocosms, pH can be extreme and variable (as low as 6 to above 9 pH units). Respiration, photosynthesis, and many other factors drive the pH dynamics that these animals experience.

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Water samples during spectrophotometric pH analysis- from the top down: pH of ~ 7, 7.5, and 8.

I am investigating how different pH treatments affect the life history and morphology of T. californicus across multiple generations, and whether previous pH exposure influences performance in current conditions. Since populations of these copepods are often highly genetically differentiated, even at small geographic scales, I am comparing responses among four populations to test the generality of responses to pH in T. californicus.

I have completed long-term experiments in the Ocean Acidification Environmental Laboratory at Friday Harbor Laboratories, where I maintained target seawater pH treatments by adjusting quantities of dissolved carbon dioxide gas, mimicking how pH changes in Tigriopus pools in the field.


Testing for local adaptation to salinity and temperature variability

I am exploring the potential for local adaptation to microhabitats with different amplitudes of abiotic variability in T. californicus. Understanding the evolution of plasticity to such variation will be critical for predicting the population dynamics of Tigriopus and other coastal organisms that can experience environmental variability, which will likely become more extreme with continued climate change.

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Measuring salinity in a Tigriopus pool.

In previous research, I found that T. californicus populations on San Juan Island in Washington have distinct morphology, stress responses, and life history characteristics. I am working to determine if these differences are due to genetic differentiation and local adaptation, and testing whether populations have evolved different capacities for coping with the combined stressors of high salinity and temperature variability. I am characterizing population performance under a range of abiotic conditions in common garden laboratory experiments, and monitoring environmental conditions (potential selective pressures) in the field at each population site.


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Study sites on San Juan Island, WA.

 

Population genomics of Tigriopus californicus on San Juan Island, WA

As part of a NSF GRIP internship at the NOAA Northwest Fisheries Science Center with Dr. Krista Nichols, I am using RAD-seq and Pool-seq methods to characterize genomic differentiation among the T. californicus study populations from my dissertation research.

 


Adaptation and acclimation to ocean acidification in Mytilus edulis

I am part of a Sea Grant-funded, collaborative project with the Padilla Laboratory (Stony Brook University) and the NOAA Northeast Fisheries Science Center at Milford, CT, investigating resilience to ocean acidification (OA) in populations of blue mussels across a water quality gradient in the Long Island Sound. We are conducting multigenerational experiments to test whether the mussels can acclimate and/or adapt to OA, and to explore whether populations from different environments are locally adapted and possibly pre-adapted for tolerance to future OA.