As intertidal communities face predicted increases in temperature and hydrodynamic disturbances due to climate change, organisms may find it necessary to reallocate energy among normal physiological processes for survival. Specifically, mussels must distribute energy among processes such as attachment, shell growth, metabolism, and reproduction, all of which may be influenced by seasonality and other natural environmental fluctuations (temperature, pCO2, etc.). Examining energy distributions is the first step in predicting responses to environmental change. In the present study, we investigated the energetic cost of byssus production for the intertidal mussel Mytilus trossulus. After performing an initial pilot study to establish methods for manipulating byssus production by controlling how often the mussels had to replenish byssal threads (ie. daily, weekly, never), we exposed collected mussels to each treatment in triplicate for a four-week period. We then assessed the energetic cost associated with byssus production in relation to energy allocated to other processes such as growth and development. For all measures (length, width, height, shell mass, etc.), forcing the mussel to produce more byssus resulted in a decrease in growth rate; this was significant for length and shell mass. For this study, activities for making longer shells were first to be forfeited as mussels were manipulated into manufacturing greater amounts of byssus during a season where developing reproductive structures were of highest priority. This research identifies byssus production as a major energetic constraint in mussels, which play an important role both economically through aquaculture as well as in intertidal marine ecosystems. As these globally marketed shellfish are placing more amounts of energy towards byssus production, less energy is available for growth. Coupled with modeling predictions, this information could be useful for aquaculture practices as well as understanding physical changes mussels undergo in response predicted climate change.

Over the last four decades, marine community composition has changed in the San Juan Archipelago, showing a density decline in the scleractinian (hard skeleton) solitary cup coral Balanophyllia elegans. Determining predictors of B. elegans abundance, distribution, and size is important for ecological research in the eastern Pacific Ocean because changes observed over time could be an indication of realized impact from climate change and ocean acidification on calcifying organisms. Though reef corals are heavily studied, little is known about temperate, solitary corals. We studied B. elegans in the San Juan Islands in transect photos from 2008-2011 at 11 sites. At two of the sites, we analyzed photos to determine the distributions of size and abundance at 3-27 m depth. At all of the sites, we evaluated the effect of flow rate on coral size and population density by grouping the data from depths between 15-21m at the 11 sites into 4 categories of flow: low flow, medium flow, high flow, and very high flow. We used multiple statistical tests, including the Gaussian General Linear Model and the Poisson General Linear Model, with ANOVA to analyze the data. We found that the distributions of B. elegans vary by site, depth, and year. The results tell us that each site is unique. Even though some of these sites are separated by mere meters, characterized by the same flow rates, and evaluated on equivalent slopes, they appear to differ enough to create measurable variance. The patterns we found will need to be explained by researching these sites longer and adding additional site variables, such as pH. Fluctuations in pH, potentially caused by changes in rates of upwelling in the northern Pacific Ocean, could cause short term trends of increasing population size of calcifying organisms when pH is higher, but significantly reduced populations when pH is lowered by increased upwelling.

Vitamin D is an essential hormone in the body that helps regulate calcium and phosphate homeostasis. The effects of vitamin D in the body depend on dietary intake, sun exposure, and the ability of the body tissues to convert vitamin D into biologically inactive and active forms. One of the metabolic processes involves the sulfation of 25-hydroxyvitamin D₃ [25(OH)D₃], a form of the hormone that is a major circulating vitamin D metabolite in humans and can be excreted into the bile to affect the function of intestinal epithelial cells. In this research experience, I studied the relative efficiency of the 25(OH)D₃ sulfation reaction by liver sulfotransferase enzyme (SULT2A1) and the effects of the sulfate metabolite on intestinal epithelial cell gene expression. Using purified SULT2A1 and pooled human liver cytosol, I helped to determine the rate of the sulfation reaction over various 25(OH)D₃ concentrations. The Michaelis-Menten equation was used to determine kinetic parameters, which established the efficiency of 25(OH)D₃ sulfation. In order to determine which enzymes are regulated by 25(OH)D₃-sulfate, I tested the effects of 25(OH)D₃-sulfate on the expression of different gene targets in human intestinal cell systems. LS180 cells were used as a human cell model in order to examine how changes in concentration of phosphate solution and 25(OH)D₃-sulfate affect the enzyme gene expression in the cells. The experiments consisted of LS180 in various concentrations of phosphate and 25(OH)D₃-sulfate solutions. The cells were incubated, and lysed to isolate their RNA. Then, the RNA was converted into DNA to be retrieved via a PCR machine, which amplified the difference in relative mRNA expression among different enzymes. This study is expected to provide in vitro evidence that 25(OH)D₃–sulfate plays an important role in regulation of intestinal gene expression, which contributes to optimization of individualized drug therapies using vitamin D.