A Scientific Investigation by Coral Bleaching A Scientific Investigation by Sherrie Engram Matthew Grambow Emily Jeng Adam Rynalski Johanna Said

Last Week (Protein Assay) We created a Protein Assay for determining the BSA (protein) Concentration from absorbance. We did this by using a linear regression on 5 different protein concentrations (2 trials each). The x-axis was protein concentration while the absorbance was the y-axis.

Our Data: BSA A1 A2 A Avg mg/ml 0.25 0.355 0.37 0.3625 0.5 0.683 0.66 0.25 0.355 0.37 0.3625 0.5 0.683 0.66 0.6715 0.75 0.908 0.966 0.937 1 1.233 1.238 1.2355 1.25 1.428 1.404 1.416

Calculations: From the regression we calculated the standard curve to be y=1.1388x+0.0587. From this equation we plugged in the average weight of the two polyp samples into y and found x to be .11398. We multiplied this number by 2, the number of ml of seawater that the polyps were homogenized in. We then divided this number by the average polyp weight. Our final answer was calculated to be 13.42mg protein/g wet weight.

Compared to other groups: 13.42mg protein/g wet weight Group#2: 15.069mg protein/g wet weight Group#3: 21.31mg protein/g wet weight Group#4: 4.4036mg protein/g wet weight Average: 13.5507mg protein/g wet weight Our group’s data was .1307mg protein/g wet weight above the average. This was .96% off of the average.

Last Week (Chlorophyll Extraction and Measurement) To find the amount of Chlorophyll we centrifuged a sample containing 1ml of polyp homogenate and 9ml of acetone for 5 minutes at high speed. After the sample had been centrifuged, we decanted the supernatant and measured the absorbance at 665, 647, and 630nm wavelengths. Here are the absorbance values: 665nm= .057 647nm= .040 630nm= .043 Using the equation, Ca=(11.85A665)-(1.54A647)-(0.08A630), we plugged in our absorbance values and discovered that the Ca=.61041. To find the total concentration of the chlorophyll we used the given formula: mg Chl a/m^3=(Caxv)/(Vxp), and found the Chlorophyll concentration to be 1.71678 mg/cubic meter.

Our Experiment Proposal Null Hypothesis: Temperature will have no effect on coral bleaching. Alternate Hypothesis: If the temperature of the seawater is raised, it will induce coral bleaching.

Experimental Design We plan to raise the temperature in the tank from 30°C to 33°C over three weeks. We will raise the temperature by 1°C each week. Every week, we will measure the zooxanthellae density by using a hemocytometer. Our control group will be kept at 30°C for the extent of the experiment. Both tanks will be kept in equivalent salinity and light conditions. Both coral samples will have equivalent masses.

Any Questions?