Enviornmental Science Lab Report

EVR1001L

Lab 3: Ocean Acidification and Global Warming Lab

Materials and Methods:

This lab took place at the Kownlton Marine Research Station which us on a small island off the coast of Florida. The materials that were used were scuba diving gear and 5 identical tubes. Each tube contained corals of 2 types which were Acropora and Porites. Part of the lab was to observe the effects on sea water and corals in isolated environments when subjected to environmental changes. The way the environmental changes took place were they were controlled via the controls on the tubes which released seawater CO2 into the tubes and to regulate the water temperature. To change the temperature there was a dial that you pressed the arrows up or down. In order to complete this lab, I had to do 4 different readings. The first reading is an Fv.FM reading which is an underwater pulse amplitude modulated fluorimeter placed inside a tank. The second reading is a pH reading where a pH meter is placed inside a tube. The third reading is a bleaching percent reading where an underwater digital camera is placed inside a tank to take pictures of corals. The last reading is a calcite dissolution reading where a digital microscope is placed inside a tank. To determine a reading, I used a airlock tool for each tube one at a time to test the inside of the environment. This lab was a 6 months process because it took time for the water temperatures to regulate.

Results: Tables and Graphs:

Table 1 shows the data that was gathered from doing the experiment. It shows the order in which the experiment was conducted.

Table 2 shows the data that was gathered and organized from the experience. Table 2 is organized by temperature.

Figure 1 shows the data gathered for all pH and pCO2 data in the 6 months time range.

Figure 2 shows the data gathered of the percent bleaching data and the pCO2 data. It shows the 2 different corals at their 2 different temperatures.

Figure 3 shows the data gathered of the percent bleaching data and the pH data. It shows the different types of corals and at the 2 different temperatures.

Discussion and Conclusion:

There were 5 tubes used total. Tube #1 was the control tube. There were no changes to the environment inside the tube. The temperature of the tube was 25 degrees Celsius and the pCO2 was 400 ppm. For the Fv/FM reading the Acropora health was green and the Porites health was green too. The pH reading determined that the seawater had a pH of 8.05. The bleaching percent reading showed the Acropora and the Porites bleaching was at 0%. In tube #2 the environment temperature was raised by +3 degrees Celsius. There is no change to the C02 exposure. (400 ppm) Then I would observe the effects on the testing environment. Since it takes time for temperature change to take effect we fast-forwarded to 6 months’ real time. I then took all of the readings for the control and continued to do all the readings for the rest of the tubes. In tube #1 the control tube there were no changes they were the exact as when I last did the readings which were 6 months prior. Tube #2 now had a temperature of 28 degrees Celsius but still had a Co2 of 400 ppm because we didn’t change it. The Fv/Fm reading now showed yellow for the health of the Acropora and Porites. The pH reading showed that the seawater pH was at 8.05. The bleaching percent for Acropora bleaching had risen to 15% and the Porites bleaching had risen to 9%. The calcite dissolution reading had no change. For tube #3 we raised the Co2 to 750 ppm but left the temperature at 25 degrees Celsius. The Fv/Fm reading showed yellow for both the Acropora and Porites. The pH reading was 7.82. The bleaching percent reading was 7% for Acropora and 3% for Porites. And the calcite dissolution had a small change for both Acropora and Porites. For tube #4 we raised the temperature to 28 degrees Celsius and the CO2 to 750 ppm. The Fv/Fm reading showed both the Acropora and Porites health to be red. The pH reading was at 7.82. The bleaching percent reading showed Acropora to be at 29% and Porites to be at 22%. The calcite dissolution showed a small change for both. Tube #5 we left the temperature at 25 degrees Celsius but changed the Co2 to 1500 ppm. The Fv/Fm reading was red for Acropora and Porites. The pH reading was 7.55. The bleaching percent reading for Acropora was 30% and for Porites it was 20%. The calcite dissolution reading showed a large change for both. By increasing the pC02 it becomes more acidic because the pH is decreasing. Temperature does not make a difference because at both 25 and 28 degrees Celsius the pH decreased. pC02 does effect the percent bleaching. For Acropora the higher the pCO2 the higher % bleaching. As far as Porites goes the higher the pCO2 goes the higher % bleaching. There is a difference between Porites and Acropora. pC02 affects the extent of calcite dissolution because as I mentioned before the higher the pCO2 the more there is a change. As far as Acropora and Porites they are the same. As the pCO2 increases the same changes happen to both. pH affects the extent of calcite dissolutions because as the pH value decreases the calcite dissolution increases for both. Temperature and pCO2 have a synergistic relationship because the higher the pCO2 the more Acropora and Porites increase. The consequences for the coral ecosystem in a warmer CO2 enriched environment is the coral is the ability for of reef-building corals to produce skeletons is reduced because the C02 is increasing more than ever. If ocean acidification continues researchers fear that the corals would be disturbed and wouldn’t be able to recover. They could also erode faster than to be able to to rebuild which will hurt the coral reefs.

Figure 1

Y-Axis pH 400 750 1500 8.0500000000000007 7.8199999999999976 7.55

pCO2 (X-Axis)

pH (Y-Axis)

Figure 2

Acropora 25C 400 750 1500 0 7 30 Porites 25C 400 750 1500 0 3 20 Acropora 28C 400 750 15 29 Porites 28C 400 750 9 22

pCo2 (ppm)

% Bleach (Y-Axis)

Figure 3

Acropora 25C 8.0500000000000007 7.8199999999999976 7.55 0 7 39 Porites 25C 8.0500000000000007 7.8199999999999976 7.55 0 3 20 Acropora 28C 8.0500000000000007 7.8199999999999976 15 29 Porites 28C 8.0500000000000007 7.8199999999999976 9 22

pH

% Bleaching