The Experiment<\/h2>\n
I grew phytoplankton in moderate sunlight and temperature conditions.\u00a0 They grew in plastic test tubes loosely covered to allow ventilation.\u00a0 Each tube contained an “f\/2 medium” beneficial to growth.\u00a0 This contained distilled water, “Instant Ocean” Sea Salt, a vitamin solution, trace metals, and other compounds to mimic ocean conditions.<\/p>\n
Acidic samples were made using Tris Hydrochloride and its conjugate base Tris.\u00a0 In the first week I grew samples at pH 7.7, pH 7.9, and the control ocean pH of 8.1.\u00a0 The second week tested the acidic condition at pH 7.5 compared to control ocean conditions. Every few days I took a visual reading of the phytoplankton’s color using a color-scale, or gradient of colors.\u00a0 This allowed me to record the number of phytoplankton cells.\u00a0 This was because our lab used an automated cell counter to measure what number of phytoplankton each color on the scale matched to.<\/p>\n
![\"\"](\"http:\/\/sites.sandiego.edu\/sdpollutiontrackers\/files\/2021\/05\/Picture2-300x161.png\")
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Figure 1:<\/u> The bottom color gradient was used to quantify the number of phytoplankton present throughout the growing period.\u00a0 Color scale from: Abualhaija, Rana et al. \u201cThe fifth shade of green: A novel approach to phytoplankton color index assessment in an oligotrophic system.\u201d Association for the Sciences of Limnology and Oceanography.\u00a0 18 March, 2020. p. 498.<\/em><\/p>\n The first batch was grown for 16 days and the second batch for 10 days.\u00a0 The results were then graphed as number of cells versus time.\u00a0 Error in the color-scale measurement technique was estimated at plus or minus 5 points on the scale or 30,000 cells.\u00a0 The error in measurement time of day was estimated as plus or minus four hours.\u00a0 When graphed, no statistically significant difference was observed between growth at more acidic pH of 7.5, 7.7, or 7.9 when compared to the control growth.<\/p>\n Figure 4 above shows how no difference\u00a0 between pH 7.7, pH 7.9, and the control pH 8.1\u00a0 No difference was observed between pH 7.5 and the control in batch 2 after 10 days (fig. 5).\u00a0 This suggests T. weiss\u00a0<\/em>growth is not hindered by ocean acidification. Acidity increases that could arise in the oceans over the next century do not appear to inhibit T. weiss’ <\/em>growth.\u00a0 A possible explanation is that these smaller diatoms rely less on the silica process than large diatoms.\u00a0 This supports the idea that smaller diatoms which are less reliant upon silica may be less harmed by acidification compared to larger diatoms.\u00a0 High future carbon dioxide levels in the atmosphere therefore may not harm T. weiss\u00a0<\/em>as much as large diatoms and other phytoplankton species.<\/p>\n","protected":false},"excerpt":{"rendered":" As Americans we drive in cars.\u00a0 We use electricity for our houses and cell phones.\u00a0 And we burn fossil fuels to power these processes. The average American releases more carbon into the atmosphere per capita than any other country in Continue reading Results<\/h3>\n
Batch 1 Graph: pH 7.5 and pH 7.9 vs. time<\/h5>\n
![\"\"](\"http:\/\/sites.sandiego.edu\/sdpollutiontrackers\/files\/2021\/05\/Picture3-300x166.png\")
<\/p>\nBatch 2 Graph: pH 7.5 vs. time<\/h5>\n
![\"\"](\"http:\/\/sites.sandiego.edu\/sdpollutiontrackers\/files\/2021\/05\/Picture4-300x190.png\")
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