Dominique Argote EVR1001L Global Warming and Ocean Acidification EVR1001L Introduction to Environmental Science Laboratory Introduction Anthropogenic climate change is primarily driven by human activities that increase the concentration of greenhouse gases in the atmosphere The main gases responsible for global warming include carbon dioxide CO methane nitrous oxide and fluorinated gases These gases trap heat in the atmosphere by absorbing infrared radiation creating a greenhouse effect that warms the Earth s surface The burning of fossil fuels deforestation and industrial activities are major sources of CO while agriculture and waste management contribute significantly to methane and nitrous oxide emissions Global warming also has a direct impact on ocean chemistry particularly through the process of ocean acidification As atmospheric CO levels rise a significant portion of this gas is absorbed by the oceans where it reacts with water to form carbonic acid This acid dissociates into hydrogen ions and bicarbonate ions increasing the acidity of seawater which can disrupt marine ecosystems particularly organisms that rely on calcium carbonate to build shells and skeletons Materials and Methods This research study took place at the Kownlton Marine Research Station located on a small island off the east coast of Florida and began with grabbing scuba gear and specialist equipment There were 5 identical tubes containing coral and 2 different types were to be measured The two species investigated in this lab were acropora intermedia nobilis and porites lobata During the lab experiment the tubes were exposed to atmospheric CO and temperature variations to assess the effects on water and coral health Tube 1 served as the control with no changes made to CO exposure water temperature or other conditions Initial measurements were taken from this tube using the Underwater Pulse Amplitude Modulated Fluorometer Fv Fm which provided an indication of coral health green healthy yellow stressed red unhealthy or dead The Underwater pH Meter was then used to measure the acidity of the water and the Underwater Digital Camera captured visual data Additionally the Underwater Digital Microscope was employed to observe the dissolution of calcite in the corals Tube 2 s temperature was increased by 3 C while CO exposure remained unchanged In Tube 3 CO levels were raised by 750 ppm with temperature staying the same Tube 4 experienced both a 3 C temperature increase and a 750 ppm rise in CO exposure Finally in Tube 5 CO exposure was elevated to 1500 ppm After six months the data from each tube were analyzed and compared to the initial control readings Dominique Argote EVR1001L Results Table 1 Measurements taken during observations including the changes in temperature CO2 concentration pH level Fv Fm measurements bleaching percentage and calcite dissolution for both Acropora and Porites Graph 1 A measure of how pH balance changes as CO2 concentration increases Graph 2 Bleaching of pCO for Acropora and Porites at 25 and 28 Graph 3 Bleaching of pH for Acropora and Porites at 25 and 28 Dominique Argote EVR1001L Discussion Graph 1 shows that as pCO levels go up the pH level goes down meaning the water becomes more acidic This happens because more pCO in the water creates carbonic acid which lowers the pH The increase in acidity can put stress on marine life that needs a stable pH to survive The graph also suggests that higher temperatures make this effect even stronger as the pH drops more quickly when both pCO and temperature are high Graph 2 shows that as pCO levels rise bleaching increases in both pCO is stressful for them bleaching than Porites at the same pCO levels This suggests that acidification than Porites possibly because of differences in how they respond to environmental stress Acropora however seems to be more affected with a higher percentage of Acropora might be less able to handle Acropora and Porites meaning higher Graph 3 shows that lower pH more acidic water leads to more bleaching in both Acropora and Porites Like with high pCO Acropora is more affected showing more bleaching than Porites at the same low pH This suggests that Acropora may be less able to handle acidic conditions which could put its survival at risk as the ocean becomes more acidic This trend highlights how sensitive corals are to acidic environments which can weaken their health and resilience Acropora and Porites Table 1 shows that as pCO levels go up calcite dissolution also increases for both However Acropora has more calcite dissolving than Porites at higher pCO levels This could mean that Acropora has a weaker structure or is less able to handle acidic conditions causing its skeleton to break down faster Such breakdown at high pCO can slow down coral growth and weaken the reef structure Dominique Argote EVR1001L Table 1 shows that as pH decreases making the water more acidic calcite dissolution increases for both Acropora and Porites In more acidic water the coral skeletons dissolve faster Acropora is affected more than Porites which could be due to differences in their skeleton structure or their ability to resist acidic conditions At the same pCO and pH levels higher temperatures increase both bleaching and calcite dissolution In samples with both high pCO and raised temperatures bleaching and dissolution are much higher Acropora shows more bleaching than Porites under these conditions suggesting it s less tolerant to heat Higher temperatures also speed up calcite dissolution in both types but Acropora is affected more Rising temperatures and decreasing pH have serious effects on coral ecosystems and human society First there s a risk of losing biodiversity as coral reefs are home to many marine species Acidification and warming lead to coral bleaching which can cause reef ecosystems to break down Second this affects fisheries since many fish depend on reefs for food and shelter which could impact food supplies and local economies Third coral related tourism could decline especially in tropical areas where reefs attract many visitors hurting those local economies Finally coral reefs naturally protect coastlines from storms and erosion so their decline makes coastal areas more vulnerable to damage putting communities and buildings at risk