Empfohlen
Empfohlen
Weitere ähnliche Inhalte
Andere mochten auch
Andere mochten auch (20)
Kürzlich hochgeladen
Kürzlich hochgeladen (20)
Low vs high CO2 gas sampling
- 8. LC – Low CO2 HC – High CO2
- 13. Sampling !!
- 14. X 3
Hinweis der Redaktion
- Hello, my name is Andrew, and today, I am here to talk about diatoms. Diatoms or Bacillariophyceae, are one of the major groups of phytoplankton. Perhaps their most distinctive feature is the glass cell wall made of silica
- They exhibit a size between 2 – 200 micrometers, and they reside in almost everywhere where water and sunlight reach. There are believed to be around 100.000 species of diatoms, and new diatoms species are still being discovered today.
- Although they are unicellular organisms, they can form colonies in the shapes of filaments or ribbons, stars. They were first discovered in 1783, and according to the fossil records, they originated around jurassic period.
- Scientists still are speculative about exactly when diatoms became abundant in ancient seas, but according to the fossil records, some believe that diatoms were one of the contributors which the oxygen levels around the globe drastically increased during that time.
- Diatoms still are one of the major contributors on carbon fixation. Almost about 20% of global photosynthesis fixation of carbon is being done by diatoms. Which is more that twice of all tropical rainforests combined on Earth.
- Since 1900s undergoing the first and second industrial revolutions, and other factors like deforestations, along with methane and nitrous oxide gas, Carbon dioxide levels increased dramatically. In less than 100 years, CO2 levels increased to 400ppm.
- At this point, you might wonder, wouldn’t more CO2 just means that there will be more diatoms and more food source for marine life?. Well, If I learned anything in science, is that too little or too much is never a good thing. In the study done by Gao et al, in 2012
- The rise of CO2 levels in the atmosphere and ocean and increased sunlight intensity actually have a negative effect on the growth rate of diatoms, as well as their carbon fixation capabilities. And they concluded that this may cause a widespread decline on diatom communities.
- Countless research have been done for the diatoms, but most of them are focused on either taxonomy or biochemistry part of it. This could be due to a technological advance including next generation sequencing or improved microscopy.
- An example of such technological advance abled scientists to create a genetically engineered diatom which is capable of target cancer cells in humans which could replace nanoporous silica-based materials which requires costly and toxic chemicals.
- But interactions in-between species or between the environments, either positive or negative are also an important aspect to look at. They could explain some of the behaviors of organisms where biochemistry alone cannot explain, such as correlations due to mutualism or competition.
- This is where I propose my research; To determine whether the diversity is also a contributing factor to individuals’ carbon fixation capabilities, To determine if the diversity itself has either positive or negative effect on diatom communities regarding their fixation rate.
- Since the focus of the research is on marine diatoms, 10 samples of seawater will be collected on the coastal regions of the Pacific ocean in BC, and if possible, another 10 samples from coastal regions of Atlantic ocean in Newfoundland will be collected for the experiment.
- There will be 3 seawater tanks in total for the experiment. 1 for pacific ocean sample, 1 for Atlantic, and 1 with a single species of diatom which is common to both parts of the ocean. All three tanks will be supplemented with nutrients which diatoms require for growth, also letting grow for about a month
- To measure their carbon fixation rate, initial CO2 levels underwater at the start time will be measured, turn off CO2 supply, and CO2 levels will be recorded hourly for 10 hours. The process will be done about 2 days apart for the communities to restore ideal conditions.
- Total of 10 observations will be done for statistical analysis to determine if there is a significance. I would expect there will be a significant difference of metabolism rate between diverse diatom communities, and single diatom community.
- Scientists expect that CO2 levels will continue to rise and pH will continue to decrease, where CO2 levels and pH are the determining factor for the growth and carbon fixation capabilities of diatoms. Because of their importance it is crucial to study the unknown aspects of diatoms to prepare the worst.
- Understanding the interactions around diatom communities might provide the importance of the diversity of organisms around the world, and also provide insight to the future solutions to global climate change which is happening right now.
- Diatoms’ contribution to the global carbon economy were not fully appreciated until 1999. Now we know the fate of the carbon that diatoms fix is now a crucial issue in climate change research. Almost all life on Earth are in the hands of these tiny micro-organisms.
- This concludes my presentation. Thank you for listening, and the take home message is: an algae is saving the world where a human destroys it like always.