Thursday, October 14, 2010

CSB #2: Algae Power!

Right: Chisti with a photobioreactor
Definitions:
Photobioreactor: A production system in which all elements are controlled. In effect, there is no influence from the external environment other than light.
Nitrogen-fixing Algae: Algae which performs nitrogen fixation, a process which causes free nitrogen in the air to react with other elements to create more reactive substances, such as ammonia.

Summary:
Yusif Chisti of Massey University, New Zealand, believes that algae is the way to go in our world, where a new, clean, renewable energy source is desperately needed. However, contrary to many of today's experiments, which use freshwater algae, Chisti supports the use of marine algae for two reasons: first, it uses less freshwater, of which we have precious little, and second, it is easier to cultivate marine algae strains. Also, the marine strains can use waste carbon dioxide in its growing process and overall need a less complex habitat. One major problem is cultivating enough algae without using an equal amount of fossil fuels and an overlarge amount of fertilizer. As Chisti says, the way in which the algae is grown significantly affects its oil content. However, at this point, it needs too much energy to be a practical solution. Scientists are exploring nitrogen-fixing algae, and a possible solution for the energy requirement is a photobioreactor, which is more efficient than the current "grow it in a pond" method. Before algae can become a reliable energy source, though, much work is needed.

Discussion:
I agree with Professor Chisti that the way in which algae is grown can greatly affect its lipid content. I have done a lot of research on algae because it was part of my science project last year, and I was interested in this article because of that. Although energy efficiency is still a problem, it is true that algae would be a relatively simple change from fossil fuels, but it burns cleanly and is renewable. It is interesting that freshwater algae require more care as compared to marine strains, although this may be because marine algae is more used to changes in temperature and pH. This is because freshwater algae grows in sheltered ponds, into which there is no flow of water. I was not aware before that fertilizer usage as well as energy usage is a problem, but it is true that fertilizer is a somewhat exhaustible resource, so it would be good to reduce dependency on and usage of it.

Questions:
1) Why would nitrogen-fixing algae be more energy efficient than the average marine strain?
2) What methods of cultivation maximize lipid production?

Sources:
Nitrogen fixation:
"Nitrogen Fixation." Encyclopædia Britannica Online. Encyclopædia Britannica,
n.d. Web. 14 Oct. 2010. .
Article citation:
Extance, Andy. "Marine Algae Offer Sustainable Fuel Hope." environmental
research web. IOP, 13 Oct. 2010. Web. 14 Oct. 2010.
Article URL:
http://environmentalresearchweb.org/cws/article/news/44012

Wednesday, September 15, 2010

CSB #1: The Other Carbon Dioxide Problem

Definitions:
• Ocean Acidification: The process through which the ocean becomes more acidic because of the reaction between carbon dioxide and water, which creates carbonic acid.
• Copepod: A copepod is a small crustacean found in almost every freshwater system and many saltwater systems. They are food for salmon.
• Paleontology: The study of organisms from the distant past, based in geology, i.e. the study of fossilized bones or imprints of plants in layers of sediment.

Summary:
The ocean is undergoing a process of acidification because the CO2 in the air is reacting with the ocean water and creating carbonic acid. The ocean is taking in about 1/3 of total CO2 emissions, decreasing global warming, but it comes at a high price. Many of the ocean's animals cannot survive the rapid changes in pH that the ocean is undergoing, and reproduction rates are being harmed, possibly resulting in extinction. Experiments performed on copepods, snails, sea urchins, and brittlestar show that the struggle to match changing pH inside the organisms' bodies diminishes their capacity to grow and to reproduce. Below: a copepod.
Because the pH change is occurring so quickly, with a 30% increase in acidity since the industrial revolution, many species will not be able to adapt quickly enough and may not survive. Extinction of marine species would disrupt marine food chains, and this disruption would eventually reach humans. Action must be taken to decrease carbon emission levels, not only for global warming, but to decrease ocean acidification as well.

Discussion:
Disruption of the marine food chains could hurt humans in many ways. Certain species of copepods are food for salmon and other common eating fish. Extinction of salmon would severely hurt the economy through ending salmon companies and would hurt the human population, since food levels would go down. Unfortunately, salmon is not alone; oyster farmers are also having difficulty finding enough young oysters to stay in business. Additionally, the ocean is taking in less CO2 as it becomes saturated, meaning that the rate of global warming will increase. Some consequences of global warming are worldwide flooding, loss of many species, and enlarging the hole in the ozone layer, exposing the earth to harmful radiation. Clearly, ocean acidification and human wellbeing are interlocked, and I think that people need to pay more attention to this problem.

Questions:
1) Why does increase in pH cause the parts of the reproduction system to slow?
2) How long, on average, do most smaller marine animals take to adapt to changes in their environment?
3) Would slowing the process of acidification prevent losing some species?

Resources:

Hardt, Marah J., and Carl Safina. "Threatening Ocean Life from the Inside Out." Scientific American 
     Aug. 2010: 66-73. Scientific Research Center. Web. 15 Sept. 2010. 
     ehost/
detail?vid=3&hid=104&sid=06b4381b-afb4-4b29-a9a9-86ca74570f32%40sessionmgr111&bdata=JnNpdGU9ZWhvc3Qtb 
     Gl2ZQ%3d%3d#db=sch&AN=52112093>. 

"Hudson County Mosquito Control." Hudson Regional Health Commission. N.p., n.d. Web. 15 Sept. 2010. 
     . CITING IMAGE OF COPEPOD.