Diatoms plays a large role in oceanography. Due to the shell they have, Diatoms, once they die, become part of the sediment, leaving their silicate shell(Si02) behind. This is appropriately named diatomic earth. Over time, the sediment will weather out, providing more silica to the ocean. They are omnipresent, as they are marine floaters. They also provide how the condition of the water is and is used as a gauging tool for environments in the past, determining if there was any sort of pollution. They usually set a good record as they started to appear in the Cretaceous period. There are three types of diatoms, for three different types of diatoms based on nutrient limit toleration and water speed, the categories being low profile guild, medium profile guild and high profile guild. The diatoms in the low profile guild tend to be in nutrient-poor and live in high speed habitats. High profile guilds tend to live in nutrient high areas along with places with slow running water. This could be called their ideal spot. Last but not least, the medium profile guild would live in areas of moderate nutrients and moderate water speed.


Passy, Sophia I. "Diatom ecological guilds display distinct and predictable behavior along nutrient and disturbance gradients in running waters." Aquatic Botany 86.2 (2007): 171-178. Academic Search Premier. EBSCO. Web. 29 Apr. 2011.

D. B. Lazarus, B. Kotrc, G. Wulf, and D. N. Schmidt. Radiolarians decreased silicification as an evolutionary response to reduced Cenozoic ocean silica availability. PNAS, June 9, 2009; 106(23): 9333 - 9338.

Ecosystem Information

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Our zone covers from 200m to 1000m down in the Ocean, is largely deprived of light and is therefore home to many interesting creatures and organisms inhabiting the so-called twilight and midnight zones.

Due to the harsh conditions described by Smart, most believed not many, if any organisms could live in harsh conditions. Nonetheless, it led to the evolution of bio-luminescent creatures such as the angler fish, species with large eyes to see any possible light such as the giant squid and dependence on detritus as food or if size allows, a temporary place of shelter.

Organism Information

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Norwich GL111 Term Project Introductions

As part of our Introduction to Oceanography class this Spring 2011 semester at Norwich University, our group will be researching and presenting on plants and animals that live in an ecosystem called the 'Mesopelagic and Bathypelagic Open Ocean'.

We have three group members:
Nick Smart, Kyle Kickey, and Alex Chen

Each member of our group will be reporting on a different marine organism that lives in the mesopelagic or bathypelagic ecosystem zones of the open ocean. One will be a zooplankton, one a phytoplankton, one a marine invertebrate, and one a marine vertebrate.

As part of an integrated approach, we will be researching how our organisms interact with the other aspects of the ocean system (geological, physical, and chemical).