Determining the Productivity of Biogenic Opals using

Ultra Violet Spectroscopy

Joseph J. Paliotti, Caitlin Chasen, Dr Timothy Herbert Department of Geosciences, Brown University

• Diatoms are a major group of eukaryotic algae, and are one of the most common types of phytoplankton.

• Diatoms cells are contained inside a unique silicate cell wall. (Hydrated Silicon dioxide or SiO2• nH2O)

•Biogenic Silica (Opals) are useful for tracing past climate changes.

•Changes in oceans circulation.

•How the sea temperature has changed.

• The effects of pollution on animals that feed on the seafloor.

• Upwelling is an oceanographic phenomenon that involves wind driven motion of dense, cooler, and usually nutrient-rich water towards the ocean surface, replacing the warmer usually nutrient-depleted surface water.

· Ocean currents tend to follow Earth's major wind patterns, but with a difference: the Coriolis force deflects surface currents at an angle of about 45 degrees to the wind—to the right in the Northern Hemisphere, left in the Southern Hemisphere.

• (DSi) in the form of water soluble silica or silicon hydroxide can be measures by standard analysis.

• Decomposition and decay of diatoms leads to organic and inorganic sediment.

• The inorganic component can lead to a method of analyzing past marine environments (by coring of ocean floors or bay mud).

Diatom Laminae

Extracting the silica from the core samples long process using wet chemistry and maybe a little black magic.

Light Source

Rotating Segment Mirror

Monochromator

Detector

Sample Cell

Reference Cell

% BSi = (((Y*Dilution factor*NaOH volume in liters*60.1)/1000)/ Wt. mg)*100

Results

Waiting for time to run results on the UV-Spectrometer

Results of Baja Samples% Biogenic Opals

0

10

20

30

40

50

60

5 55 105 155 205 255

Core Depth (cm)

% B

ioge

nic

Opa

ls

• Results of samples taken off the coast of Peru.

Results

Reducing the Amount of CO2

Gas in the Atmosphere.

• Conimicutt Point, RI August 20, 2003. More than one million fish, primarily menhaden, were reported killed This was the result of an environmental condition called anoxia or hypoxia (low oxygen) is often caused, as it was in this case, by blooms of tiny marine plants.

Do you remember…

Acknowledgements

National Science Foundation GK-12

Karen Haberstroh Director of GK-12

Dr.Tim Herbert Dept of Geosciences

Caitlin Chasen Dept of Geosciences

I would like to thank the following People and organizations

Resources

• Ocean B iochemical Dynamics By Jorge L. Sarmineto and Nicholas Gruber Princeton University Press

• Earth’s Climates Past and Future By William F. Ruodiman; W.H.Freeman and Company

• “Could Diatoms Help Offset Global Warming: www. Sciencedaily.com/releases/2008/01/080123150516.htm

•Planktos, Inc “Seeds of Iron” to mitigate Climate Change www. tree hugger.com/files/2006/02/ planktos php

• High resolution geochemical record from lake Edward, Uganda Congo and the timing and causes of tropical African drought during the late Holocene By James M. Russell and Thomas C. Johnson; Quaternary Science Reviews 24 (2005) 1375-1389

•Silica production in Monterey Bay, California, Upwelling systems By Mark A Brzezinski, Dennis R. Phillips, Francisco P. Chavez , Gernot E. Friederich and Richard C.Dugdale