Investigating Biological Conditions
In-water fluorescence data
Deep waters tend to be richer in the nutrients that support plant growth. When transported to the surface by upwelling, these waters warm up and algal growth is stimulated. Rapid growth rates of phytoplankton — i.e., microscopic algae at the base of the food web — cause upwelled waters to be heavily populated by many forms of marine life.
The amount of chlorophyll in the water column is measured using a
fluorometer, which hits seawater with blue light, causing the chlorophyll
(a common plant pigment) within phytoplankton to glow red. The resulting red fluorescence
is used to quantify chlorophyll concentration. The graphs
at right show summer fluorescence
data through the water column at the
M1 and M2 moorings.
Satellites, such as NASA's SeaWiFS satellite, are also used to gather information about ocean primary production. Subtle changes in ocean color signify various kinds and quantities of phytoplankton. Thus, ocean color data can help determine whether upwelling occurred during the fall months.
Now that you're examined each piece of the puzzle, go to the fall data summary page to look for trends.