Coastal Observations: a Biological Perspective

Research Cruises

Instrumentation used and performed by the High School and University Students:

A standard laboratory microscope is used to observe live water samples and determine which types of phytoplankton are present, by observing the size, shape, coloring, and structures associated with various species.

Epifluorescence Microscopy
An epifluorescence microscope is a microscope that only looks at light of a certain color that is emitted by phytoplankton cells. A beam of colored light is used to excite the cells and the microscope only looks for light that a specific type of phytoplankton will give off. Also, phytoplankton cells can be marked with a stain that will light up different parts of the cell when a beam of colored light is used to excite them. These two techniques provide more ways of identifying the different species in a phytoplankton sample.

Turner 10-AU fluorometer
The Turner model 10-AU fluorometer can measure the concentration of chlorophyll in samples that have been filtered down and extracted in acetone. The fluorometer uses blue light to excite the chlorophyll molecules and causes them to emit red light, which is then measured by the insturment. From this measurement of chlorophyll, a rough estimate can be made of the total amount of photosynthesis that could be performed by the phytoplankton in the sample.

The Perkin-Elmer LS50B spectrofluorometer is an instrument that scans through all the possible wavelengths of visible light for stimulating fluorescence in a sample and then measures the resulting intensity of the emitted light for each wavelength. This instrument is useful for determining, not only how much chlorophyll is in a sample, but also the amount of other pigments in the phytoplankton cells which absorb light. This information can then be used to determine the different types of phytoplankton cells in the sample.

Student Research Cruises