Sieracki, C. K. Bigelow Laboratory for Ocean Sciences, CSieracki@bigelow.org
Sieracki, M. K. Bigelow Laboratory for Ocean Sciences, MSieracki@bigelow.org
RESULTS OF CONTINUOUS AND DISCRETE FLOWCAM MEASUREMENTS OF PLANKTON COMMUNITY STRUCTURE, BOOTHBAY HARBOR, MAINE, USA
The Bigelow Laboratory flow cytometer and microscope (FlowCAM) was used in the summer of 1998 to analyze marine microplankton in water from Boothbay Harbor, ME. Sampling was either with discrete samples of several ml or in continuous flow at 1ml per minute. Particles with chlorophyll or phycoerythrin fluorescence and between 10 and 1000 micrometers in size were analyzed and imaged. The presence of different plankton species of different size and fluorescence generates different signatures in the FlowCAM fluorescence vs. size scattergrams. These signatures may be analyzed interactively since they are dynamically linked to the original images used to generate the scattergram.
Discrete samples from different days show a progression of species over the summer from a dominance of Alexandrium sp. in mid June, to centric diatom chains in early August, to Prorocentrum micans and Dinophysis sp. in September. Continuous sampling over periods of several days shows the effect of tide, sunlight and rain on flagellates and diatom patches. The flood tide corresponded with higher cell densities, possibly because the current brought water from a plankton rich region past the sample area. Sunlight induced a diel variation of individual cell fluorescence. Diel vertical migration of Dinophysis was observed. August rains induced a bloom of diatoms in the harbor with a density of 10,000 chains per ml.
The FlowCAM can provide real-time, continuous monitoring of microplankton and will be useful as an early warning system for detecting harmful species in coastal waters.
Day: Wednesday, Feb. 3
Location: Sweeney Center