Title:

Application of a continuous imaging flow cytometer for monitoring estuarine microplankton.

PIs:

Michael Sieracki
Christian Sieracki
Bigelow Laboratory for Ocean Sciences, W. Boothbay Harbor, ME
FlowCAM Web Site

Status:

The Wells FlowCAM project is on schedule and the development of the actual instrument is going as proposed. The design and construction phase of an instrument suited to the Wells Site is well underway. All major components have been purchased and we are in the process of integrating them. We have made several site visits to discuss the instrument with the Wells NERR personnel and the Wells Harbor Master, and to measure the physical configuration of the site where we shall install the instrument in March 2000. Scott Orringer has been trained here at Bigelow and will take on the oversight of the instrument operation and routine maintenance at the Wells NERR.

Figure 1. Plan view of Wells Harbor Pier site. The FlowCAM instrument will be installed on the floating dock with a 180 ft. cable connecting to the computer and wireless internet connection in the Harbor Master office.

 

 

Figure 2. Tidal study of the Wells Harbor Pier site. The best arrangement for the cable to handle the tidal variation is for it to follow the footramp to the floating dock.

 

 

 Figure 3. Instrument layout showing compact design for housing optics, fluidics, and ancillary sensors (Meters).

 

 

 

Because Wells is a high pedestrian traffic area, we have given special consideration to designing the instrument housing and cabling to be out of the way and not attract too much attention. Construction of the housing is underway

While the design is underway, other construction is taking place. The imaging and fluorescence monitoring optics are built and will be installed into the housing when it is complete. The software, electronics and industrial computer have been integrated and tested with good results. The Wells site has been examined by a wireless internet vendor who determined that the site is acceptable and has delivered the required equipment.

We have developed several methods of data display for remote monitoring of instrument performance (Figure 4). Since we are planning to monitor both fluorescent and non-fluorescent suspended particles, the latest software switches between the two triggering modes every half-hour. as can be seen at the Bigelow Labs for Ocean Sciences FlowCAM website ( http://flowcam.bigelow.org/ )

Figure 4. Real-time data display to monitor instrument performance.

The top plot shows the chlorophyll fluorescence versus size for the whole run. The middle graph shows the size of each particle

versus the total time of the run (up to several days). Each dot represents a detected cell. Any cells that the FlowCAM pattern-matching algorithm matches to a target organism are highlighted by a small cross. Presently, the target organism is an aloricate ciliate (Laboea sp.)

The bottom plot shows the position of each detected cell in the field of view versus the run time. Any fouling of the imaging chamber in the FlowCAM shows up as streaks on this graph. All graphs are updated every half-hour. The FlowCAM is currently switching between counting fluorescent particles and counting all particles. This switch takes place at the half-hour. This causes cyclical patterns in the temporal plots such as size vs. time. This switching allows the measurement of both total particles and fluorescent particles and will help to determine changes in suspended particles during dredging and help to illustrate the effect of dredging on phytoplankton.

February will see the integration of the different components and the testing of the instrument. At present, we are right on schedule with the original timeline and see no obstacles to our planned March installation.