Posted by CSUMB REU student Melia Paguirigan:

This summer I participated in the California State University Monterey Bay Research Experience Undergraduate program, with Dr. Colleen Durkin as my mentor. Our project investigated the role of diatom community composition and morphology in aggregation. We collected whole seawater samples from Monterey Bay.

Then I used a roller table to make aggregates.

In the lab, we used microscopy techniques to quantify the community composition of the aggregates and the corresponding surface water.

 

The data was then used to identify if diatoms differentially aggregate and if morphology was driving differential aggregation. Throughout this process I was able to become familiar with over 20 diatom genera, using their shape and colony formation as identifiers.

(Note from Colleen: Melia estimates that she counted >21,000 individual diatom cells this summer!  She found significantly different phytoplankton compositions in aggregates compared to the total community in seawater, suggesting that some genera tend to be incorporated into aggregates more than others.  Melia plans to present this data at a conference later this year.)