Student Scholar Symposium Abstracts and Posters

Document Type


Publication Date

Spring 5-14-2015

Faculty Advisor(s)

Hesham El-Askary


Trichodesmium, a genus of diazotrophic bacteria, has the capability and the population to produce a large percentage of the total oceanic N2-fixation. Though their population is known to be heavily dependent on two of the ocean’s largest limiting factors, phosphorus and iron concentrations, it is unknown what affect these factors have on the population. In this study two of the largest colony formations of Trichodesmium in the North Atlantic, tufts and puffs, are compared nutrient quality with respect to time and geographical location. Though very little nutrient in situ data was collected from the cruise, remote sensing data collected from the MODIS satellite was used to bolster information dealing with nutrient quality. High tuft concentration was observed within the center of the North Atlantic Gyre, where puff concentrations were not collected until below the 26⁰ N latitude line (in the South Sargasso Sea).

In turn, puff concentrations were recorded to spike when iron concentrations along the cruise track were higher. Tuft concentrations were observed at low and high iron concentrations. By comparing Trichodesmium colony orientation and concentration to general remote sensing of nutrient quality, correlations and suggestions could be reached.


Presented at the Spring 2015 Student Research Day at Chapman University.