College
College of Marine Science
Mentor Information
Dreux Chappell
Description
Trichodesmium is a free-living, marine cyanobacterium that acts as a biological nitrogen fixer, capable of using typically unavailable dissolved nitrogen gas. It is responsible for producing up to half of the usable nitrogen that is necessary for the survival of marine organisms and environments. Researching the abundance of different nitrogen-fixing species allows for a greater understanding of the importance of nitrogen fixation in certain environments. Specifically on the West Florida Shelf (WFS), where nutrient levels are low, it is hypothesized that nitrogen fixers support a significant portion of primary productivity. This study used qPCR of the rnpB housekeeping gene to quantify the distribution of the 2 major clades of Trichodesmium (T. thiebautii and T. erythraeum) on the West Florida Shelf. T. thiebautii was found in higher abundances offshore compared to inshore. It was also found to be more abundant in lower salinity waters. T. erythraeum was found in higher abundances in warmer temperature waters compared to cooler temperature waters. Similar to T. thiebautii, T. erythraeum was found in lower salinity waters. This strengthens the previous findings of other research on the WFS and expands a time series investigating Trichodesmium abundances across the WFS.
Abundance of Free-Living Cyanobacterial Nitrogen Fixers on the West Florida Shelf
Trichodesmium is a free-living, marine cyanobacterium that acts as a biological nitrogen fixer, capable of using typically unavailable dissolved nitrogen gas. It is responsible for producing up to half of the usable nitrogen that is necessary for the survival of marine organisms and environments. Researching the abundance of different nitrogen-fixing species allows for a greater understanding of the importance of nitrogen fixation in certain environments. Specifically on the West Florida Shelf (WFS), where nutrient levels are low, it is hypothesized that nitrogen fixers support a significant portion of primary productivity. This study used qPCR of the rnpB housekeeping gene to quantify the distribution of the 2 major clades of Trichodesmium (T. thiebautii and T. erythraeum) on the West Florida Shelf. T. thiebautii was found in higher abundances offshore compared to inshore. It was also found to be more abundant in lower salinity waters. T. erythraeum was found in higher abundances in warmer temperature waters compared to cooler temperature waters. Similar to T. thiebautii, T. erythraeum was found in lower salinity waters. This strengthens the previous findings of other research on the WFS and expands a time series investigating Trichodesmium abundances across the WFS.
