College
College of Marine Science
Mentor Information
Dr. Dreux Chappell
Description
Nitrogen is unusable by most organisms but is an essential nutrient for building life. Nitrogen fixers in the ocean, also known as diazotrophs, can produce bioavailable forms of nitrogen for other organisms to use from dissolved nitrogen gas. The West Florida Shelf is of particular interest for research on nitrogen fixers because it is generally oligotrophic, yet diazotrophic activity is hypothesized to increase regional productivity. Our understanding of the distributions of cyanobacterial nitrogen fixers is limited, and broadening this knowledge can inform other decisions and research on ocean health or productivity. This study advances understanding of the abundance of symbiotic cyanobacterial nitrogen-fixing plankton on the West Florida Shelf to demonstrate the locations of bioavailable nitrogen in the ocean. Using TaqMan Assays in qPCR, the nifH gene was targeted to quantify Het-2, UCYN-A1, and UCYN-A2. Het-2 was found in warmer waters inshore, with low N+N and high silicate levels, whereas UCYN-A1 and UCYN-A2 were found together in cooler waters. Both Het-2 and UCYN-A2 were positively correlated with higher salinities. These results have expanded a time series on the West Florida Shelf, providing more information on nitrogen-fixing symbionts.
Exploring abundance of symbiotic cyanobacteria nitrogen fixers on the West Florida Shelf
Nitrogen is unusable by most organisms but is an essential nutrient for building life. Nitrogen fixers in the ocean, also known as diazotrophs, can produce bioavailable forms of nitrogen for other organisms to use from dissolved nitrogen gas. The West Florida Shelf is of particular interest for research on nitrogen fixers because it is generally oligotrophic, yet diazotrophic activity is hypothesized to increase regional productivity. Our understanding of the distributions of cyanobacterial nitrogen fixers is limited, and broadening this knowledge can inform other decisions and research on ocean health or productivity. This study advances understanding of the abundance of symbiotic cyanobacterial nitrogen-fixing plankton on the West Florida Shelf to demonstrate the locations of bioavailable nitrogen in the ocean. Using TaqMan Assays in qPCR, the nifH gene was targeted to quantify Het-2, UCYN-A1, and UCYN-A2. Het-2 was found in warmer waters inshore, with low N+N and high silicate levels, whereas UCYN-A1 and UCYN-A2 were found together in cooler waters. Both Het-2 and UCYN-A2 were positively correlated with higher salinities. These results have expanded a time series on the West Florida Shelf, providing more information on nitrogen-fixing symbionts.
