Jessica Soule - Nutrient Lab
Boston College, MA
Iron and Phosphorus interactions along the salinity gradient of the Patuxent River
In fresh water bodies, phosphorus has been shown to be the nutrient that limits primary production. Overloading of nutrients like P can cause have a negative impact on the aquatic environment. Understanding what form the P is taking in water bodies is critical to understanding how much P will be readily available for utilization versus how much will remain bound up in soil.
My project focused on whether P is bound to Fe(II) or Fe(III). Bacteria can utilize Fe(III) as a final electron acceptor in anaerobic conditions, reducing it to Fe(II). Any P that had been bound to Fe(III) is released upon the Fe(III) reduction. In saltier water, that reduced Fe(II) may become bound up in complexes with sulfides, and be unable to rebind to P. We therefore hypothesized that in saltier water there would be more unbound P in solution, and I was looking to see if there was any evidence of that. I also was interesting in whether Fe(II) could bind with P, or whether only Fe(III) was likely to bind P.
Funding provided by the National Science Foundation - REU