Emeritus
Kent A. Fanning
Emeritus, Professor
Chemical Oceanography
Ph.D., Graduate School of Oceanography, University of Rhode Island, 1973
Email: kaf@usf.edu
CV: View PDF
Organic Nutrient Laboratory Website
* Please Note: These professors are retired and are no longer accepting new students.
Research: Marine Nutrients
Marine nutrients like dissolved nitrate or silica are the focus of Dr. Fanning’s research
through the Oceanic Nutrient Laboratory. The main emphasis concerns inorganic nutrients
in upper ocean waters, where most oceanic photosynthesis occurs even though nutrient
concentrations are often very low. The challenge is to detect changes in those concentrations
as precisely as possible and then try to find explanations for the changes. Detailed
surface surveys are conducted with highly sensitive nutrient measurements in patches
of coastal surface waters labeled with tracers. Nutrient concentrations in these waters
are usually well down into the nanomolar range. Principal nutrients under investigation
are the nitrate, nitrite, and ammonium ions. Findings to date are that nitrate and
nitrite in these waters show only slight variations from the averages over an annual
cycle but that, in sharp contrast, ammonium ion concentrations can vary up to many-fold
times higher than what appears to be normal background levels. Causes for this vastly
different behavior of ammonium ion relative to the other main nitrogen-bearing inorganic
nutrients are poorly known. A major part of the fieldwork is to develop a high-sensitivity
nutrient sensor that will function in an autonomous underwater vehicle (AUV). The
sensor will permit the determination of the lateral shapes of patches of coastal water
with ammonium enrichments, among other things. The AUV will greatly help the search
for explanations.
The Oceanic Nutrient Laboratory also conducts research concerns research on temporal
trends in nutrient concentrations within permanently anoxic ocean waters. Multi-year
trends are being measured in the Cariaco Basin along the Venezuelan continental margin,
and those results are compared to nutrient data from the Black Sea and other anoxic
regions in the ocean. The objective of this work is to understand the pathways by
which anoxia can alter chemical processes in the sea.
* Please Note: These professors are retired and are no longer accepting new students.