Graduation Year


Document Type




Degree Name

Master of Science (M.S.)

Degree Granting Department

Geography, Environment and Planning

Major Professor

Graham Tobin, Ph.D.

Committee Member

Kamal Alsharif, Ph.D.

Committee Member

Mark R. Hafen, Ph.D.


water quality, toxic dinoflagellates, water hyacinth, estuarine


The purpose of this study was to assess whether nutrient absorption rates by water hyacinths are affected by low-salinity levels. In a controlled experiment, water hyacinths demonstrated the ability to absorb a significant amount of nutrients in low-saline waters while maintaining a slowed growth rate and shortened life span. Nutrient rates were reduced by an average of 36% in ammonia nitrogen and 48% in reactive phosphorus in the tanks of 4.45 parts per thousand (ppt) salinity. Growth rate in the experimental tanks of 4.45 ppt was observed at 33% slower than that of the control. The high salinity comparison tank of 7.0 ppt experienced complete mortality after three days.

Phytoremediation practices through the use of an aquatic invader, water hyacinths, can be used to reduce large-scale fish kills along the eastern U.S.’s major estuarine systems, focusing on Florida’s waters. Toxic dinoflagellates and other harmful algal blooms have been plaguing the contributing waterways of North Carolina and the Chesapeake Bay and are the main causes of these massive fish kills. The characteristics and trends that these upstream estuarine systems are following could serve as a warning for Florida.

An analysis of Florida’s fish kill database, as well as patterns and trends of the fish kills in North Carolina and the Chesapeake Bay, were used to determine areas at an increased risk for toxic dinoflagellates and harmful algal blooms to occur. Areas are proposed for water hyacinths to be implemented in a controlled method to reduce massive fish kills in Florida’s waters.