FSU researcher leads team to study conditions for plant survival in ocean desert

West of St. Petersburg in the Gulf of Mexico is an area called the West Florida Shelf. It’s a marine desert, cut off from many of the elements that are essential for life.

But in this nutrient-deficient region, some forms of phytoplankton — microscopic plants that float through the water — are thriving and supporting other forms of life. But how?

Florida State University Associate Professor Angie Knapp and a team of researchers from around the country have received a $2.3 million grant from the National Science Foundation to investigate this oceanographic mystery. Knapp, part of the Department of Earth, Ocean and Atmospheric Science in the College of Arts and Sciences, will lead the project to examine how iron and nitrogen released from submarine groundwater discharge potentially serves as a fertilizer for phytoplankton in this area and beyond.

“Plant growth in the ocean plays an important role in regulating atmospheric carbon dioxide concentrations, which plays an important role in regulating climate,” Knapp said. “However, plant growth in the ocean is often limited by the availability of nitrogen; thus, we’re focusing on the processes that add and remove nitrogen to and from the ocean.”

Submarine groundwater discharge is a ubiquitous hydrological process characterized by the flow of fresh and brackish groundwater from land into the sea. It plays an important role in moving nutrients, trace elements and gases that are often used by phytoplankton throughout ocean waters.

In this project, researchers want to understand exactly how far these elements are moved through the sea and to what degree they are being used by phytoplankton.