Microbial Intrusions in the Mediterranean Sea

Microbial organisms such as phytoplankton performing photosynthesis generate most of the ocean’s organic carbon, but little is understood about how this carbon is transported to the deep dark sea ecosystems below. 

In collaboration with Woods Hole Oceanographic Institution and Marine Biological Laboratory, Assistant Professor Mara Freilich and her team at Brown investigated the role of eddies in connecting the ocean surface to deep ocean ecosystems. Other collaborators include researchers at IMEDEA (Spain), UCSD, and University of Washington.

The researchers followed the trajectories of water masses and sampled microbial communities along those trajectories. The project included trips on sea vessels where samples were collected at different depths in the ocean, which were then examined in the lab. They found that the communities were largely preserved as they moved to the interior ocean, but began to evolve as they are exported by eddies – an indication that eddies have an important impact on the ecology.

This project combined the perspectives of physical, biological, and chemical oceanography to create a fundamental understanding of how much and where carbon is being taken up by the ocean, and how that might change. 

“In ecological terms, by really paying attention to the physical dynamics, we began to untangle ecological secession.” – Mara Freilich