MS Thesis Defense: Andrew Hyde

The Masters Thesis Defense of Andrew Hyde will be presented by the Department of Marine Sciences in seminar room G201 on the ground floor of Murray Hall, UNC at Chapel Hill. Live stream can be made available upon request. This event will be held on Wednesday, December 6th at 10:00 AM.

Title:  Putting Orca Basin on the map: characterizing the bacterial community in the world’s largest deep sea brine pool

Abstract: The Gulf of Mexico contains the world’s largest anoxic hypersaline pool, Orca Basin. The water contained in this 400 km² bathymetric depression is roughly eight times as saline as the overlying seawater. The resulting density contrast prevents the 200 m thick brine from mixing with seawater, creating an interface that traps particles of organic matter falling through the water column. The concentrated organic matter at the interface is hypothesized to host a thriving bacterial community that has yet to be characterized. Here, I present the results of the first molecular survey ever conducted on the interface and brine pool of Orca Basin. I discuss how the bacterial community changes along a 550 m vertical transect with regards to oxygen, salinity, and organic matter gradients. Finally, a comparison of the geochemical and bacterial composition of Orca Basin to brine pools in the Mediterranean and Red Seas reveals the uniqueness of Orca Basin in a global context. This research adds to our current knowledge of biodiversity in global hypersaline habitats and has implications for our understanding of sulfur and carbon cycling in extreme environments.