Award: OCE-1756947

Intellectual Merit. The primary focus of this research was on the transport and fate of semi-soluble hydrocarbon compounds in the ocean. The goals of the project were to develop and apply a methodology to quantify hydrocarbon discharge rate from ocean point sources, to quantify the extent to which semi-soluble hydrocarbons dissolve into the Ocean?s interior, and to follow the microbial response to those dissolved hydrocarbons. Through studies at the Coal Oil Point Seep Field and in the Gulf of Mexico, we succeeded in developing a drone-based system capable of quantifying atmospheric flux of volatile hydrocarbons from the Ocean surface at hydrocarbon seeps, and we further collected samples from the underlying seeps that should enable the calculation of total flux. We also investigated the microbial response to input of soluble hydrocarbons in the Ocean?s interior and identified both the microbes and biochemical mechanisms involved in the response. This research resulted in nine publications, with additional publications in preparation for submission. Broader Impact. The broader impacts of this award focused on providing research opportunities for more than a dozen undergraduate students and a half dozen graduate students. These research opportunities included laboratory research projects, as well as field research experiences, and were formalized through participation in multiple offerings of a course titled field studies in marine biogeochemistry and through REU opportunities. Field research experiences included small boat operations combined with unmanned aerial vehicle flights at the Coal Oil Point Seep Field, as well as participation on the SEEPS? 22 research expedition to the Gulf of Mexico. Participants on the SEEPS? 22 expedition gained experience with field sampling and investigation, use of unmanned aerial vehicle technology at sea, use of the deep submersible vehicle, Alvin, and use of the autonomous underwater vehicle Sentry. Last Modified: 05/04/2023 Submitted by: David L Valentine