Ecosystem connectivity is an essential consideration for marine spatial planning of competing interests in the deep sea. Immobile, adult communities are connected through freely floating larvae, depending on new recruits for their health and to adapt to external pressures. We hypothesize that the vertical swimming ability of deep-sea larvae, before they permanently settle at the bottom, is one way larvae can control dispersal. We test this hypothesis with more than 3×10^8 simulated particles with a range of active swimming behaviours embedded within the currents of a high-resolution ocean model. Despite much stronger horizontal ocean currents, vertical swimming of simulated larvae can have an order of magnitude impact on dispersal. These strong relationships between larval dispersal, pathways, and active swimming demonstrate that lack of data on larval behaviour traits is a serious impediment to modelling deep-sea ecosystem connectivity; this uncertainty greatly limits our ability to develop ecologically coherent marine protected area networks.


Stefan Gary is a physical oceanographer with experience observing the large-scale circulation of the ocean and applying ocean models to better understand the ocean. Stefan is currently finishing an appointment as a Visiting Assistant Professor at Bowdoin College and will start working at Parallel Works, Inc. this summer.  Previously, as a Drawdown Oceans Fellow, Stefan explored how different ocean management practices can contribute to our overall carbon uptake and built the first version of the Drawdown ocean model. At the Scottish Association for Marine Science, Stefan led observations on a long-term repeat hydrographic section in the North Atlantic, the Extended Ellett Line, and developed techniques for automated data quality control from underwater robots and ocean climatology. Stefan now lives in New Hampshire with his family.

In addition to authoring or co-authoring peer-reviewed publications about the North Atlantic Ocean, Stefan has led teams of scientists in a 3-week deep-ocean research cruise and 3 Seaglider missions. He has a total accumulated time at sea of 4.5 months. Stefan holds a PhD in Earth and Ocean Science from Duke University with a research focus on the export pathways of the North Atlantic Overturning Circulation. He also has an M.S. in Theoretical and Applied Mechanics from the University of Illinois at Urbana-Champaign, is a Returned Peace Corps Volunteer, and has a B.S. in Engineering and a B.A. in Art History from Swarthmore College.