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Biodiversity in the deep ocean

tubeworms photo

Tubeworms, crabs, and other fauna at a hydrothermal vent on the East Pacific Rise, as photographed through HOV Alvin's viewport (LADDER 1 cruise, Woods Hole Oceanographic Institution)

My work in deep-sea biodiversity addresses “species” and “habitats” (the same two sub-goals of the biodiversity goal of the Ocean Health Index). For “species,” my expertise is mainly benthic invertebrates. For "habitats," in the past decade I have focused on deep-sea hydrothermal vent fields. I co-authored the chapter on vents and seeps for the first United Nations World Ocean Assessment.


Regional projects

Hydrothermal vents on the East Pacific Rise

Our current project at the EPR is "Trajectories in functional diversity after disturbance at vents on the East Pacific Rise," funded by the National Science Foundation. Our first cruise for this project was AT42-21 with HOV Alvin in Dec. 2019. See Mullineaux et al. (2020) Proc. R. Soc. B.,

larvae photo

Mills, S.W., Beaulieu, S.E., and Mullineaux, L.S. (2009) Photographic identification guide to larvae at hydrothermal vents. Woods Hole Oceanographic Institution Technical Report WHOI-2009-05, 108 pp.,, DOI: 10.1575/1912/2996. (K. Joyce, WHOI)


Hydrothermal vents in the Pescadero Basin

This project funded by the Dalio Explore Fund included a research cruise in Nov. 2017 to hydrothermal vents in the Pescadero Basin, Gulf of California. The biological component of this multi-disciplinary project is motivated by: How are the differences in macrofaunal community structure governed by the unique geochemical regimes at Pescadero Basin, and what are the implications for the connectivity and biogeography of deep-sea communities?


Hydrothermal vents in the Marianas Trench Marine National Monument

In 2009 the U.S. established its first Marine Protected Areas for deep-sea hydrothermal vents in the Marianas Trench Marine National Monument. These vents are distributed along the Mariana volcanic arc and back-arc spreading center. We participated on R/V Yokosuka cruise YK10-11 with HOV Shinkai 6500 in 2010 and by telepresence on a NOAA Okeanos Explorer cruise in 2016.


Global projects

Global distribution of submarine hydrothermal vent fields

I created and maintain the online InterRidge Global Database of Active Submarine Hydrothermal Vent Fields, with recent Version 3.4 published in PANGAEA.


Functional traits of species living at deep-sea hydrothermal vents

Chapman ASA, Beaulieu SE, Mills SW, Mullineaux LM, Bates AE, et al. (2019) sFDvent: A global trait database for deep‐sea hydrothermal‐vent faunaGlobal Ecology and Biogeography, doi: 10.1111/geb.12975


Ecosystem services from deep-sea hydrothermal vents

I conducted an interdisciplinary project "Assessing the values of ecosystem services at deep-sea hydrothermal vents," with Porter Hoagland (Marine Policy) and Chris German and Maurice Tivey (Marine Geology and Geophysics Dept.), funded by The Joint Initiative Awards Fund from the Andrew W. Mellon Foundation. We recently published a chapter in Natural Capital and Exploitation of the Deep Ocean.

In association with this project, I presented with colleagues Thomas Graedel (Yale Univ.) and Mark Hannington (GEOMAR) a session titled "(When) Should We Mine the Seafloor?" at the 2017 AAAS Annual Meeting.


Previous projects

octocoral photo

A stalked octocoral, perhaps a seapen with an isopod on it, and polymetallic nodules at 5000-m depth at H2O. (K. Smith, MBARI, and S. Beaulieu, WHOI)

Benthos at abyssal depths under the North Pacific Subtropical Gyre

Biodiversity at hydrothermal vents on the Galapagos Rift

"Life under glass houses" (sediment communities at Station M)

"Life on glass houses" (glass sponge communities at Station M)

Zooplankton in Monterey Canyon


Funding Agencies

Recent deep-sea research funding from the National Science Foundation, the Dalio Explore Fund, and the Mellon Foundation


Recent deep-sea research collaborators include:

Mullineaux lab group


sFDvent working group