2016 Expedition
Coast Trader wreck

Seeps and Ecosystems of the Cascadia Margin

June 1 – 20, 2016

Expedition Partners

Lead Scientist
Expedition Leader

Methane is a powerful greenhouse gas and an important commercial resource that fuels many elements of our lives on land. Scientists are beginning to understand the complex and varied ways methane fuels life beneath the sea as well. Nautilus will study methane seep habitats along the length of the Cascadia Subduction Zone, from southern British Columbia to northern California. Several sites along the Washington coast are well-studied ecosystems fueled by gas hydrate - a crystalline, consolidated chemical ice made of methane. Oceanographic and geologic conditions suggest gas hydrate and methane seep habitats should stretch all along the Cascadia Subduction Zone, but a comprehensive study of the region has never been done. Advanced mapping technology, like the Kongsberg multibeam system on Nautilus, allows scientists to detect methane bubble plumes in the water column and describe the extent of these habitats.

On this expedition, Nautilus and her Corps of Exploration will use mapping tools to survey the extent of methane seeps along the Pacific Northwest coastline. As habitats are identified, the ROVs will dive on these targets to investigate the structure and communities they support.

Current research indicates warming oceans will rapidly change the stability of these seafloor gaseous reserves, which may in turn have large effects on oceanic dissolved gas concentrations and the release of greenhouse gases into the atmosphere. A well-explored baseline understanding of this dynamic ecosystem will be essential for understanding changes as they occur.

During this cruise, Nautilus will also explore the wreck of the World War II freighter SS Coastal Trader.  The ROVs will conduct the first visual survey of this cultural heritage site as well as assess its condition and remaining vessel stability.  

Meet the Team

Selected Publications


Malcher, F., White, P. (2023). Acoustic monitoring techniques for subsea leak detection: a review of the literature . National Physical Laboratory Report AC21: 22. https://eprintspublications.npl.co.uk/9781/1/AC%2021.pdf


Merle, S. G., Embley, R. W., Johnson, H. P., Lau, T.-K., Phrampus, B. J., Raineault, N. A., & Gee, L. J. (2021). Distribution of Methane Plumes on Cascadia Margin and Implications for the Landward Limit of Methane Hydrate Stability. Frontiers in Earth Science


Castillo, C. M., Klemperer, S. L., Ingle, J. C., Powell, C. L., Legg, M. R., & Francis, R. D. (2019). Late quaternary subsidence of santa catalina island, california continental borderland, demonstrated by seismic-reflection data and fossil assemblages from submerged marine terraces. Bulletin of the Geological Society of America 131(1-2): 21-42.


Baumberger, T., Embley, R., Merle, S., Lilley, M., Raineault, N., Lupton, J. (2018). Mantle‐derived helium and multiple methane sources in gas bubbles of cold seeps along the Cascadia Continental Margin. Geochemistry, Geophysics, Geosystems 19(11): 4476-4486.
Brennan, M., Cantelas, F., Elliott, K., Delgado, J., Croff Bell, K., Coleman, D., Fundis, A., Irion, J., Van Tilburg, H., Ballard, R. (2018). Telepresence-Enabled Maritime Archaeological Exploration in the Deep. Journal of Maritime Archaeology 13(2): 97-121.
Delgado, J., Cantelas, F., Symons, L., Brennan, M., Sanders, R., Reger, E., Bergondo, D., Johnson,D., Marc, J., Schwemmer, R., Edgar, L., MacLeod, D. (2018). Telepresence-enabled archaeological survey and identification of S/S Coast Trader, Straits of Juan de Fuca, British Columbia, Canada. Deep Sea Research II 150: 22-29.
Dziak, R., Matsumoto, H., Embley, R., Merle, S., Lau, T-K., Baumberger, T., Hammond, S., Raineault, N. (2018). Passive acoustic records of seafloor methane bubble streams on the Oregon continental margin. Deep Sea Research II 150: 210-217.
Everett, M., Park, L. (2018). Exploring deep-water coral communities using environmental DNA. Deep Sea Research II 150: 229-241.
Powell, A., Clarke, E., Fruh, E., Chaytor, J., Reiswig, H., Whitmire, C. (2018). Characterizing the deep-sea sponge grounds of Grays Canyon, Washington. Deep Sea Research II 150: 146-155.
Seabrook, S., De Leo, F., Baumberger, T., Raineault, N., Thurber, A. (2018). Heterogeneity of methane seep biomes in the Northeast Pacific. Deep Sea Research II 150: 195-209.
Yoklavich, M., Laidig, T., Graiff, K., Clarke, E., Whitmire, C. (2018). Incidence of disturbance and damage to deep-sea corals and sponges in areas of high trawl bycatch near the California and Oregon border. Deep Sea Research II 150: 156-163.