Research Technical Report

Octopus Gardens and a Whale Fall in Monterey Bay National Marine Sanctuary

King, C., J. Brown, E. Burton, A. Kahn, A. Hartwell, A. Wood, and D. Hardin (March 2020)

Oceanography 33(1):50-51, supplement

DOI: 10.5670/oceanog.2020.supplement.01

Excerpt:

In October 2018, Monterey Bay National Marine Sanctuary (MBNMS) and OET personnel conducted a 34-hour dive to 3,300 m depth at the base of Davidson Seamount, an inactive volcanic undersea mountain off the coast of central California. During the last hour of the dive, we encountered hundreds of female brooding octopuses (Muusoctopus robustus) associated with shimmering water venting from cracks in a relatively small volcanic feature (1 km × 600 m) to the southeast of the seamount (King and Brown, 2019).

Return visits in March 2019 with HOV Alvin and in August 2019 with the Monterey Bay Aquarium Research Institute’s ROV Doc Ricketts confirmed that mixing of warmer venting seawater (up to 10.4°C) with ambient seawater caused the shimmer. This venting seawater is most likely part of a low-temperature hydrothermal system originating at Davidson Seamount (G. Wheat, MBARI, pers. comm., 2019).

MBNMS and OET returned to this area in October 2019 to further characterize the “octopus garden,” to explore a ridgeline on the southeastern apron of Davidson Seamount, and to investigate a small volcanic cone that might host more brooding octopuses.

Suggested Citation:

King, C., J. Brown, E. Burton, A. Kahn, A. Hartwell, A. Wood, and D. Hardin. 2020. Octopus gardens and a whale fall in Monterey Bay National Marine Sanctuary. In: N.A. Raineault and J. Flanders (editors), New frontiers in ocean exploration: The E/V Nautilus, NOAA Ship Okeanos Explorer, and R/V Falkor 2019 field season. Oceanography 33(1):50-51, supplement. https://doi.org/10.5670/oceanog.2020.supplement.01.