Seamounts 2007
June 17 - June 24, 2007
June 18, 2007 (Day 2)
Dive T-1100, Pioneer Seamount
Kristina and Laura R. write:
This morning we began exploring Pioneer Seamount, the northernmost station during our expedition.
Despite the choppy seas, the pilots successfully deployed the ROV. We began our dive on the east side of Pioneer Seamount at a depth of approximately 1500 meters.
The ROV Tiburon then moved upward, working toward cones on the flank of the seamount at 1078 meters. Our objectives for the day were to gather rocks to understand
the geologic history of the seamount and to gather bamboo corals for paleoclimate studies.
During the day we saw lots of cool geology and many beautiful and fascinating animals.
We observed chubby nudibranchs, many sea stars, large sponges, abundant crinoids, and many anemones.
Craig writes:
Most tales of the open sea begin with some classic line about the seas being as rough as scorned lover or a furious
ocean goddess unleashing her fury. Both the scorned lover and furious goddess in unison at sea welcomed our first full day out.
Swells were at almost 7 meters providing a rough first night of sleep and rewarding me with multiple skull contusions. The weather also endeavored
to keep the ROV Tiburon on deck but luckily we succeeded in deploying. The newbies this morning participated in the safety
briefing with the long-standing tradition of climbing into the survival suits which gives one the appearance of big red Gumby.
Sea star eating its way up a bamboo coral skeleton.
We have a full scientific compliment representing not only members of MBARI, but UC Davis, Mills College, Stanford University, CSU Northridge, andUniversity of the Pacific.
Today our 8-9 hour dive was on Pioneer Seamount, an old volcano,dense with hard and soft corals, brittle stars, and sponges. One specimen of the soft coral Keratoisis
measured well over 2 meters in height, the trunk at its thickest-a full 5-6cm. We also collected 3 individuals of an undescribed species of nudibranch,
that I collected just one of a little less than year ago on Davidson Seamount. I have been interested in both describing the species and characterizing its genetic variability among seamounts.
Also collected on Pioneer were 3 gastropods of the genus Neptunea, a gastropod typical of the Monterey Canyon complex but previously unknown from seamounts in the region. Overall a productive day and one filled with exciting and important discoveries. This evening we are taking a gravity cores, a 300+ kilogram beast of a device that is dropped to the bottom to take 3-meter long sediment cores.
We saw several Benthoctopus, and
even saw one swimming away.
Neptheidae coral at the base of a
large yellow sponge.