MBARI Ridges 2005 Expedition

Juan de Fuca Leg: August 7–18, 2005
Gorda Leg: August 22–September 2, 2005

 August 18, 2005
Transit day to Newport, OR.

We left the Juan de Fuca Ridge yesterday at about 5 PM toward the port of Newport, OR. We had the wind and swell on our stern and had a fast and smooth ride. We arrived at 3:30PM, a little earlier than expected. We still have to offload our rock samples, the extensometers, and all the gear for those of the science party who are heading home. Several of us will be on board for the next leg, to the Gorda Ridge, so stay tuned for more updates from sea!

It has been a terrific cruise. Thanks to all aboard for their hard work and to Kristin on shore who posted all these cruise updates for us!

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Laura, Brian, Nick and Linda as the ship approaches the dock in Newport, OR. It is a foggy day, and actually colder than it was on the Juan de Fuca!

Linda Kuhnz writes: 
So who are the folks that allow all of this science to happen?  They are the real heros!  We have an amazing crew aboard the Western Flyer and those of us who works for MBARI are always very proud at how well these cruises go.  Thanks to all the people who take such good care of the ship and us!

Gillian Clague writes:
On the ship, a normal day starts at 6:00 am, much earlier for the pilots and crew who go through their checklists before launching the ROV at 6:30. At about 7:45, the vehicle touches the bottom. There is not much free time during the day, only a bit here and there. The ROV is flying over the bottom until 6:00 or 6:30pm, and then, depending on the depth of the dive, has an hour and a half ascent with the pilots still in the control room. The day-time is filled with surreal scenes of lava flows cascading down, pillars and animals, a video game dodging obstacles under the ocean with the pilots in control. There is also a soundtrack to the dives, filled with songs and the pilots' jokes. The room changes as the pilots change shifts, with the music changing from very soft rock to swing, with some hilarious songs thrown in.. I am more and more amazed at the skill of the pilots, especially in the tense moments, both on the bottom and on deck. On the instrument recovery dives, which were the slowest without argument, watching them put the hook through the lanyards of the instruments was literally threading the needle. I love the camaraderie of the ship, listening to the conversations and sometimes just sitting together. The humor is there all the time, no matter what they are doing, even when repairing a ground fault in the vehicle. The conversations over the microphones as the vehicle comes up are always entertaining, as are all the conversations in the control room and in the galley over dinner. When ROV power is finally turned off on deck, it is time for the scientists to jump to, gathering the animals in buckets while the cold water from the frame drips on your back, and identifying the rocks, which is harder than it sounds. We work in the lab for the next few hours, sieving and setting out the samples to dry. Then maybe it's an ice cream before bed, before another day on the Western Flyer starts with all its new adventures.

Fred Pleijel writes:
Polychaetes, or marine bristle worms (relatives to earthworms),  occurred in abundance on the black smokers. Three groups of  polychaetes dominated, scale-worms (Aphroditiformia), Pompeii worms  (Alvinellidae), and vestimentiferan giant tube-worms (now Siboglinidae; see below).

Several different scale-worms were found (image on right is 3 cm long), some with dense bacterial  mats completly covering the scales of the animals. Whereas most scale- worms are predators on small invertebrates, the feeding biology of  these animals is currently unknown, as is the actual relationships  with the bacterial mats. Many shallow water scale-worms live in  association with tube-living animals, and this is likely the case  also here, as they were found in large numbers among the tubes of the alvinellids and the siboglinids.

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Scale from the polychaete above. The veins are vascular structures. The scale is 2mm across.
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Dorsal view of polynoid polychaete (scaleworm) collected at an older CoAxial lava flow. The worm is 3 cm long.

Whereas deep-sea marine invertebrates generally live in very cold  water (around 0°C) and die quickly if exposed to higher temperatures,  hydrothermal vent animals can stand impressing variations in  temperature. Alvinellids, which live on the smokers near the orifices  where the hot water emerges have been recorded to stand temperatures  up to about 80°C! These animals live in tubes, densely aggregated  around the smokers. They feed on particles with the help of a large  number of extensible tentacles, possibly also with the help of the  eight large gills, probably mainly on the abundant chemoautotrophic  bacteria. When occurring in dense aggregations they show quite a bit  of aggressive behavior towards the neighbors, trying to tear them  out of their tubes! The group was discovered in the 1980s and, as far  as known, occur only in association to hydrothermal vents in the  Pacific.

The siboglinids have an interesting taxonomic history. They include  two groups which earlier by some researchers were given the taxonomic  status of phyla, Pogonophora and Vestimentifera. For a long time they  were believed to be closely related to group such as echinoderms,  acorn worms etc, although this has in recent years been show to be  incorrect, and today these two phyla have been “reduced” to the  single family Siboglinidae within the polychaetes. One reason for  this misinterpretation is that siboglinids lack both mouth and gut  and that they for nutrition rely completly on bacteria living in the  body. This lack of gut, together with an otherwise also highly  aberrant morphology (compared to other polychaetes), effectively  masked the identity of the group. Based on a full reinterpretation of  the their morphology, coupled to DNA analyses, we now are certain of  their position. The most recent addition (and no less odd animals)  are the siboglinids described from sunken whale carcasses in deep  waters off California, forming root systems in the bones where they  extract and live of the whale oils with the help of symbiotic bacteria.

Brian Cousens writes:
This last dive had a really special ending for me. We visited the CASM vents in the caldera of Axial Seamount, that back in 1983 were the first hydrothermal vents observed on the Juan de Fuca Ridge.  The vent field is named after the expedition name: CASM is the acronym for Canadian-American Seamount Expedition. In 1983, I had just finished my M.Sc. degree in marine geology at the University of British Columbia, and was working in the Department of Oceanography as a technician. Among the participants in the expedition was my thesis supervisor, Richard Chase, so I knew a bit about what the cruise was all about. The day before the ship was due back in port, I received a phone call at work from a reporter with a Vancouver TV station. He told me that they had intercepted a radio transmission from the research ship and the shore facility, and that the radio discussion was very excitedly talking about hot vents, strange worms, and other odd things on the sea floor. Could I give them an explanation of what all the excitement was about? After talking for a while on the phone, the reporter asked if I could come to the station to do an interview, and of course I said yes! So I did a quick bit of research, drove to the TV station, did an interview, helped with some computer graphics, then went back to work. Sure enough, they played the interview on the 6PM news in Vancouver, and I thought that was pretty cool. The next day, my mother phoned me from Montreal to tell me that some of the interview was also broadcast on the CTV national news that night!  REALLY cool......  So it was a "blast from the past" to actually see the CASM vents for the first time, after playing a small role in making it national news in Canada.

Captain Ian Young at the controls of the crane, hoisting aboard the elevator and extensometers.

We are now tied up at the dock on Newport.  The ship isn't moving, but we still feel like we are weaving—dock walk!  This is my third cruise on the Western Flyer, and I am still impressed by the entire experience. The crew, the pilots, and the science staff all get along so well that 18-hour work days are not just productive but fun as well.  Hats off to everyone involved—I'm already looking forward to next year's cruise!

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A view of the CASM hydrothermal vents, with gray "smoke" exiting from the chimney in the right.  These chimneys were amazingly fragile, compared to others that we have encountered on this cruise.

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