Friday, December 4, 2009
Success!!
After joining the next leg of the cruise, spearheaded by Andreas Teske from UNC- Chapel Hill (teskelab.wordpress.com), and waiting a long 10 days on board, Kristen and Meg had their dive in Alvin on December 2nd. With much anticipation, they headed down with the main goal of recovering the two thermocouple arrays that had been deployed at the end of our cruise. What would the newly formed vent deposits look like? Will they have grown through the titainium cages? Will the temperature loggers have functioned properly? We were very eager to see what we would find...
Success!! A beautiful mushroom had grown through the array and it's stalk engulfed four of the eight thermocouples! When we checked the temperatures, one in the wall read 120˚C, and another 280˚C, and two that read 300˚C and 302˚C were indeed inside the vent fluid conduit (based on observations of the chimney wall recovered in the array- see photo below). We also sampled the white flange material in the middle portion of the mushroom above the stalk. We recovered the temperature logger and once back in the lab, downloaded the 15-day temperature records and subsampled the chimney for microbial analyses.
At the second array, a chimney had also grown in the titanium cage, much to our delight- since one had not grown during the previous 6-day deployment. Temperatures inside the chimney read 180˚C, 200˚C, and 260˚C. Again we recovered the logger, array and chimney. In addition, the gooey white and orange filamentous biofilm had formed over much of the chimney and array. Once back in the lab, we collected this gooey material for analysis, downloaded the temperature records, and subsampled the small chimney.
We are very excited at these initial results and anxious to analyze the samples further in our labs back in the states. The Reysenbach group will use molecular biological tools to reveal the members of the microbial communities that developed in the 15-day old chimneys and compare the communities to those that developed during the shorter array deployments (see previous blog posts).
Our Recent Guaymas Impressions:
While we have certainly not been idly passing the days, being on board awaiting the recovery of our instruments 1.25 miles below us has afforded us opportunities to enjoy more of the amazing scenery and happenings around us. In particular, the sunsets have been gorgeous night after night. Below are four of our favorite shots of the sun slipping behind the hills of the Baja of California.
On one afternoon that was forecast to be a little "stormy," beautiful rainclouds formed on the horizon and gave us glimpses of several rainbows throughout the day. During recovery, Alvin (with Anton on top) happened to float right in front of one!
The other spectacular sight (sea lion aside, because it's quite difficult to photograph one in the sea at night!) has been the bright full moon. It was completely full the night of December 2nd, but it has been giving us days of stunning moonrises, moonsets and a ship bathed in moonlight. On the night of December 1st, we were treated to an auspicious and remarkable sight- a moon halo! Moon halo's have a diameter of 22˚ and form as the moonlight is refracted by "diamond dust" (hexagonal ice crystals) in the upper atmosphere.
Legend has it that these moon rings are a sign of bad weather to come, but we preferred to think of it as a good portent for our impending recovery dive the following day. Given our successes and the calm seas that have followed, I think our interpretations were correct!
We hope you have enjoyed following our Guaymas Expedition 2009 cruise blog! Meg and Kristen, on board for another few days, will soon leave behind the sunny Mexican days for the cold winters of Cape Cod and the Pacific Northwest- thank goodness for fireplaces... and chimneys!
Tuesday, November 17, 2009
It's a Wrap
Lauri’s Guaymas Impressions:
17 November: Where did the time go? It is officially our last day at sea and the weather has allowed Alvin one last dive. Professor Brian Cox of the BBC accompanied Chief Scientist Anna-Louise Reysenbach and pilot Mark Spear aboard Alvin to capture some deep-sea footage and observe the sub’s operations.
Even with the rush to finish projects and pack up lab equipment, some of us made time to join Chief Engineer Jeff Little for a tour of Atlantis’ engine room.
It’s a spatially efficient combination of high tech controls and really big, noisy machinery that is divided into roughly three rooms: control, generators, and propulsion. Since the ship is ‘diesel-electric’, all of the power that controls everything from stateroom lights to deck equipment to the ship’s mobility is generated by an array of monster diesel engines.
In case you were wondering, all of that power consumes about 1500 gallons of diesel fuel per day when stationed at a dive site.
Alvin’s last dive for this cruise ended about 5 p.m., just in time for dinner!
Like any vehicle operating in its environment, Alvin needs a bath now and then, and since this was the last dive, it was also bath time. So once the sub was emptied of it’s human cargo, everybody helped spend last moments of daylight scrubbing and rinsing.
We arrive in port late tonight after seven dives and ten days at sea. This has been a fun and productive cruise and I hope that you enjoyed following us as we explored the Guaymas basin hydrothermal vents! Keep checking this blog, as Meg and Kristen are still at sea and will retrieve the 2 thermocouple arrays that are still on the seafloor.
Monday, November 16, 2009
A Bit of Weather
The current motion of the ship and views of choppy seas are a stark contrast to the beautiful calm weather we experienced during the initial part of our cruise. It appears that a large high pressure system over Utah and Colorado has kicked up the winds in the Gulf of Mexico and we've seen sustained winds of around 25 knots since late last night. All that wind has stirred up the ocean and we are pitching and rolling in the 6-9 foot swells. Unfortunately, today's dive was canceled as this weather makes it unsafe to launch and recover Alvin (see previous dive post).
However, no time is wasted at sea and we've been busy catching up with our sample logs and lab work.
Sadly, our cruise is also rapidly coming to an end, with tomorrow being our last day at sea. Hopefully the seas will have calmed down so we can send Alvin down one last time for this expedition.
Sunday, November 15, 2009
How, What, Where
Much of our focus on thermoacidophiles at deep-sea hydrothermal vents has centered on an archaeal lineage known as the deep-sea hydrothermal vent Euryarchaeaota group-2 (DHVE2) as they were the first obligate acidophiles described from these environments. The first cultivated organism within the DHVE2, Aciduliprofundum boonei, was originally isolated from the Eastern Lau Spreading Center in 2006. Since then, we have cultured more representatives from the Mid-Atlantic Ridge, East Pacific Rise and again from Lau (see figure below). Cultivation of these new isolates continues to demonstrate the peptide scavenging lifestyle of the DHVE2 and is beginning to show some biogeographic patterns with respect to 16S rRNA gene diversity. Culture independent techniques, such as high-throughput pyrosequencing, are also beginning to show correlations between the type of vent feature and the presence of the DHVE2.
Neighbor joining tree of cultured representatives of the DHVE2 based on 1261 unambiguously aligned nucleotides of 16S rRNA gene sequences. Scale bar represents 10 substitutions per 100 nucleotides.
On our current cruise, we have been using quantitative-PCR (QPCR) to determine if the DHVE2 are present in vent deposits from the Guaymas Basin. Surprisingly, preliminary results have demonstrated the presence of these thermoacidophiles despite the higher pH of the Guaymas fluids. Below is a photo of a vent deposit collected during this cruise where the DHVE2 have been detected by QPCR.
Lauri’s Guaymas Impressions:
14 November: The Bridge is the tidiest place I’ve seen on Atlantis, although now I have a much better understanding of the term ‘ship shape’. It’s bright, shiny, and loaded with sophisticated technology surrounded by a panorama of windows. Chief Mate Peter Leonard recently explained the basics of the ship’s control and navigation systems to me as I stared in wonder. Thanks to an array different GPS technologies, some linked with the ship’s thruster controls, Atlantis can automatically remain within nine feet of a desired heading even in rough seas.
Computers and software have greatly enhanced navigation safety as well. Now most ocean going vessels are required to input their course and ship information into a system that makes the data available for other ships to see, thus enabling safe navigation especially in low visibility. But there is still some old-school equipment in use, my favorite being the wooden heading indicator from the original Atlantis called “the blocks”.
Saturday, November 14, 2009
An Amazing Ride
Since Alvin isn't designed to cruise along the water's surface, it needs to be towed a short distance back to Atlantis. This is a multi-step process that begins with two swimmers (Carl and Jim, today) and a driver (Jerry) racing a zodiac out about a half mile from the ship to the general area where Alvin is expected to surface. Once the sub is spotted we move closer so the swimmers can attach the sample basket stabilizer. This braces the big tray-like structure on Alvin's bow that carries all of the precious samples when the sub is lifted from the water.
A tail hook is then attached to the sub and the swimmers are free to show off their diving skills. Finally, the Avon's job is done and we return to the ship.
I felt incredibly free and yet vulnerable in the little zodiac as I watched the bulk and safety of Atlantis shrink into the distance. The vast seascape of rolling swell and chop provided me with a new perspective not just of the ship, but also of the abyss below and all the beauty and mystery within it.
Friday, November 13, 2009
Animals Abound
At the hydrothermal vents, the microbes that thrive on hydrogen sulfide provide the energy needed to support a prolific community of vent-associated animals. The quintessential vent animal is the tubeworm Riftia pachyptila. These animals have evolved to become completely dependent on symbiotic bacteria to provide them with nutrients. In fact, the worm is quite simplified and has a modified gut called a trophosome that is filled with cells that contain symbiotic bacteria. The worms simply need to supply the bacteria with hydrogen sulfide, nitrogen, and CO2 and the microbes use these simple building blocks to produce organic molecules that they share with their host. This teamwork strategy between the microbes and the tubeworm is highly successful allowing the worms to reach incredibly large sizes (some are over a meter long) and often these animals dominate areas around hydrothermal vents. Once you get over the grandeur of the tubeworm, you start to notice that there are a a lot of smaller creatures hanging around that are using similar strategies to survive in the deep ocean. Not surprisingly, there is a rich diversity of species in the vent communities that have figured out ways to either form direct partnerships with microbes or to live by eating the microbes or other animals.
Lauri's Guaymas Impressions:
12 November: Alvin's third dive was delayed for a few hours due to a technical issue, but eventually Mircea and Meg were sent on their way.
Pilot Mark's cool fisheye lens.
We began production of the Best of Video DVD today, which will summarize the highlights of all the dives. There is some beautiful footage of the sea floor and what Fengping described as "massive dark lovely creatures shinning there, bubbling their story".
Alvin arrived at twilight, and brought with it many animal specimens such as tubeworms (and their hangers-on), more sulfides, and the thermalcouple array, which was coated with about eight inches of sulfide material and (hopefully) some microorganisms. The activity level really picks up in the evening, with processing continuing until well into the night.
Thursday, November 12, 2009
Butterflies at Sea
Visit this page for her personal account of the dive.
Lauri’s Guaymas Impressions:
Tuesday, November 10, 2009
Dive Time
The morning began with a great sigh of relief as we obtained our official diplomatic clearance to dive. We wasted no time and started the dive, rolling Alvin out of its hanger just after breakfast. The sky was clear and sunny, seas were calm- all systems finally a “go”!
Bruce Strickrott, our Expedition Leader, piloted Alvin, with Meg Tivey and Paul Craddock aboard as scientific observers. Two observers, in addition to the pilot, are on each dive- the more experienced observer peers out the port-side porthole and the less experienced watches out the starboard porthole.
This was Paul Craddock’s first dive in Alvin!
The primary objective of this dive was to deploy the thermocouple array. This instrument allows us to study the microbial colonization of newly precipitated vent deposits- read more about this instrument and previous deployments at Lau Basin (will link to Lau blog specific post). The thermocouple array was successfully deployed at the “Busted Mushroom” site.
Lauri's Guaymas Impressions:
10 November: Hooray, Alvin and crew got to dive today! After about 45 minutes of prep, the sub was hoisted into the water and detached from its lines.
Our afternoon was filled with last minute sampling set up and another science meeting, as well as yet another delicious lunch. The food is really spoiling me.
Alvin surfaced about 4:15p.m. And was greeted by a boat carrying swimmers and a towline. The sub's white body contrasted beautifully with the blue-green water. After hoisting Alvin and crew back on board, sulfide samples were quickly brought to the lab for analysis. And then we ate fresh mahi mahi for dinner.