Welcome back everyone. It is time to wrap up the posts about this cruise, about a month after we returned from the East Pacific Rise (EPR). For many of us this expedition was life changing, seeing hydrothermal vent communities in person that we had always dreamed about. We had teams and scientists from all over the world helping on this project, providing new perspectives, and diverse skills that led to our success. We were able to complete our main objectives, conduct every dive we planned, prepare for the next cruise, and keep spirits high while being away for the holiday season.
First, I want to say a big THANK YOU to the crew of the R/V Atlantis, as well as the Alvin submersible team for all their help, feeding us, and attending to our scientific or personal needs. We faced very little technical difficulties, but for the issues we did face, the teams were able to remedy them quickly to get us back on schedule. We are very impressed with the Alvin team changing out the main batteries of the sub in the middle of the ocean, when they’ve only done it on shore before! Of course, I also want to thank all the scientists on board who worked diligently, and the film crew for including everyone in their story telling and involving the crew into our science.
The end of the cruise went well. We finished all our sample processing on December 31st, just in time for the new year. To celebrate, Vanessa Jimenez (WWU) took charge and decorated the aft deck and under the A-frame with lights strewn across the various platforms. She created a disco ball out of a Styrofoam ball and aluminum foil and had Alvin’s measurement lasers pointed at it while we danced and had a limbo competition until the clock struck midnight. An unorthodox new year, but one we will never forget.
On the next day, we arrived in port, and spent most of it packing up all our equipment. We did our favorite game of science equipment Jenga back into our storage containers and freight boxes, and divvied up equipment between lab members that we wanted back at the lab. The R/V Atlantis is not returning to the United States until June, so we had to store most of our equipment in the science hold to avoid being in the way of other scientists on the next cruises. The costs associated with shipping internationally, especially with large and heavy science equipment, meant it’d be easier to wait until the ship returns.
The Larval Lab likes to put together these graphics after each of our cruises to remind us of the journey and our achievements during our time at sea. On this cruise we spent 30 days at sea, where we travelled around 2,460 nautical miles (2,831 miles for you landlubbers!) from Puntarenas, Costa Rica, to the EPR, between our study sites, and back to Puntarenas. We had 20 dives with the Alvin submersible, where 12 scientists got to dive for the first time. During these dives we reached a maximum depth of 2553 meters (1.59 miles) and measured the hottest vent fluid to be 353.9°C (669°F)! It got so hot that we actually melted a bit of Alvin’s basket from touching a chimney. We were able to collect many vent fluid, water, microbial colonizer, rock, and animal samples, in addition to sensor readings and successful recoveries and deployments of most our scientific equipment. These tricky sites sometimes made it impossible to locate or reach our old deployments without destroying the habitat, which we are trying to impact as minimally as possible.
The Larval Lab was able to process the 42 settlement sandwiches that we recovered and with the McLane pumps were able to filter 187,856L of water to search for larvae. With the MISO camera and the cameras mounted on Alvin, we were able to take 139,267 pictures and are bringing back a whopping 46 Terabytes of video and data that will assist us for years to come. These images and videos will help us reference any changes in our study sites, and conditions surrounding our deployments and recoveries, as well as provide beautiful shots and animals that we can share with you all. Spending this much time at sea, we end up hitting milestones on the water as well. We had multiple birthdays in addition to the holidays over December, and we even had one scientist, Lauren Dykman submit her PhD and officially become Dr. Dykman.
I’ve talked a lot about our settlement sandwiches and how we’re using them to assess the influence of bacterial biofilms on larval dispersal, but what are we actually finding? When we recovered these sandwiches that we had deployed on the seafloor for two weeks, we split them in half so we could sort through some of the plates for larvae and hand them off to Costa Vetriani’s lab to analyze the biofilms. We put half of the sandwiches in RNA later and the other half we put into ethanol to process back on land. It took us about 10 days of sorting sunup to sundown to get through these 42 sandwiches. We were mostly finding adult polychaetes and gastropods as we sorted, but we did find some larvae! A majority of them were gastropod veligers, which look like teeny, little snails with few whirls, or nectochaetes, which look like small polychaetes with cilia. We found one bivalve veliger and one ophiuroid juvenile. Surprisingly, we did not find the larvae of the abundant Riftia that dominated our sites. However, we still have a lot of samples to sort through on land, so these results are incomplete. Once all our samples are processed we will compare the bacterial communities on the plates to our larval results and see if there are any patterns we can see. We are especially interested in how the sandwiches that developed biofilms first compare to the sandwiches we placed down during this cruise. These photos were taken by Vanessa Jimenez (WWU) and arranged by Dexter Davis (WWU).
Remembering Dr. Diana K. Adams
As we wrap up this series of posts from this cruise, I wanted to take a moment to acknowledge Diane K. Adams (née Poehls) who was pivotal to this project but passed away in 2017. Her doctoral thesis work at WHOI under Dr. Mullineaux titled: “Influence of Hydrodynamics on the Larval Supply to Hydrothermal Vents on the East Pacific Rise” inspired many of the ideas of this EPR Biofilms project. She realized we were studying how larvae were dispersing away from vents, but not how larvae find suitable vent habitats. Her work was groundbreaking at hydrothermal vents, discovering surface winds as a novel potential mechanism for larval dispersal.
She was fearless and determined in her research. She was never daunted by difficult problems and in fact was drawn to them. She did the equivalent of two thesis projects – one deep sea and one coastal during her time at WHOI. She immediately embarked on a cruise to the EPR in 2006 right after an eruption and jumped at the opportunity to be a student star in a James Cameron documentary on the mid-Atlantic Ridge. She approached her science the same way she approached life – with exuberance and joy. An amazing and tireless scientist, but also a strong mentor and advocate for bringing students into STEM. Her students described her as a life mentor who stressed curiosity and work ethic as the foundations of successful science. They are scattered around the field as living proof of her influence.
To remember her legacy, endowment funds are in place at WHOI and Rutgers. Additionally, on Nov 5th, 2021, a plaque was deployed in her memory at a hydrothermal vent site in the Pescadero Basin, Gulf of California during an E/V Nautilus cruise. We wanted to recognize her as part of this project as well, and dedicated our site markers in her name. Her influence on studying the East Pacific Rise hydrothermal vents will continue. Photo of Dr. Diane K. Adams from Rutgers University https://marine.rutgers.edu/team/diane-k-adams/
Thank you to excerpts from Dr. Lauren Mullineaux, Dennis McGillicuddy (WHOI) and Mark Miller’s (former director of EOAS at Rutgers U.) obituaries for assisting in this acknowledgement and telling the story of Diane.
I appreciate the readers for following along this journey with us to further our understanding of hydrothermal vent systems. For now the deli is closed, but more sandwiches will be made when we return to these sites next year and do it all again one more time! Hope to see you there.
If you enjoyed my blog and want to follow me or connect:
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Or the lab:
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Subsurface photos taken with MISO camera, WHOI Dan Fornari. Shawn Arellano, chief scientist, Western Washington University; Alvin Operations Group; National Science Foundation; ©Woods Hole Oceanographic Institution.
EPR Biofilms4Larvae project is a multi-institutional NSF grant: OCE-1948580 (Arellano), OCE-1947735 (Mullineaux), OCE-1948623 (Vetriani).