As the year and the cruise come to an end, I hope you achieved your New Year’s resolutions from last year. I should think one of them was to learn more about microbes (bacteria, archaea, viruses). Don’t worry, I’ll help you out with that one!
In these hydrothermal vent communities that we’ve been studying, microbes are the entire reason these ecosystems are formed and can thrive. These tiny organisms provide food at the base of these food webs and create symbiotic relationships with many of the animals that call the EPR their home. As you know in the deep-sea, light does not penetrate, especially not 2500m deep. While the photos and videos we’ve been sharing illuminate these animals, they typically live in complete darkness.
In most ecosystems, food starts with photosynthesis, when plants create biomass using energy from the sun. In hydrothermal vent habitats chemosynthesis occurs instead, where microbes use chemicals, like hydrogen sulfide and methane, instead of sunlight to create biomass. This allows the typically food poor deep-sea to become a high-density oasis of life around hydrothermal venting fluid, or methane seeps like our lab’s SALT project. Microbes play all sorts of roles in many ecosystems, and even in our own bodies. It’s been found that there is more microbe DNA in our body than our own human DNA, meaning we’re mainly microbes.
Study site, Tica.
For this project, since we know many of these animals rely on microbes to survive, we’re trying to explore the relationship between microbes that have created bacterial films on surfaces and larvae looking for a place to settle. Do they release a chemical cue that tells the larvae this is a good place to grow up and live? We are also interested in identifying these bacteria, understanding the order they appear, and the characteristics of their biofilms. Bacteria are incredible small, so how do we obtain them?\
The simplest way to obtain bacteria from the deep-sea is through filtering water samples. You essentially suck a water sample through a filter with a small pore size, like 22um (0.022mm), trapping the bacteria, and then can extract the DNA in a molecular laboratory and sequence it to identify the species.
AL5132 MAJOR Sample.
AL5123 MAJOR Sample.
AL5131 MAJOR Sample.
The main way we’ve been collecting water samples is through Donato Giovanelli’s MAJOR Samplers, and through Tanika Ladd’s (WWU) niskin bottles that we talked about earlier. These MAJORs collect 750ml samples that can be filtered for microbes and geochemical information from targeted sites. On this cruise, we’ve been targeting within the hydrothermal flow, and even within the hot black smoker venting fluid. These samplers are very temperature tolerant, with Donato estimating they could sample water up to 800C. On this cruise the hottest water we’ve measured from a smoker was 359.3C! At that temperature not even microbes survive, but we can still extract chemical data from the water. We can utilize spectrophotometry, ion chromatography, and inter-coupled plasma mass spectrometry (ICP-MS) to measure the sulfide, iron, and trace metal concentrations within. These MAJOR samples are also filtered through a 0.22um filter and will be sequenced for bacterial genetic information later. Donato’s lab is also collecting chimney pieces that will be used for geochemical analysis. The chemicals in the water are important as they control what microbes can survive.
A sandwich recovered with visible bacterial mat.
The main way we are collecting bacteria, however, are through our sandwich deployments that I keep talking about. Half of these deployments have been sitting on the seafloor for over a year in a mesh bag that allows bacteria to grow without letting animals colonize and settle on the plates. When we recover them, the larval lab sorts through them under the microscope, picking out any organisms that have attached to them so we can identify the animal communities and larvae, and then we pass them over to Costantino Vetriani’s lab.
They take the plates and freeze them at -80C, and back on land they will take photos of these biofilms, to see the physical characteristics of them, and then extract the DNA from them. With this DNA metagenomics and proteomics can be done. Metagenomics will sequence the entire community, telling us what microbes are there and their potential functions, while proteomics will tell us what they’re actually doing in the community.
While the “omics” don’t separate bacteria species, there are a few tricks to isolate them from each other. The first method, which sounds pretty cool, is dilution to extinction. When you have a water sample that contains bacteria, you keep diluting it, separating it into smaller and smaller concentrations, until you have a single bacterial cell in your final container. You now have a tube with a single species that you can turn into a culture, a growing group of a single species. You can tell you have a successful culture from one of three ways: 1) the liquid is murky, 2) there is a biofilm growing on the side of your tube / at the surface of the water, or 3) using a microscope.
Bacterial cultures – left with “murky” visible culture, middle with nothing, and right with pink indicating oxygen presence.
Various cultures in the Vetriani Lab.
But how do we feed and grow these cultures? Bacteria, just like us, have specific requirements that they need to survive. In this project we are particularly interested in the hydrothermal vent adapted, high-temperature and hydrogen-consuming bacteria. We can target these “thermophiles” by adding a hydrogen food source to these tubes. Only bacteria that consume this hydrogen will be able to survive in this tube. We also use anaerobic seawater, meaning there is no oxygen in the tube, to eliminate bacteria that consume oxygen. Within these tubes is a chemical that turns the seawater pink if oxygen is present. To select for high-temperature bacteria, we can place these tubes in incubators, where only the temperature tolerant can survive. On board we have a 35C and 80C incubator that allows us to do this.
While the sandwich plates are taken back home to study, we are still creating cultures on board through other methods. Throughout the Alvin dives, we have been collecting samples opportunistically that may have biofilms we can extract. We’ve collected mussels and pieces of rock or chimneys from our study sites that we can extract the bacteria from. This is a process that is needed to be done quickly, and using sterile protocols to avoid any contamination with bacteria we aren’t interested in. After a dive it’s typical to see members of Costa and Donato’s lab rush out to the basket with trays of aluminum foil and gloves, extracting the chimney pieces and rushing them to the analytical lab. Using highly sophisticated techniques of hammers and screwdrivers, the chimneys are broken into smaller pieces that can be added to a tube with seawater and shaken to separate the bacteria from the rocks. This new concoction is what we will add to our hydrogen tube that we can dilute to extinction later.
It’s no easy task to retrieve the sandwiches with biofilms from the seafloor either. To preserve these biofilms for analysis, we make use of a solution called RNA later. It’s a mixture of Ethylediaminetetraacetic acid (EDTA) (say that 10 times fast!), sodium citrate, and ammonium sulfate. It’s essentially a super salty mixture that prevents degradation of DNA and RNA, but kills the organisms. We’ve made nearly 80L of RNA later on this cruise to process these sandwiches.
Above: Avanthika Bharath (Rutgers) and Olivia Cannon (Rutgers) chisel collected chimnies. Below: Matteo Selci (Naples U.) and Olivia Cannon extract biofilms from pieces of chimney.Tanika Ladd (WWU) makes RNA Later with purpose.
Costa Vetriani at the sandwich recovery basket – the color coded lunchbox, and RNA later tubes in the top left.
When we recover these sandwiches, we place each into a separate container to keep samples isolated from each other. They are either placed in our color-coded “lunchbox”, or in Costa’s RNA later sampling tubes, that hold 2L of RNA later. The sandwiches not placed in these sampling tubes are transferred to RNA later as soon as possible after recovery.
A final way we’ve been collecting microbes on this cruise is through a round colonization device. This instrument has mesh on either side that allow bacteria to colonize material inside, similar to our sandwich bags. These were placed around Riftia tubeworms at our study site Tica, emulating rapper Flavor Flav, and recovered after a few weeks. This also allows us to assess a younger community of bacteria at these sites, compared to the chimneys and rocks that have developed them for longer, exploring the succession (order) bacteria colonize.
The “Flavor Flav” colonizer deployment.
Deep-sea science is inherently challenging, and sampling microbes are no exception. These systems that we study are ultimately controlled by the microbes that live there. Microbes play a larger role in all ecosystems than you might expect. By analyzing these samples, we’re hoping to unravel the mysteries of how these communities form and persist. Make it next years resolution to learn more about the microbes around you!
The science party adorn festive hats. Photo by JP Isaacs.
As many of you know, we are sailing through the holidays on this research expedition. The end of the calendar year also happens to be when the weather is best at the East Pacific Rise. As we wrap up our Alvin dives and get ready to start our transit home, the lab is in the middle of our sample processing. We finished our recoveries, having put our sandwiches down two weeks ago, and we’re now picking through the animals that have settled or colonized them.
While this is the first Christmas most of us have ever worked, we are still doing our best to be festive, and had planned events to make this a memorable time at sea. It’s difficult for many of us to be missing the holidays, but we are lucky to have internet access, and enough of it to even video call all the way out in the middle of the ocean. We miss our families back home but spending nearly four weeks at sea together has created a new family we can celebrate with.
The crew on board has done an exceptional job decorating the ship and making food throughout the month to make us feel more at home this holiday season. In the galley tinsel and Christmas lights are strewn about the entryway and support poles. In the movie lounge what feels like a hundred snowflakes hang from the ceiling, with a Christmas tree and presents in the corner, and a small fireplace in front of the TV. In the main lab we created a festive scene with our own snowflakes, lights, and used red ribbon to make candy cane support poles. My favorite part is one of our SSSGs (Shipboard Science Support Group), Allison, had printed Santa hats in various sizes and placed them on all the pictures around the ship. In the galley a fish identification guide sports some very well-fitting hats.
This year is unique in that Christmas day also falls on the last day of Hannukah. One crew member, an Able-Bodied (AB) named Alex went out of her way to celebrate for those on board. As someone who celebrates both, I really appreciated her going out of the way to make sure I felt included. She made a variety of Jewish foods like matzah ball soup, latkes, and kugel. While she made enough for everyone to try, she made sure to set aside plates for the Jewish scientists. She even stopped me in the morning and had a request, that she paid for in gelt (chocolate coins).
Typically, we light candles for Hannukah, but that isn’t the safest thing to do in an enclosed space, so we had to get creative. Some of us called home to light candles with our families, and others brought LED menorahs to safely celebrate in our state rooms (although mine was so bright I hope it didn’t blind my roommates).
The Christmas festivities began the night before. After spending most of the day and some of the evening sorting, we earned a break. We spent the rest of the night watching Christmas movies and decorating Styrofoam cups to be shrunk with the Alvin dive the next day. There were passionate discussions about what is the ultimate Christmas movie. There were many votes for Die Hard, the Grinch, some for the Gremlins and the Polar Express, but for Christmas Eve we ultimately decided on watching Elf. After that we watched the Nightmare Before Christmas, and then Rudolph the Red Nosed Reindeer. Once the cups were finished, we all headed to bed, hoping Santa would visit us in the middle of the ocean.
Christmas Eve sorting. Photos by Lance Wills.
Christmas Eve movie watching.
In the morning it looked like Santa had come! In front of each of our doors were knitted hats made by the ladies of the St. John’s Bethel Baptist Church in Charleston, South Carolina. They came in all colors and sizes, some fit better than others, but we were grateful for gifts out at sea. The main lab is also quite cold so they will be used!
Many of us began Christmas day calling our loved ones, opening presents, and participating in our \ traditions with our families from afar. Science operations were still happening, we still had a Christmas Alvin dive. Wyatt Heimbichner Goebel (WWU) and Susan Mills (WHOI) would finish up our recoveries at Tica and Riftia Mound. As the science team approached the aft deck where the launch occurs, we were welcomed by Alvin pilot Bruce Strickrott wearing a flashing Santa hat, SSSG Allison covered in tinsel, a manta ray hat with reindeer antlers, and ornaments, and AB Mike Sessa in a full elf costume. The Alvin swimmers were also adorning their own Santa hats. This had to be one of the most unique Alvin launches, although watching the Halloween Alvin recovery where the swimmers were dressed like hotdogs may have it beat. As Santa’s helpers descended into the water on top of Alvin, they began their journey down to the seafloor.
Morning Alvin launch. Photo by Shawn Arellano.
Dexter Davis and Tanika Ladd sort samples. Photo by Shawn Arellano.
White bacterial films on settlement sandwich.
While our scientists completed their dive objectives, there was still a lot of science processing to be done back on the ship. Dressed in hats and Tanika in her Santa jumpsuit, we sorted through our sandwich deployments until the submersible returned. These sandwiches can vary in the texture and the amount of bacteria on them, and the one I was sorting through had a white, filamentous bacterial mat on it. Not quite the White Christmas I was dreaming of, but while we played Christmas music, it felt somewhat fitting. Throughout the day some Christmas presents were exchanged, ugly sweaters were prepared for the contest after dinner, and a lot of candy was eaten. Apparently, candy canes are not a thing in some European countries and while we urged our Italian and French colleagues to try them, the “toothpaste” taste was not enjoyed by all.
When the submersible returned, so did the outfits, and Alvin was heroically rescued by our resident elf. These elves work hard, he kept the entire outfit on even when swimming. To make this recovery even more memorable, Vanessa Jimenez (WWU) was able to ride the small zodiac boat used to return the swimmers and attach the line that tows Alvin into recovery position.
Alvin Christmas recovery. Top left: Vanessa Jimenez after riding the zodiac. Photo by Shawn Arellano. Other photos by Vanessa Jimenez.
Once the recovery was complete, we all headed to Christmas dinner, usually a very important time for this holiday. We were not let down. Yet again, our amazing chefs had put together a feast! One filled with Christmas specials from all over including roast turkey, green bean casserole, empanadas, and many desserts like rice pudding and apple pie. In the fridge were a plethora of egg nog options to drink. While we ate and talked about our unusual Christmas, the Alvin team each handed us a present, a letter with an Alvin sticker inside, which were highly coveted.
Ugly sweater contest winners, left to right: Matt Skorina, Lauren Dykman, Randy Holt.
After dinner and our science meeting, the festivities began. The ugly sweater contest that Dr. Dykman (WHOI) had planned, was happening in the galley. While Rockin’ Around the Christmas Tree played, each contest cat walked through the entrance, did a twirl in the middle of the room, and exited into the library. Targeting different predetermined categories, some put on a performance. Once all the contestants had walked, our judges discussed intensely. The categories were: most creative, most ocean-inspired, and ugliest. Our winners were clear. Matt Skorina (Alvin) won most creative with his sweater crocheted from climbing rope and ship line. Dr. Dykman won most ocean-inspired, with her sandwich sewn sweater, and Randy Holt (Alvin) won ugliest, with a bobblehead elf sweater.
To end our day, Matt and Benen from the Alvin team decided to whip up something special. Using liquid nitrogen, they made ice cream on the aft deck. In both vanilla and chocolate, it turned out more delicious than we had expected. As liquid nitrogen poured over the table, the creamy concoction quickly chilled into ice cream. Some Oreos were poured over that also turned them brittle and caused our mouths to erupt chilled air like breath on a cold day. As we enjoyed our tasty treats, we laughed and shared stories about Christmases past, a perfect end to another holiday at sea.
EPR Biofilms4Larvae project is a multi-institutional NSF grant: OCE-1948580 (Arellano), OCE-1947735 (Mullineaux), OCE-1948623 (Vetriani).
Benen ElShakhs (left) and Matt Skorina (right) make liquid nitrogen ice cream.
Welcome back! While we’ve been mostly focusing on the active, high-density sites, I’d like to offer some context of vents and delve into another part of this cruise, exploring inactive (dead) hydrothermal vents.
An active site (Biovent) and inactive site (Lucky’s Mound)Pyrite from a chunk of sulfide chimney.
We are studying at the East Pacific Rise (EPR), a raised region of the seafloor formed by a spreading center, where tectonic plates are moving away from each other. As these plates are pulled apart, the Earth’s crust is fractured, and magma rises that cool into new seafloor. When this magma touches seawater, it creates hydrothermal fluid and is why hydrothermal vents are common around these spreading centers. This fluid is rich in minerals that precipitate out and are used by bacteria for chemosynthesis. The “black smoker” chimneys are from iron sulfides in the venting water. In the chimneys we’ve collected we’ve found these precipitates, one of them golden pyrite crystals, an iron sulfide mineral. Inactive vents are regions where hydrothermal fluid no longer flows, and what remains are spires and extinct chimneys made of sulfide rocks that were shaped by animals that used to live there. Because of these minerals, hydrothermal vents have been a target for deep-sea mining, a strategy to harvest these mineral-rich crusts. Seafloor mining is a destructive process and disrupts these communities, so many mining companies have shifted towards inactive vents, where animals are not thought to be found. However, I want to show you the work we’re doing at inactive sites at the EPR and how alive they truly are.
The inactive sites we’re focusing on in this cruise are called Lucky’s Mound and Sentry Spire that were discovered by the AUV Sentry in 2019 and 2021 respectively, and explored by ROV Jason on the 2021 cruise RR2102. Members of WHOI Dr. Lauren Mullineaux’s Lab are particularly interested in these sites and have been working with videos and multibeam scans of these sites leading up to this cruise. On the previous cruise, a rock collected from Sentry Spire was covered in a limpet species called Neolepetopsis which grazes on bacterial biofilms at active vents. It’s theorized that there are unique fauna at inactive vents that graze on bacteria from chemosynthetic rock processes rather than from the hydrothermal fluid. Members of the Mullineaux Lab are interested in exploring the food webs and animal communities at these understudied inactive vents.
Exploring Lucky’s Mound
On December 18th and 19th, divers Michael Meneses (WHOI), Dr. Lauren Dykman (WHOI) on AL5134, and Vanessa Jimenez (WWU) and Dr. Stephane Hourdez (CNRS) on AL5135 explored Lucky’s Mound. And Lucky indeed in this mound. When Michael and Lauren landed on the bottom, they landed right next to the elevator and lander platforms that were deployed the night before (which also descended perfectly)! Even when moving the elevator, they hit the jackpot with a heading of 77.7!
These two platforms we deployed are providing different methods of data collection on this dive. The large elevator has two instruments on it that Tanika Ladd (WWU) is using to compare food webs and the influence of primary production from active and inactive sites. The multicolored tubes are niskin bottles that collect water samples from the seafloor when triggered. Tanika Ladd will filter this water back on the ship to assess the “food pool”, essentially what organisms are living in the water that animals could be feeding on. On the other end of this elevator is a McLane plankton pump. This pump filters water at 30 L / min for up to 24 hours and collects swimming organisms onto a 60-micrometer mesh. When returned to the ship, we sorted through the contents, where Tanika is particularly looking for copepods, but we also found some of their larvae called nauplii, and polychaete worms. Copepods are holoplankton, organisms that spend their entire lives as plankton, and can act as a vector transferring this primary production outside of the vent community. With these copepods, Tanika will extract the DNA inside their guts to see what they are eating. Most marine scientists do not like copepods because they are extremely abundant, clogging samples, and for our lab, sometimes eating our precious larvae! Even still, they are very important members of the community.
Elevator platform with niskins and McLane pump at Lucky’s Mound.
A copepod.
A nauplius.
A spionid polychaete.
The MISO camera on the lander and when deployed over a rock covered in limpets.
The smaller lander is being used by Dr. Dykman to assess the grazing rates and behaviors of animals that live on inactive vents. Using a MISO camera mounted on a small tripod that faces downward, she will record 4K video of the grazers, mostly snails and amphipods, lit from a light on the lander. She hopes to explore how these animals move and interact with each other. If they remain in one place, or are very mobile, as well as if they react differently around transitions between substrate types. We only get snapshots of these animals and their behaviors when we dive and collect samples, so having a long video or time lapses will help us discover how these communities function over longer time scales.
After setting up these two landers to collect science, the rest of the dives were focused on exploration and targeted collections. On the last cruise, Lucky’s Mound was only explored on the northern side, so we took the opportunity to further explore the southern side. Thanks to Ayinde Best (WHOI), here we can see the tracks that Alvin took during these dives. Ayinde has been using the ReNav navigation data from Alvin to plot the course our scientists take on every dive. This helps us orient ourselves with our study sites, see where deployments and samples were conducted or collected and improve our records of dives and cruises. During these dives we found many large animals calling these inactive sites home including Boloceroides anemones, crinoids, Galetheid squat lobsters, cusk eels, and sponges. Ayinde is also involved with these inactive sites, spending his summer studying species and feeding strategies of megafauna that live around Sentry Spire. He hopes to collect video transects of Sentry Spire and collect some animals to build on his past work.
Dive track of Alvin Dive 5134.
Dive track of Alvin Dive 5135
While exploring Lucky’s Mound, sulfide and basalt rock samples were taken, and opportunistic use of Alvin’s slurp hose to collect animals around this site. We try to take as little as possible, since these inactive vents have no more active precipitation and are permanently impacted. With these animals, Michael Meneses (WHOI) plans to dissect and remove their guts to look at what they’re eating. The rocks will also be used to assess the bacterial community through transcriptomics, cell counts, and imaging the biofilms. Back on the ship he sorted through the rocks with assistance from many other scientists on board including Susan Mills (WHOI) and Dr. Stephane Hourdez (CNRS), whose taxonomic expertise at these sites are unparalleled, and already found some interesting discoveries. Hidden amongst the rocks were polychaetes, aplacophorans, slit-limpets, and snails, some potentially new to science. These might be members of a unique community only found at inactive vents. We’re very excited to delve into these samples further.
Photos taken by Michael Meneses (WHOI).
The last way we were studying these sites was through the use of a spot-sensing probe developed by Dr. Nadine LeBris (Sorbonne University). This handheld instrument allows for measurements of pH (acidity), eH (redox potential), sulfide measurements, and temperature at specific spots. For this cruise she has also developed an auto-sensor, that can be deployed within our animal regions and takes measurements every minute.
Dr. Nadine LeBris’ spot sensor grasped by DSV Alvin.
This allows us to read the chemical conditions these animals experience in situ, how they might be manipulating the chemistry of the water and relate animal behaviors to chemical changes over time. Sometimes she attaches a camera that allows us to view exactly where the sensor is measuring and has even placed one inside of a tubeworm before! Using the spot-sensor at these inactive sites has shown us that there are no temperature anomalies near the chimneys and rocks compared to the surrounding seawater, sitting around 2C, when at active vents these temperatures have been measured up to 325C during this cruise. Interestingly, we did see a change in the pH of the water when collecting a rock sample, that the sulfides in the released sediment impacted the seawater and made it more acidic.
Overall, there’s a lot more work that needs to be done at these inactive vents. While the active vents host charismatic and highly adapted animals, we’ve only begun to discover and understand the animal communities at these inactive sites. Hydrothermal vents are inherently ephemeral systems, meaning they exist on relatively short time scales. A change in lava flow or geological movements can cause a vent to stop and the community will shift. Active vents will become inactive sites so we’re curious about how this transition occurs and what the stable communities look like. They may be inactive in terms of the geology and chemistry, but they are certainly still active in terms of the animals that live there.
Next time we’ll dive into the microbes that convert these chemicals into biomass and make these communities possible.
While this happened a week ago, I wanted to take you all on a journey with me to the deep, as I had the privilege to dive with Alvin last week. This post is longer than usual (~20min read). If pictures and videos are more your thing, the story is told through them too!
Pre-Dive
The dive day starts the night before. The first thing each diver must do is pack their bag for a whole day under the surface. In a blue crate in the Alvin hanger, we fill a pillowcase with all the essentials – a pen, a clipboard with notes on our science objectives, navigation targets, and reference images, and 100% natural fiber clothes. We aren’t allowed to bring in any electronics unless they’ve been properly tested, but it’s nice to leave the phone behind. Since Alvin is not temperature controlled, it’s best to pack a sweatshirt and a hat, many of us have red “Cousteau” hats made by loved ones (thanks mom!), but start in the sub with pants and a light t-shirt due to the tropical heat.
In the morning I went into the main lab, first needing to attach Dan Fornari’s MISO camera to the brow of the sub, as I’ve done for every dive. This camera allows us to take 5.3k images every 5 seconds during the entire dive. After fulfilling my duty, I went up to the galley and joined the rest of the science team in getting a full belly for the day ahead. While some try to limit the amount of food and water they consume before spending 8 hours in a 2-meter diameter sphere, fearful of needing to use the bathroom, it’s better to just be hydrated and full. If you need to use the pee bottles in the sub, that’s what they’re there for. We all moseyed to the aft deck where the Alvin team was finishing up preparations: removing the covers on the windows, securing the basket, and checking systems. I stand next to my science observer partner, Lauren Dykman (LD), and our pilot, Bruce Strickrott, and chat with our fellow scientists about the dive ahead, and our excitement. Alvin is wheeled out under the A-frame, a bridge swings out from the staircase and onto Alvin. The Alvin Launch Coordinator calls for the pilot, to begin checking the interior systems, and Lauren and I wait in anticipation, and of course taking a few pictures together in front of the sub. The call for observers signals us to make our way inside. We climb the staircase, turn around, give a wave, take off our shoes, and climb into the submersible.
Lauren Dykman (WHOI) and Dexter Davis (WWU) get ready for their dive, AL-5126.
View outside the porthole as Alvin enters the water.LD and Dexter wearing matching red hats inside the sphere.
Inside, I move to the starboard (right) side, and LD to the port (left) side. Memory foam cushions with blankets on top welcome us, along with iPads for controlling the camera system, small handheld cameras, and our pillowcase day-bags. We exchange animated glances as Bruce finishes up the necessary checks, and the hatch seals shut. Here we go! Alvin is lifted into the air, gently shaking the sub, and is lifted over the water. A loose drawer swings open, and I hold it shut as Bruce yells at it to behave. The sub lowers into the water, feeling akin to the top of a rollercoaster, and bubbles fill our viewports as we make splashdown. As the bubbles clear, we see Alvin divers releasing the basket lines, and disconnecting the main and tow lines above. With the go ahead from the team, we begin our descent. Bruce starts a playlist, and we watch as the light blue ocean turns green, then a dark blue, into black. With a 2500m descent to the bottom, we’ve got nearly an hour and a half before we see the seafloor. LD and I go over the dive plan, familiarize ourselves with the camera and data logging system, while Bruce relays our depth and tells us stories of dives and adventures past. The ocean outside our viewports is not so dark though. Flashes of bioluminescent organisms shine blue and green. A firework show as they disappear out of view. We excitedly shout out the largest jellyfish and siphonophores we see and scan the darkness for new creatures.
Reaching the Seafloor
Then, we see it! Not the seafloor first, but the bright yellow lander platform we launched the night before, with our plankton pump and niskin bottle water samplers. It blinks in the distance and the seafloor comes into view. Made up of hardened lava flows and sharp fragments of volcanic glass, it glistens in the sub’s lights. We approach the lander, move some weights around, and pick it up with Alvin’s manipulator arms to move it to our study sight. As we head east, I trace the lava flows that show a clear direction of motion, picturing the molten formation. Maybe it was from the eruption at this site in 2006. We begin to see some formations on the horizon in front of us: small mountains, and cliffs. As we get closer the structures change into more biological shapes. Groups of Bathymodiolin mussels, and massive clusters of Riftia tube worms begin to surround us as we approach our target site for this dive, Tica, it’s called. We place down the elevator, pull the tabs of the niskin bottles, collecting samples of water from the site, hoping to capture free-living bacteria, and Bruce calls for a break.
The lander with a plankton pump and colored niskin water samplers.The fragmented seafloor.
I reach behind our CO2 scrubber and pull out individual boxes labeled for each of us. Inside, our wonderful cook Susan has prepared us each two sandwiches. Bruce excitedly pulls out his peanut butter and honey sandwich, proclaiming to me and LD how it’s the best kind of sandwich for deep sea adventures, with bread perfectly saturated with the honey. We laugh and observe the incredible ecosystem we’re merely inches from as we refuel. With squat lobsters, eelpouts, barnacles, and small snails crawling around the dominating tubeworms and mussels, there’s so much to watch, it’s so alive down here. Then, Bruce notices something else. A tiny octopus, called Vulcanoctopus hydrothermalis, a hydrothermal, volcanic octopus. This small, white Cephalopod crawls around the rocks as Bruce lines up my camera to capture a 4K video. Nancy, we called it, sets their sights on a gelatinous creature near the edge. Nancy attempts to grab it, but it’s a swimming sea cucumber that expertly thrashes away and is carried by the current. Nancy, defeated, retreats to a hole, they’ll try again later.
A hydrothermal octopus, Vulcanoctopus hydrothermalis chases a swimming sea cucumber.
The Science Begins
The suspension zone, one of three biotic zones at Tica, with tall tube traps and paired sandwich deployments.
Unlike Nancy, we were successful in our consumption, and it was time to do what we came down here to do, to deploy science equipment so we can study these bizarre habitats. Bruce flies the sub over to the first of our three biotic zones, the suspension zone, a cliff where we had deployed pursed “sandwiches” on a previous cruise, and tube traps on a previous dive. On the brink of this hydrothermal community, less impacted by the warm, nutrient rich hydrothermal fluid, there are fewer organisms. Serpulid tubeworms and squat lobsters litter the rocks and some jump away as we approach the cliff side. Our first objective was to open these purses and redeploy the sandwiches that are inside. Bruce picks them up to move them closer to the tube traps we want to deploy next to, but on the last one, it slips, and tumbles down the cliff. We’ll try to get it later. Bruce uses both arms to grab the purse handles and pull the Velcro apart, revealing a sandwich that’s hopefully developed a bacterial biofilm. He delicately grabs the loop, and places it next to a tube trap.
During each deployment, LD and I keep track of the sample ID so we know what’s down here, and the history of them when we analyze them later. While she writes down the coordinates, heading, and ID down on a written data sheet, I update our digital data logging system, SeaLog. With each unpursed sandwich, Bruce reaches into a box on Alvin’s front basket and adds a freshly built sandwich next to it. We are creating clusters of two sandwiches and a tube trap, hoping to identify the impacts of biofilms on larval settlement, and the larval supply in these different zones. For robust science, we do four sets at each zone.
We decide to find the purse we dropped earlier before we move on. We have time, but it’s not going as we had hoped. We spot where the purse had fallen, down into a gorge. We circle around into the right position, where LD and I act as Bruce’s eyes out our side viewports, calling out the distance to rocks and animals, careful to not hit anything. As we descend, we realized that this is the heart of the East Pacific Rise. In the middle of two diverging tectonic plates, we are at the lowest part of Tica. Outside my viewport, I’m face to face with the seafloor, LD has a cliff face. We are barely able to fit in here. Towering above us is a pillar of sulfide rocks, with Alvinellid tubeworms popping in and out of their tubes. In the background are walls of Riftia and mussels, with eelpouts snaking in and out of view. I think about how much we can see from the submersible, but that this ecosystem is usually in complete darkness. I start to think about how different this ecosystem is from ours, how incredible it is that we can visit this harsh environment that humans were never adapted to see. Questions swirl in my mind. Why do these eelpouts even have eyes? Do they see differently? How do these animals interact with each other and what do their lives look like?
The lowest part of Tica, where a purse deployment was dropped.Eelpouts swim above Riftia worms next to a sulfide spire.
Bruce finds and recovers the purse. We return to the cliffside and attempt to open it. We run into an issue, however. The purse handles rip off, without opening the Velcro. Luckily, Bruce and our team anticipated this issue and brought Alvin weapons! There were two knives attach to metal T-rods, easy for Alvin to grab, that we could slice open the purses with. He grabs the first knife, but it shatters as it hits the side of the basket. Darn. He grabs the second knife, and woop! It slips right out of the claw and falls under the basket. We back up to try and see it, but it’s rolled off the cliff as well… I guess we move to plan B. It was time for Plan Bruce. Grab the metal t-rod and shove it through the purse. After a little struggle, the purse is ripped to shreds, and the sandwich inside is recovered unharmed. Good thing we have more purses and even when ripped, we can recover what we need from them. We deploy the final sandwiches and begin moving to the next site. As we leave the suspension zone, we look for the dropped knife. We spot it, but it’s just too far out of reach to recover safely, so we turn around and head for the next biotic zone, the mussel zone.
“Hobo Spire” – a sulfide pillar with Paralvinellid and Alvinellid tube worms.An Alvinellid is attacked by a Paralvinellid tubeworm.
This area was more challenging to get into. On the port side, LD faced a large wall of Riftia tubeworms, actually where our third biotic zone is, and on the starboard side I had a sulfide spire, which we nicknamed “Hobo Spire” for Dan Fornari’s HOBO data logger measuring it. It’s nearly 4 meters tall, but very narrow so we don’t want to hit it and knock it over. There was one set of sandwiches and tube trap already deployed here, and two purses that had previously had their handles fall off, hence why we had the knives originally, and one purse that had gone missing from when we had deployed them in 2021. We nestled next to the spire where I scanned it up and down, mesmerized by the Tevnia tubeworms at the base, and the shimmering diffuse hydrothermal fluid, aware of the heat of the water. As Bruce opened the purses with the same T-rod method, LD and I traded using a handheld camera to take photos of each other and the habitat we were within. I captured a moment where an Alvinellid worm was attacked by a Paralvinellid tubeworm, perhaps a territorial display, or perhaps something more sexual. These animals are thought to be the most thermally resistant animal on the planet, existing at the heat limit of when the mitochondria starts to break down.
A map created by Bruce Strickrott of the Tica site.
Unfortunately, while unpursing, one of the sandwiches inside had broken, but impressively, Bruce picked up the plates delicately as if they were made of porcelain and put them in a stack so we could still use them. These were certainly not the easiest deployments for two robotic arms to work with. Still, Bruce worked expertly. We then shifted to try and find the last purse which we couldn’t find from where we had parked Alvin, so we decided to try to approach from the other side. We backed out from between the wall and the spire and did a large, rising circle to get around the difficult bathymetry of this site. Since 2021, Tica had changed tremendously. Not only were there far more animals than last time, but new sulfide spires had popped out of the ground, making navigating even more challenging. Others had referenced it as a forest of Riftia and sulfide spires. Even still, Bruce knew exactly where he was going, pointing out landmarks like “Tica Prime”, a huge sulfide pillar with a colony of tubeworms jutting off the side, or “Bishop Spire” that looked like the bishop chess piece. As we circled around, LD and I commented on the topography of this site, there was incredible depth to this site that pictures and videos can’t quite translate. From the sub you can see levels below and cliffs far above. As we say this the sub jerks as we bumps a rockface that we couldn’t see below us, reminding us to be careful. We tried to get to the backside of the mussel zone, approaching from the north side, but we didn’t see the sandwich and didn’t dare to get too close to the spiky seafloor.
“Bishop Spire”
“Wall of worms” / “False Wall”
“Tica Prime”
We decided to finish up what we could and stopped at the Riftia zone on the way back to the mussel zone, since they were right next to each other. While we had also lost two purses here, the Riftia had grown so much we assumed they had grown over them and did not want to crush and tear through the animals to find them. We assumed that this was the same fate the mussel zone purse had faced. Instead, we just deployed the final two paired sandwiches with no problem next to the tube traps we had deployed on an earlier dive. Using Dan Fornari’s MISO camera photos, and a Python coding script LD had made, we made a little timelapse of how those deployments looked.
Timelapse of sandwich deployments at the Riftia biotic zone using LD’s Python code and Dan Fornari’s MISO Camera.
Finally, we returned to the mussel zone, squeezing next to the “Hobo Spire” once more, and deployed our final paired sandwich and one more tube trap. Now we had completed the deployments for all the zones at this site. We will leave these down here for nearly two weeks and then we will recover all of them before we leave the EPR at the end of the cruise. Feeling accomplished, and with drawn maps of all our deployments and the main objectives complete, LD and I informed Bruce we could now move onto opportunistic, ancillary objectives. We wanted to collect some mussels, and potentially some sulfides with Alvinellids that one of the Principal Investigators (PI) on this project and cruise, Costantino Vetriani and his lab could use for isolating bacteria from these sites and grow them. Unfortunately, while we were looking for a collection site, we realized we were running low on battery, and it was time to return to the surface. Had it really been nearly 8 hours already?
Reluctant to leave this bizarre and beautiful world we were exploring; we began heading west. When Alvin ascends, stacks of weights must be dropped, so we always try to leave the study site and avoid impacting the community when doing so. As we leave Tica, Bruce exclaims and points out the window. There we see a giant sea anemone called Boloceroides daphnae, that can have a diameter up to 2 meters. These are rarely seen, and this large purple one had tentacles that trailed in the current for many more meters. We admired it but quickly changed focus when we saw a large, coiled line that was unmarked. If we hadn’t seen it, future dives could be at risk of entanglement, so we called up to top lab (the Alvin team on the ship end of the communications), and marked down the coordinates.
Photo of Boloceroides daphnae in the bottom left of image.
We then left the site and got ready to ascend. LD called up to top lab to Costa and relayed our science report – what objectives we had completed, and if we were bringing up any samples that our team should be ready to receive. We had purses, but no live animals and no suction samples, so there wasn’t much to recover when we got back on deck. It was incredible that we were able to communicate so easily to the ship 2500 meters above us. Bruce then confirmed if we were clear to leave bottom, and he offered me the opportunity to be the one to drop the weights. I stood up, for the first time in 8 hours, primed the release, and dropped one set of weights on the starboard side, and the on the port side, and just like that we began to ascend.
Returning to the Surface
With another hour and half ascent time, we could just relax, listen to some music, and talk about the dive. We ate our second sandwiches, turkey and cheese this time, ate some molasses cookies we snuck on, and still wondered what was for dinner. During all this free time, it was a good time to take care of all our bodily needs including using the restroom. While I had gone earlier, Bruce and LD grabbed a bottle each, accommodating for all genders, and put up a privacy curtain while Bruce searched for the “perfect song” to hide the sounds. I intensely stared out the window while business was taken care of, and then we all came back together. After spending a whole day together in ~34m2, awkwardly bumping one another and accidentally playing footsie, we were very comfortable with each other. During the rest of the ascent Bruce told us about his history as a pilot, some stories of other dives, and we talked about vacationing in Costa Rica.
(Above): Alvin track map during dive AL5126, with lower elevations in yellow-green. We started on the west side. (Left): Notes taken during the dive, with maps of deployment and their IDs. These are used to write dive reports to use in a cruise report at the end of the research expedition.
As we returned to the surface, watching black turn to dark blue, to green, to light blue, we were welcomed back by the Alvin swimmers. They secured the basket, attached the sea anchor that helped us control our surface speeds, and helped direct Alvin towards the back of the ship. As we bobbled on the surface, I started to feel a little bit seasick, with more light than we’d had in a while, and being in a lower oxygen environment. I was eager to get out of the sub, but still enjoying every moment being inside. Once we reached the A-frame at the stern of the ship, we were picked up and lowered back onto the deck, into Alvin’s “sled” that moved it in and out of the hanger. We waited as the Alvin team secured us and started assessing the sub for any damages. (We may or may not have gotten a scratch on the side when we were circling the mussel zone.) While the sub warmed up from being out of the water, the sphere began to condensate, a light tropical rain came down from above. Then, we heard the hatch open, fresh air flowed in, and they lowered the ladder for us to climb out. First went LD, then I climbed out. We waved and exclaimed as we walked off the sub to the rest of our team cheering from below, taking pictures and videos of us returning from the depths. I hurriedly put on my shoes, fumbling the laces with everyone watching me, and we climbed down the stairs on our wobbly legs to recount the dive and our successes. Since LD and I had both had Alvin dives before, we didn’t get any surprise buckets of water dumped on us, but this dive was certainly the most spectacular we’d ever seen and it felt just as momentous.
Collecting deployments off Alvin’s basket.
Dexter and LD at sunset.
We watched as the sub rolled in, retrieved our opportunistic science that we didn’t get to from the basket, I brought in the MISO camera, and we all headed to dinner. After dinner we held our regular science meeting, where LD and I reported on the science portions of the dive, and we began getting ready for the next dive. We’re diving everyday for 20 days straight to get all our goals for this cruise done.
I wanted to share with you the experience of one of these dives, to highlight the magic of these expeditions into the depths. See you next time!
Hi everyone! Now that I have my graduate school applications in, I’ll be posting more frequently.
I keep talking about the Alvin submersible, but how does it work? I thought it’d be helpful to outline the vehicle and team that is making all this science possible. It’s a sophisticated machine with a lot of thought put into safety and utility for deep-sea exploration, so I will do my best to summarize it without going into too much detail.
Meet the Submersible:
Alvin is an iconic human-occupied, Deep Submergence Vehicle (DSV) operated out of Woods Hole Institute of Oceanography (WHOI) and travels with the R/V Atlantis. This 23-foot submersible powered by two 60-cell lead acid batteries is able to take a pilot and two science observers up to 6,500 meters deep, a recent upgrade made in 2021, surpassing the previous limit of 4,500 meters. The outer shell is made of syntactic foam, a buoyant, yet sturdy material, and the scientists dive within a 2.815 inch thick, 2-meter diameter titanium sphere that resists the 10,000 lbs/in2 pressure at 6,500 m and the corrosiveness of seawater. The sphere has five portholes with thick acrylic windows and a top plug shaped like cones that seal better with higher pressure. With 7 thrusters and 2 ballast systems, the submersible is able to move in any direction and control its buoyancy, how it floats in water, along with a mercury trim system that allows the sub to pitch back and forth. Alvin also has 3 sets of weights (~350lbs each) that can be dropped on either side that control descent and ascent rates.
Alvin is well equipped for all our science needs. With 2 manipulator arms controlled by the pilot, they can grab science instruments, tools like scoops and suction hoses, and collect samples with joints similar to human arms. On the front of the sub is a platform, called the “basket”, that can hold up to 400lbs where containers and instruments can be attached for use in the deep. These arms can open these boxes and undo elastic or bungee cords to secure collections, grab temperature probes and water samplers, or open purses that our sandwiches are in for this cruise. Alvin also hosts a number of cameras that allow us to record our deployments, survey our sites, identify organisms, and take videos we can use to trace the history of sites and further analyze in the future. A 4K resolution camera and one 1080p PATZ camera on each side offer pan and tilt capabilities with zoom, focus, and ISO manipulation for the science observers. The pilot also makes use of a pilot cam above the central window, one under the sub and one pointing aft (backwards) to orient themselves during operations. Of course, the sub also has lights on the brow above the windows, on the sides, below, and behind to be able to see in the vast darkness of the seafloor.
What most of you are wondering is probably the safety of the submersible. There are rigorous checks before and after each dive, and many safety measures in place in case of an emergency. With 12 tanks of pure oxygen inside, and CO2 scrubbers, 3 people could survive 3 days at the seafloor, but operations are limited to daylight, so dives do not typically last longer than 9 hours (8-5pm). Inside the sphere are oxygen sensors and leak detectors that would catch any causes for concern. The position of the sub is tracked from the ship, and multiple communications systems allow the pilot to relay information to another member of the team throughout the entire dive. In cases of emergency, whether Alvin gets stuck, or needs to emergency ascent, extra weight stacks can be dropped, but most of the pieces of Alvin that stick out can be dropped, including the basket, 5 of the 7 thrusters, and the arms. The extensive training pilots go through before they can solo dive and the above measures made me feel completely safe within the submersible.
Meet the Team:
Working in the deep-sea in challenging, and it can be a brutal place. Thankfully we have an excellent team of engineers on board that travel with Alvin, solving any issues encountered during, before, or after a dive. They work diligently and put up with our last-minute requests as we manipulate the basket and change science objectives overnight. Without their hard work, none of our science objectives would be achievable.
Left to right: Benen Elshakhs, Nick Osadcia, Nick Ellis, John Dymek, Kaitlyn Beardshear, Rick Sanger, Matt Skorina, Bruce Strickrott, Randy Holt.
Benen Elshakhs – Mechanical Technician. The newest member of the Alvin team, Benen from Storrs, Connecticut, joined the team in June of 2022 after working as an integration engineer for an aerospace company in California. He received a B.S. In Mechanical Engineering from Worcester Polytechnic Institute.
Nick Osadcia – Mechanical Section Lead / Pilot in Training (PIT). From Plymouth, Massachusetts, joined the team in August of 2018 after volunteering with Alvin since 2016. He first received an Associate’s in Environmental Studies from Cape Cod Community College, and then a B.S. in Mechanical Engineering from University of Massachusetts. He met the team when he was working with Julie Huber at the Marine Biological Laboratory. He’s currently finishing his PIT training and will be the next Alvin pilot.
Nick Ellis – Mechanical Technician. Nick has been involved with Alvin since 2018, with a history of robotics in high school, he interned with Alvin under the MATE program and joined the team during the overhaul in 2020 assisting in the new design work. He received a B.S. in Mechanical Engineering from Santa Clara.
John Dymek – Mechanical Technician. Joining the team in March of 2021, John came from working with warehouse robots in Boston, Massachusetts. While receiving his B.S. in Mechanical Engineering from Northeastern University, he participated in coop programs focused on hands-on learning with hydro-electric vehicles and biomed applications. Joining the team after a friend at WHOI recommended it to him, he says it would be difficult to return to a desk job.
Kaitlyn Beardshear – Electrical Technician / Pilot in Training (PIT). From Monterey Bay, California, Kaitlyn was introduced to working with Alvin through the MATE program. Fun fact, the Arellano Lab went to sea with Kaitlyn as an intern and has now seen her graduate to the newest Alvin PIT on our last cruise. She received a B.S. in marine science from California State University Monterey Bay and afterwards began working with marine robotics, autonomous and remote operated vehicles, then returned to pursue an Associate’s in Mechanical Engineering. She is currently studying for a Master’s in Mechanical Engineering from Arizona State while she works at sea.
Rick Sanger – Electrical Section Lead / Alvin Pilot. Rick joined the Alvin team in 2011 but worked with WHOI for 25 years before as an engineer helping biologists designing instruments. Rick is the most knowledgeable about the systems of Alvin, having helped develop most of them! As the newest pilot, Rick now works with the scientists on board to conduct research safely and efficiently in the deep sea. He has currently done around 15 solo pilot dives and has a new-pilot party on the way.
Matt Skorina – Electrical Technician. A local Washingtonian from Walla Walla, WA, Matt joined the Alvin team in April of 2022. After graduating with a B.S. in Electrical Engineering from the Rose-Hulman Institute of Technology, he met a WHOI graduate student that inspired him to apply to work with Alvin and get involved with science support. Matt can often be seen sporting a fantastic galaxy romper when taking on the swimmer role for deployments and recoveries.
Bruce Strickrott – Alvin Program Manager / Senior Pilot. A member of the Alvin team since 1996, Bruce has been instrumental to Alvin’s success and the success of science in the deep-sea for decades. With over 380 solo dives, Bruce is in the running for the most Alvin dives of any pilot. Graduating from Florida Atlantic University with a degree in Ocean Engineering, he enjoys using technology to alter people’s perceptions of the world. As a pilot he cracks jokes, tells entertaining stories, and a phenomenal playlist to make every dive memorable, whether a scientist’s first, or one of many. Most importantly, he also exhibits a mastery of the submersible, knowledgeable about the exact size to get into the smallest of spaces and makes using the manipulator arms look like extensions of himself.
Randy Holt – Expedition Leader. Joining the team in January of 2021, Randy acts as the coordinator between the ship, the scientists, and the Alvin crew to complete the objectives of the research cruise. A Western Washington University alumnus, Randy received a B.S. in Industrial Technology where he worked on an engineering project designing a human-powered wet submersible. Randy has extensive experience with submersibles from working with Ocean Gate in Seattle, and as a contractor sub pilot.
Justin Smith – Alvin Data Specialist. Another Washington native, Justin grew up in Seattle, WA. While Justin has extensive ship-going experience, this is his first cruise working closely with Alvin as their data coordinator. Justin is crucial to the scientists assisting with transferring the photos, videos, and navigation data from Alvin after every dive. He has worked closely with scientists acting as the marine technician for years on the for the Kilo Moana, University of Hawaii’s research vessel, the same university where he received a B.S. in Environmental Science.
Scientists Meet Alvin:
For many of us, this is our first time sailing with Alvin. Never imagining being able to visit the deep-sea, we’re hopeful for a chance to dive with the submersible and see first-hand these unique habitats. Luckily on this cruise we have a lot of science to deploy and recover, planning around 20 dives. With two scientists per dive, everyone on board should get the chance to experience the once-in-a-lifetime feeling of visiting the seafloor. Many of the students in the different labs on board have projects focusing on these vents, so they are eager to see their sites, organisms, and potentially explore new locations for future plans. During our science meetings, Shawn will announce who is diving the next day, each student hoping that it’s them.
There are a few rituals that our scientists participate, voluntarily, in during a dive. After you walk up the A-frame to the bridge leading you to the sub, our scientists give a wave to the rest of the group, take of their shoes, and enter the sub. After 8 hours crammed in the small sphere, they give another wave as they stretch their legs once climbed out of the sub to our cheers. The most fun comes once the scientist returns to the group. We listen to them recount their dive, the new experiences they’ve had, and then we ask them to sit down. Then, with consent, usually a fellow lab member or advisor who has dived before, will dump a bucket of the coldest water they could make on them, welcoming the newest Alvin aquanauts. It’s always important to remove your shoes and glasses before this! We share laughs and congratulations and then urge them to dry off before our science meeting.
Visiting the seafloor is a life-changing experience for anyone, but especially to us that have dedicated ourselves to studying and protecting the ocean. We want to share these experiences with our friends and family but wish you could all go down with us. Follow along as we continue to explore these exciting vent habitats on this cruise, and the science behind our research.
New Alvin Aquanaut Olivia CannonNew Alvin Aquanaut Tanika Ladd
The sandwich deli in action.Top: Settlement sandwiches.
Bottom: Biofilm sliders.
After four days transiting across the Pacific, we’ve finally reached the East Pacific Rise. While the 80°F weather and open ocean call for sunbathing all day, the science began before we even reached our study sites. In the main lab the workshop was up and running, with many experiments to build that were to be deployed soon after arriving. The elves were hard at work on these seafloor gifts for the holiday season, creating settlement “sandwiches”, biofilm “sliders”, and larval traps. These will be left on the seafloor to develop bacterial biofilms and assess the larval supply at these hydrothermal vents. Don’t worry, we will be bringing all these back on board before we leave (or picking them up on the next cruise). In total we made nearly 100 sandwiches, and 24 sliders and larval traps.
When working on the seafloor and with submersibles, we must account for buoyancy, ease of deployment, and ease of identification underwater. We have to make sure our experiments don’t float away, tangle together, and are easy to pick up with a robotic claw. To do this, many of these instruments have loops of polypropylene rope that suspend a large circle above them, with bright colored duct tape, and weights on the bottom. Then, we have to make sure that they can all fit on the submersible and actually be deployed. In addition to these deployments, we have a multitude of instruments that we will be using on these dives to sample water, bacteria, temperature, among other things. As these posts continue, I’ll try to highlight the different techniques and tools we are using on this project.
Since we have so many objectives and limited space on the submersible that meant we had a lot of planning to do. In the library, the chief scientist (Shawn Arellano), hosts science meetings where we’ve been having these discussions. In the beginning we introduced our projects to each other, familiarizing ourselves and reminding the teams of the goals for the cruise and for the individual teams. We discussed dive plans, who was diving, the objectives of the early dives, what instruments were to be on the submersible, and the various teams for recovery and deployment of the submersible. We were also joined by the Alvin team for logistics of how to use each of our instruments, where our study sites were, how to organize the submersible basket, and schedule trainings for the sub operations. Importantly we also talked about contingency plans for a potential eruption at the East Pacific Rise. This hydrothermal vent site is volatile, and an eruption could even occur while we are out here, so we need to be prepared incase our study site has completely changed.
Tube Trap Deployments
Map by Jyun-Nai Wu at Scripps Institute of Oceanography, PhD student of Dr. Ross Parnell-Turner.
It all came down to today. This morning Shawn went with Alvin pilots Bruce Strickrott and Rick Sanger on an exploration dive across our sites. At 0800 the submersible lifted off the deck, swung out with the A-frame, dipped into the water, and started the hour and a half descent to the vents 2,500m below. In the main lab we have limited communications with the sub, so we all waited in suspense of what was being seen below. Alvin operations occur during daylight hours, coming up around dinner time, so we wouldn’t know until 1700 (5pm), unless the dive was aborted early. We held our breath, but went about our days as normal, and getting ready to deploy another of our instruments, a McLane pump for collecting larvae. The dive seemed to go well, with the sub recovery planned as usual. After retrieving Alvin from the surface, we huddled on the aft deck, watching the aquanauts climb out of the vehicle and down the stairs. Shawn approached the group and began recounting her dive.
Good news! There was not an eruption and the animal communities seemed to be thriving! The last cruise for this project was in March of 2021, so after nearly two years, these sites were expected to drastically change. At the bottom, the sub had cautiously approached the seafloor, in case of erupting lava flows or plumes of venting smoke. With the coast clear, they headed towards Tica, one of our target sites. As the vent field came into view, huge groups of Riftia tubeworms (one of the largest benthic invertebrates in the deep sea, up to 9ft tall!) covered chimneys, with groups of Bathymodiolin mussels surrounding them. Crawling all over these animals were Galetheid squat lobsters, Cyanograea crabs, limpets, and Zoarcid (eelpout) fish. The densities of these organisms were much higher than the last time we were here, indicating a healthy and growing community. Surprisingly, there were also gooseneck barnacles and anemones that weren’t there before, suggesting these were late-succession communities.
Photos credit to Dan Fornari’s MISO Cameras.
As the dive went on, heading towards Rifta Mound (not labeled, but near P vent on the map) our team scanned for our deployments from the last cruise, sandwiches that had been left in mesh “purses” to develop bacterial biofilms. Much of the site geology had changed as much as the biology had, with new spires creating a difficult bathymetry to maneuver, and some new chimneys pumping black smoke into the water. Some of the deployments were easy to find, exactly where we left them, while others had animals grown over them, or they had fallen from their previous location. Some we could not find at all. In our science meeting we discussed our game plan for uncovering and finding these pursed sandwiches, we call them “pursewiches”, and deploying new sandwiches next to them, among other deployments and experiments. We’re planning around 20 total dives on this cruise to get all our objectives complete, so every science team member should be getting to experience these sites within the submersible. Tomorrow we’ll begin unpursing these sandwiches, starting at Tica.
Welcome to the first post of the East Pacific Rise Biofilms Project Research Blog!
Today we left Puntarenas, Costa Rica for a 4-day transit through the Pacific Ocean heading towards the East Pacific Rise. We will be at sea for the entire month of December, including Christmas, Chanukkah, and New Year’s, so please reach out to us as our family and friends! We return to port on January 1st, welcoming the new year with new deep-sea discoveries.
What Are We Researching
On this cruise we will be studying the role bacterial biofilms play in larval settlement at hydrothermal vents along the East Pacific Rise (EPR) at 9°50’N. On board the R/V Atlantis, we will work closely with the human occupied submersible, Alvin, to travel to depths around 2,500 meters and deploy experiments, recover past deployments and collect samples. In hydrothermal vent communities, bacteria are the basis of life, converting hydrothermal vent fluid into biomass that can be utilized by animals living near these ecosystems through symbiosis or direct consumption. These bacteria can exist as free-living cells in the water column or attached to surfaces as biofilms. Bacterial biofilms incorporate the chemistry and temperature variability of the environment that could predict habitat suitability for settling larvae. Essentially these bacterial communities might communicate to larvae that this is the right place for them to land and develop.
To explore the role bacteria play in this settlement process we will be deploying short-term settlement experiments called “sandwiches”, 6 polycarbonate plates stacked together. We will deploy them in a mesh “purse” that will allow bacteria to grow a film on the plates without letting larvae and animals in. Later we will uncover them and see what larvae and other animals attach to the sandwiches. Each filmed sandwich will be paired with a fresh sandwich to control the effects of these bacterial films. We will also use a variety of -omics methods to better understand the composition and function of the bacterial communities. Within our study sites we will deploy these sandwiches at three different animal zones: one dominated by Alvinella tubeworms, one dominated by Riftia tubeworms, and a third dominated by Bathymodiolin mussels. These animals exist within distinct zones, constrained by increasing H2S concentration and temperature of the surrounding water.
Who Is Researching
(Right) Scientists from WWU. Left to right: Vanessa Jimenez, Wyatt Heimbichner-Goebel, Dexter Davis, Tanika Ladd, Shawn Arellano. Photo taken by JP Isaacs.
(Left) Scientists from WHOI, SU, and CNRS. Left to right: Stephane Hourdez, Michael Meneses, Ayinde Best, Lauren Mullineaux, Nadine LeBris, Susan Mills, Lauren Dykman. Photo taken by JP Isaacs.
(Right) Scientists from RU and UN. Left to right: Matteo Selci, Martina Cascone, Donato Giovanelli, Costantino Vetriani, Olivia Cannon, Ian Schlegel, Avanthika Bharath. Photo taken by JP Isaacs.
The teams on board come from institutions all over the world with scientists from Western Washington University (Bellingham, WA), Woods Hole Oceanographic Institute (Falmouth, MS), Sorbonne University (Paris, France), CNRS (France), Rutgers University (New Brunswick, NJ), and the University of Naples (Naples, Italy). We will also be working closely with JP Isaacs, and Dena Siedel from the Documentary Film Lab at Rutgers to create a science-in-action documentary film to share the excitement and effort for deep sea research. Coming from all these places meant we had a long journey getting to Puntarenas, with many of these groups having multiple travel days. Once we all arrived in San Jose, we had to take a shuttle an hour and a half through the country until we reached the shores of the Pacific Ocean. For many of us it’s our first time in Costa Rica, one of the most biodiverse places on the planet, so the shuttle ride was filled with excitement scanning the forests for rare, and new animals. Some of us were lucky enough to see a toucan in a tree right off the main road! When we reached Puntarenas, the ship was not docked in port, so we had to take a water taxi to get on the Atlantis. Having to pack for a month at sea, and some vacationing in Costa Rica, we had a lot of bags. Our bags were filled with science equipment, clothes for conducting science comfortably in tropical heat and in the cold rooms on the ship, plus some holiday cheer. Thankfully both the shuttle and the water taxi were able to accommodate our large amount of luggage.
How the Research Begins
While Shawn Arellano and Dexter Davis were reunited to the ship after spending October on the Atlantis, the rest of the team became familiar with the vessel and unpacked into their berthing rooms (after everyone tested negative for COVID). We spent the mobilization days introducing each other, having meetings about science objectives, and planning out and setting up the lab spaces. We checked all our equipment was where we left it before the Atlantis left the U.S., that we had access to salt, fresh, and milliQ water, the cold rooms were set up, and everything unpacked was organized and secured. We set up microscopes, pressure vessels, video equipment, and of course made sure we all paid rent on the first of the month. During set-up we made sure to make this ship a home by putting up some holiday decorations, designating office spaces, started introducing ourselves to the crew members, and catching up on sleep lost during travel. Before we left port, we even helped the cooks on board by loading local fresh fruit, vegetables, pasta, snacks, eggs, and other food items from the side of the ship to the elevator that went to food storage. If they were to cook for us for a month, we were more than happy to help them.
As we set sail at 8 in the morning, we watched as civilization faded, enjoying the warm tropical sun with pelicans and frigate birds overhead, and scanning the water for dolphins and turtles. We are excited for the adventures ahead, the discoveries to be made, and the new family we will be a part of for the next month. During this 4-day transit we will prepare our deployments, get our chemicals ready, solidify our research and dive plans, and adjust to life at sea.
Follow us along on this blog as I share the intricacies of deep-sea research, introduce each of our collaborating teams, and share our findings.
I’ll also be posting to the Arellano Lab Instagram (@larvallab) and twitter (@LarvalLab) and follow #Biofilms4Larvae for more posts.
The Arellano lab is looking for a postdoctoral research associate to work on an NSF-funded collaborative project investigating “The Predictive Nature of Microbial Biofilms for Cuing Larval Settlement at Deep-Sea Hydrothermal Vents.” The postdoc will work with PI Dr. Shawn Arellano and collaborators at Rutgers and Woods Hole Oceanographic using manipulative field experiments at the East Pacific Rise hydrothermal vents to model the habitat and biofilm cues that predict variations in larval settlement. Field experiments will be followed by shipboard tests of hypotheses using field collected larvae, lab developed biofilms, and pressure vessels. Because WWU is a primarily undergraduate institution, there are also opportunities to work with undergrads and MS students, and potentially to teach and participate in pedagogical workshops.
The successful candidate will be a marine ecologist with strong experimental design and quantitative skills, as well as interest or knowledge in larval settlement and hydrothermal vents. Prior seagoing experience is not required but is a plus. The position is a two-year appointment and our first research cruise is winter 2022. Someone who could start by Fall 2021 is preferred.
Position Duties and Responsibilities:
Conducting experiments at sea, managing data, and conducting statistical analyses (50%)
Writing manuscripts for submission to peer-reviewed journals; presenting data at scientific conferences. (25%)
Broader impact activities: mentorship of undergraduates and graduate students and participation in a science-in-action film (15%)
Preparing for research cruises, including ordering, preparing equipment, packing, and shipping (10%)
The successful candidate must be willing and able to conduct research at sea for long periods of time (1-2 months at a time, on at least two research cruises).
