Research Adventures on the 2021 SALT Cruise
The following are journal entries by Michael Gray, an undergraduate research assistant with the Ocean Observing and Modeling Group (OOMG). Michael was aboard the R/V Thompson as part of the Seep Animal Larval Transport (SALT) research project. The cruise went from Woods Hole, MA to Gulfport, MS from 25 May to 21 June 2021. Michael refers to the Remotely Operated Vehicle (ROV) Jason and the Autonomous Underwater Vehicle (AUV) Sentry with SyPRID attachments.
Journal Entry 5/25/2021
Today we departed from Woods Hole Port around 10 am. Even though I was already about three days into my scopolamine patches, the sea sickness began almost immediately! The R/V Thomas G Thompson is definitely quite the vessel- almost as large as a football field and carrying everything needed for 4 weeks with 30+ people AND Jason + his crane AND Sentry.
We boarded the ship Sunday morning and started getting to work right away unpacking and securing materials for the cruise. We have quite the array of microscopes, dozens of containers, and countless other equipment either tied, ratcheted, or taped down. Unfortunately, we did have to sacrifice the ping-pong table to make our larvae sorting station…
Personally, in terms of science, I haven't done much more than work on my personal projects. However, I did get promoted to the weatherman of the team and have been used occasionally to read different plots describing the profiles of the seep sites (stick plots, time series plots of winds and currents, vertical temperature profiles, etc.).
Accommodations definitely exceed expectations (at least for a ship from the 80s). Our berthing is set as 2 to a room and 2 rooms to a bathroom. The bedding is really comfortable for not being an actual mattress and comes with 2 really soft pillows, sheets, a comforter, and a blanket. The bathrooms are simple, just a toilet and a standing shower that has very nice water temperatures. The food…. Wow, the food. So far, the galley has made flank steak, lobster rolls, smoked salmon, chorizo breakfast burritos, orange glazed Cornish game hens, and tons of homemade desserts. I came with intensions of eating really healthy and losing some weight while aboard- no chance of that happening.
We had our first science meeting to let the Jason and Sentry people know what we are doing for this cruise. Now we are all just sleeping, eating, and waiting around for when we reach our first stop: Baltimore Canyon.
Journal Entry 5/26/2021
Today we arrived at our first stop, Baltimore Canyon, at about 7:00 am; 21ish hours after out departure from Woods Hole. It's beautiful to see nothing but the ocean in every direction. Really a site to behold.
This morning (around 8:30) we deployed Sentry at the site. It was really interesting to look over the tech's shoulders and see Sentry fall nowhere near where they intended and not have a single person freak out about it. Of course, it makes sense- it's almost impossible to hit the exact coordinates of their plan so they just throw Sentry down then send a command of where to go before it starts its path. While on the bottom (max depth: 430 m, Sentry stays around 428 m), Sentry is collecting larvae samples using very gentle vacuums (SyPRID samplers) which pull and filter sea water.
While waiting, I got my first experience with something related to physical oceanography! I was able to set up a current tilt meter to replace the first one Jason pulls up from the site. Really simple- just a few tiny edits to a program called Domino that adjusts sampling rates and intervals. Definitely had to stop and remember why the word "Nyquist" popped into my head. The good/bad thing about being at sea is I rely VERY heavily on what I know because I don't have the data allotment to look every little thing up!
After 6 hours of us just hanging out, Sentry is returning to the ship! Upon its return, some of the scientists rushed out and collected the larvae samples from SyPRID as quickly as they could. (While doing so, I got to see a huge pod of dolphins!) These samples were all brought to the sorting area where we looked through them thoroughly to find any larvae under study. Don't ask me which ones they were quite yet, I'm still in the "oh this one looks different than anything else, is this something?" stage of my biology skills.
Jason was expected to deploy around 3:30 pm but encountered some errors in preparation so it was delayed until 6 pm. The plan for the dive includes recovering some lost moorings from the PEACH storm group followed by sampling at depth for the larval dispersion research. We got to go into the Jason van and look at all the controls and displays that the pilot uses. It was really impressive how much they were able to fit into two small shipping containers! Fully equipped with AC too!
Unfortunately, Jason was not ready to dive by the suggested time. While waiting, we have created a 24hr schedule for the science crew to follow. Basically, we are divided into three teams and each works an 8hr shift, then an "optional" 8hr shift (depending on the timing of Jason, Sentry, and CTD dives), and finally 8hrs off. It will be quite a task to reorganize my sleep schedule.
Since Jason was unable to be deployed, we decided to cast a CTD with 18 Niskin bottles to retrieve water samples at various depths. Dr. Arellano has placed me as team lead for casting and recovering the CTDs- which was time well spent! I was captivated by watching the development of the plots of temperature, voltage, florescence, salinity, and many other parameters as the CTD did its thing.
We finally finished sorting at 11:30 pm and are now out of work until Jason deploys which is now expected to be around 6 am. I would typically be on shift from midnight – 8 am but, given that there is nothing to do at the moment, I'm taking the opportunity to catch up on sleep!
Journal Entry 5/27/2021
Once again, Jason has been delayed. Complications with Jason's winch has pushed the launch to this evening. However, we did deploy Sentry for its first dive off-site! Sentry was deployed around 12:30 pm and before then there wasn't really anything to write home about. There is some light in the Jason delay: we all have time to adjust to our newly assigned sleep schedules.
So far, I've been made aware of three methods of data collection for this particular cruise: Sentry's SyPRID vacuums, CDTs, and Jason (Slurp, retrieval of larval traps and tilt meters, collection of mussels, etc.). With Jason out of the picture, this is starting to look like a fairly short cruise in terms of tasks. Hopefully the problem can be fixed and Jason can be deployed at least once per site, otherwise a lot of the projects being conducted by Grad and PhD students aboard will fall vastly short of target samples.
As of now, we're unsure whether or not we're scrapping the Jason dive for this site. If we do find a way to deploy it, we will be hanging around here for another full day then departing for our next stop: Chincoteague. Sentry returned around 11:30 pm so it's back to sorting for tonight!
The weather has been pretty agreeable so far. There's been very few instances of large swells, mostly just a bit of rocking. Let's hope it stays that way as we move south!
Journal Entry 5/28/2021
We were finally able to get Jason in the water! At 4 am, Jason was successfully lowered into the water and began its dive down to Baltimore Canyon. While on the bottom, Jason grabbed (and chipped) the tilt current meter and larval traps that were left during the last spring cruise, scooped up dozens of mussels and carbonate rock, and SLURP-ed many other samples.
I didn't venture into the Jason control room this time around, but I do plan to at least once during the cruise. Nevertheless, there was plenty of excitement for me. One of my individual roles includes retrieving and replacing the tilt current meters at every site. They are pretty cool instruments- each one is a cylinder that stretches a few feet, which is buoyant, and houses a small circuit board that measures the amount of tilt from each of its axis in the water. From there (and after factoring out some vortices) the preprogrammed algorithm determines the speed and direction of the current at the ocean floor. We will be collecting and replacing these at each site and then I get to take the data, plot it, and compare it to the climatology our lab has provided. Baltimore Canyon looks to have been very active over the past year with current speeds a whole order higher than what we've seen!
Whenever we get some free time, we toss in a CTD with an 18 bottle Niskin rosette to collect conductivity, temperature, and depth (along with countless other variables) profiles along with water samples at variable depths. It was a lot of fun, for me at least, to play a little guessing game of where I thought thermoclines were (especially because I was miraculously correct most of the time). Funny how you think you learn nothing in college until you're thrown into the real world! Next stop: Chincoteague.
Journal Entry 5/29/2021
After our 3 hour transit to Chincoteague, we were met with some rather unwelcoming weather. Jason was supposed to dive about 30 min after our arrival, but has gotten delayed. It isn't the end of the world- this gives us time to catch up a bit on our work from the Baltimore Canyon samples.
Personally, I still don't have a great feel for the biology aspect of this study quite yet. Instead, I've spent my time analyzing the CTD and current data that we've gotten from Baltimore Canyon. I find it pretty fun trying to decipher the plots I've made (stick plots and vertical profiles of various variables) with the chief scientist- especially since I can't pull up my class notes on under water currents! But, I think we've more or less been able to figure it out.
The weather is starting to make the majority of the science party a little useless (myself included). We're reaching almost 3 meter swells that really aren't easy on our stomachs. Thankfully, everyone is really understanding and refuse to pressure anyone into working when they aren't feeling great.
Jason did eventually find time between bursts of storms to make it into the water. While I haven’t gotten to go in the van yet, they do display the science camera on monitors throughout the ship so I do get to see all the cool mussel beds!
We ended the day with sorting the samples Jason has gotten us and a CTD cast in the evening. We have another Sentry dive planned before we head out to Blake Ridge.
Journal Entry 5/30/2021
Weather today has been way too crazy to allow Sentry to dive. Instead, we've been working on the Jason samples and whatnot. I have found a new place in the science crew that doesn't involve looking into a microscope (whew!). Being one of the more seasick people, but not to the degree of having to lay down, I got pulled into the mussel measuring and dissection team.
I must say, it is far from the most exciting roles, but it is a lot better than staring at larvae. My team is taking all the mussels retrieved by Jason and taking samples for DNA and isotope analysis. It is REALLY hard to deal with the smell on top of being seasick- samples pulled from 2000 m deep do not bring a pleasant aroma by any means. Nevertheless, we measure each mussel, crack it open, determine its gender by analyzing their gonads for gametes, collect the gills for the research of a scientist not currently on the cruise, and preserve the rest of the mussel in a formalin solution.
This occurred for the first 50 mussels we found. The remaining collected mussels were just measured and sorted based on dimensions… so far we've counted 300 from the Baltimore Canyon samples alone.
We're reaching the time limit for this location but will still try to squeeze in a Sentry dive for as long as we can in the morning if the weather is cooperating.
Journal Entry 5/31/2021
Sentry was able to make it into the water for a limited time- typically Sentry stays down for 8-12 hours and collects 2 SyPRID samples: one throughout the water column and one at the max depth. However, this dive can only be 5 hrs for us to stay on schedule so we will get a single sample from depth. I'm not complaining- that's less sorting for us to do!
While waiting, my team went back to measuring mussels. We finished with a number of over 500 mussels! Apparently, a couple sites from the last cruise didn't collect enough mussels so they made sure to have plenty this time! Hopefully we reached a happy median at Chincoteague!
With the conclusion of mussel measuring, we have processed all of the Baltimore Canyon samples! Now we have a two day transit period where we will be making a couple stops to attempt to retrieve some PEACH moorings. Lucky for me, the undergraduate students will be on the Jason shifts this time around! I will get to be the lead watch on these dives, and I can't wait! As we started our transit, we caught a huge pod of dolphins in our bow wake! It was awesome!
Journal Entry 6/1/2021
Jason is currently on its second dive of the day to find the PEACH moorings. Our first was successful! In fact, the supposed location of the first mooring was so precise that Jason found it within 30 minutes of reaching the bottom!
The second dive of the night, however, has not been as streamline. Once we reached the next site to be searched, there was a slight miscalculation for deployment. The pilots severely misjudged the intensity of the Gulf Stream and drifted 6 km away from the target location while descending! This left them with 2 options: drag Jason all the way back or retrieve Jason and try to deploy again in the right spot. Due some problems with the winch that accompanies Jason, they decided to drag Jason along so as to not induce more wear and tear on the winch.
Unfortunately, this was a very long and tedious task. Jason can only go about 0.5 kt or else the cables which connect it to the ship will be strained. This meant travelling approximately 6000 m at a speed of about 1 km/hr. The undergrads served as watchers on 4 hr rotations for the entirety of the dive, but I decided to stay in the van for almost all of it. Nothing exciting was happening in transit back to the target location- just lots of blue water. I got to serve my shift as the watch leader from 8 pm to 12 am which gave me the opportunity to meet the pilot on shift who happened to be the overall manager of Jason! I got to hear about how he got involved with the ROV team, his time spent working with the first iteration of Jason, and how he was involved with the design and implementation of the newest iteration of Jason.
More exciting than that was the amount of say I had in what was going on! To my surprise, most of the Jason crew has degrees in mechanical engineering as opposed to anything related to oceanography. Because of that (and being at the mercy of the Gulf Stream) the team actually consulted me for a lot of their decision making! I was ecstatic to actually be involved in the process. I also got a lot of questions regarding currents and storms around north America from the crew- I just can't describe how awesome it feels to be answering the questions of professionals in the field!
By the end of my shift, we still had not made it back to our destination. They should make it there in the late hours of the night and will begin searching for the mooring . If they don't find it, I'll have another shift in the morning at 8 am.
Journal Entry 6/2/2021
We made it to my shift for the Jason watch this morning. That comes with good and bad news: I get to participate a bit more in the Jason dive, but it means the mooring has yet to be found. Other than a few scraps of fishing line, we didn't find a thing on the bottom.
The whole situation is rather curious- not only was the mooring lost, but the steel frame which cradles it was nowhere to be found either. The most interesting thing about it to me is the fact that we might not understand the Gulf Stream to the extent we thought- we were unable to predict where it would carry the mooring and frame as it drifted down during deployment. There is also the chance that it got buried, but that would mean the gulf stream extends way deeper than we thought (which we didn’t detect with Jason while on the bottom). Who's to say what happened to it, but it definitely is nowhere near where it "should" be.
We spent the rest of the day catching up on the sorting of samples from Chincoteague. I fell back into my position of measuring mussels and whatnot. Thankfully, we finished everything so we get to sleep in tomorrow until Sentry dives and brings us more samples from Blake Ridge!
During our down time, we started working on our first cruise tradition: the decorating of cups! Everyone drew on Styrofoam cups with sharpies of every color and placed them in a meshed bag. The next time Jason dives, it will take the cups with it which will compress to a fraction of their original size! It's just a fun little souvenir for the scientists aboard. I have zero artistic ability but still made a cup of my own. The cup features a little ocean scenery with "OOMG" inscribed, a mini Gulf Stream sketch, and my attempt at NCSU's block 'S'. Can't wait to see how they turn out!
Journal Entry 6/3/2021
We've made it to Blake Ridge and started with a Sentry deployment around 10am. Since we have nothing to do until Sentry comes up tonight, I figured I'd take the opportunity to explain the general idea of what we do at each site.
There are a couple of goals for the overall study as well as some people working on various grad school projects. At each site, 3 main things happen: a Sentry dive, a Jason dive, and a CTD cast (in no particular order). Because of the SyPRID sampler on board, Sentry isn't able to carry any of its other cool equipment, so when Sentry dives, it just paddles around the seep site and slowly collects larvae so we can determine what species are hanging out there.
The Jason dives are a lot more involved since the vehicle has the capability. Once it reaches the bottom and finds the seep site (recall that Sentry is a pre-programmed, automated vehicle while Jason is remotely operated), Jason starts doing whatever the scientist in charge at the time says. This involves finding the materials left from the last dive: larval traps, tilt meters, sipuncollectors (worm traps), etc. In addition, Jason also collects many, many mussels with its arms and any tools it brings along.
If there is time, we may do a second Sentry dive. This time, however, it is launched away from the seep site. While I haven't gotten direct clarification as to why, I assume it is to see if any larvae have drifted down-current from the seep site.
Finally, we usually end with a CTD over the site. The CTD is mainly used to collect water samples for DNA analysis (a project for one of the grad students) but it also gives us great real-time data of the water column that can be used for countless other analyses. Naturally, this interests me way more than the collection of mussels and larvae- mostly because I get data that I can actually use.
After that, we move out to the next site. We always begin larvae sorting the second Sentry reaches the surface (before things have time to die), but the rest usually waits until the next day. Sentry dives are usually 8-12 hrs long so it isn't uncommon for them to come up very late in the night (hence the 8 hr shift schedules I mentioned earlier).
Well, back to sitting around and waiting.
After I wrote the above, we did get to take part in a tour of the bridge! It was really interesting to see how few controls there were for this massive ship. To my surprise, there was no steering wheel like in the movies, instead there were two throttles that controlled the thrusters- these throttles also rotated 360 degrees so they could change direction! They let us take some pictures in the captain’s chair and the chart room to finish out the tour!
Journal Entry 6/4/2021
Sentry ended up being recovered around 8 pm last night- so we had plenty of time to sort larvae and get 8 hours of sleep before breakfast today. Jason went in around 11 pm last night and was expected to come up at 11 am today… however, I woke up to a knock on my door at 9 am because Jason decided to come out early. Not a big deal, but I was stumbling around the ship having just woken up and lacked caffeine. On top of that, they determined the weather to be too intense for Sentry to dive so the CTD cast was moved up from 8 pm to about 9:30 am. I ended up missing most of that :/
But, on the bright side, we were able to begin processing Jason samples earlier than we originally planned. Since we have a 57 hour transit to the Florida Keys as soon as Sentry makes its dive and is recovered, we are all trying to finish whatever work we have ASAP so we can all just sleep for two days straight. This, of course, meant I was back on mussel duty. The dissection of the mussels is rather tedious since we have to clean all the materials we use between each and every mussel we cut open, but it still beats staring at larvae all day!
It's also a lot easier to talk about things with the other scientists when dissecting mussels. Mostly we talk about our career paths and joke about me having no idea what I'm doing since I'm the only non-biology centered person here, but it's a fun time.
Despite my lack of knowledge, I always help out with the SyPRID sorting, where I generally don't find anything. This time was different though, because I found 4 pelagosphera on my own! When I say "on my own," I mean I found things that looked weird, then called over a grad student to see if they could identify it- who told me it was nothing, then I kept staring at it and refused to believe what I heard (since it was obviously moving) so I collected it and was proven correct! Then I found 3 more! I'm less excited about the fact that I was able to identify a larvae, and more excited about the fact that I can officially say I contributed to finding larvae.
The next few days should be great. We began our 57 hour transit so we will lackadaisically finish processing our most recent samples tomorrow then sit around and do nothing until we reach the keys!
Journal Entry 6/5/2021
While underway to the Florida Keys today, we had a very lax work day. Since we have a transit of more than two days, we've been able to take our sample processing slowly. Nothing exciting or out of the ordinary from today's work aside from the fact that the mussels at Blake Ridge are Bathymodiolus heckerae- which are huge! Some of the adults are as long as my forearm! But, they smell absolutely terrible since they were pulled up from over 2000 m deep.
We finished soon after dinner then had a movies session. I don't think I've talked much about the lounge yet. It has a few chairs and couches, plus a fridge pull of assorted frozen snacks… and EVERY MOVIE YOU HAVE EVER SEEN. There is quite literally a full wall of DVDs, plus multiple terabyte hard drives full of even more movies and tv shows. We've had a couple of undergraduate movie nights since the grad students are usually kept busy until pretty late with their individual projects, but tonight we all got together and watched Mamma Mia. Oh, it was quite an experience to say the least- lots of bad singing in the at room tonight. I really do feel sorry for the sleeping crew mates!
After Mamma Mia, we watched Knives Out and Blade Runner 2049. Tomorrow, I'll work on a few coding exercises while watching even more movies!
Journal Entry 6/6/2021
Today we finally got cell phone service! As we passed by Miami, we got to not only see land for the first time since we departed Woods Hole, but we got cell service too. I got to make a couple phone calls and forward a couple pictures along to some family and friends, so that was a nice break during this 57 hour transit. From what I have been told, once we pick up Dr. Young in the Florida Keys, we will be running a tight schedule for the remaining 2 weeks since there will be very little time between sites. So, we are spending it wisely if you ask me… it is another movie day!
While I did get some coding done, we took the day to make more cups for Jason and watch movies. We watch Pirates of the Caribbean 1 and 2, My Neighbor Totoro, and Army of the Dead with ample naps in-between. Really has been a chill day.
We are expected to reach the Keys tomorrow before lunch, where we will make a Sentry dive. So tomorrow should be pretty relaxed as well.
Journal Entry 06/07/2021
We arrived at the Florida Keys site today around 11:30am and were immediately met with weather conditions too poor for Sentry to be deployed. After waiting for a few hours, we decided to take advantage of the small plankton net we brought aboard. We had it deployed to 200 m and drug it along with the ship to sample the larvae in the current.
While we didn't pull much volume up, it is a very dense sample full of all sorts of larvae. Even I have found quite a few different types! While I'm not really able to determine what exactly I'm looking at, I am getting pretty good at noticing things that don't belong.
Being this dense of a sample, it is taking a very long time to sort through it all- we are currently in hour 5 and I think we are maybe half way through. But, since we didn't deploy Sentry, we won't have to stay up too late and we won't have a dive until after we pick up Craig Young tomorrow- so one last long break before we dash through the Gulf!
Journal Entry 06/08/2021
We have officially made it half way! Today we stopped in the Florida Keys, about a kilometer or so off-shore, to pick up Dr. Craig Young. Despite the somewhat large swell, they decided to take one of the rescue boats to shore to pick up Craig and all his gear- they were soaking wet when they came back and not happy!
After he spent some hours getting caught up on our organization so far, Craig called a science meeting (only the second one we've had since we came aboard) to discuss improvements that could be made. Fortunately, we all thought everything was being ran so perfectly that no one suggested any changes! Craig seemed to be very pleased thus far.
Later in the evening, after a beautiful sunset, Craig asked if he and I could go over the data we've collected thus far from the tilt meters and CTD casts. Again, I was faced with explaining what I thought I had very little knowledge about. Thankfully, NCSU's MEAS department had prepared me way more than I ever realized- Craig was very satisfied with my plots and explanations. We talked about the mechanisms which could have led to recruitment at the sites we've visited despite the current direction not agreeing. We also discussed the various profile data from the CTD and where we would expect to have found the most larvae.
We are now in transit to the Florida Escarpment (19 hrs). We should arrive around 7:30 am, deploy Sentry at 8:30, recover Sentry at 11 pm, then it's back to sorting larvae!
Journal Entry 06/09/2021
Exciting stuff today! We reached the Florida Escarpment around 7:30 this morning and deployed Sentry soon after. The real news, however, is the graduation! Two of the science party on board (Dexter and Casey) missed their graduation ceremonies for their undergraduate degrees so we decided to have one of our own for them. While in a cap and gown, both people walked across the deck and then met their respective professors (Craig Young and Shawn Arellano). Following a short speech from their professor, they were given their degree by none other than Jason himself! I was able to take videos of both, but they are both too long to include here- so here's some pictures instead.
The rest of the day was pretty average. Sentry was recovered around 8 pm and I helped collect the SyPRID samples. Then we sorted the samples for about 2 hours before Jason was supposed to deploy. A somewhat expected delay occurred with Jason- the current was too strong to deploy here and it would have caused them to drift quite a ways away from the target site. So we went into transit to travel up the 3 kt current so when we deployed, we would land on top of the site. Worked great!
Now we are carrying on as usual with sample collection and equipment recovery. Tomorrow, when Jason is recovered in the afternoon, we will get right back to sorting and processing samples.
Journal Entry 06/10/2021
As predicted, we've digressed to our regular working hours. We finished sorting SyPRID samples after an hour or so of Sentry surfacing- the really deep samples have very few larvae in them and we crank through them very quickly. So today was another day of sitting around and waiting until Jason was recovered.
I did get to catch a few glimpses of the dive. Interestingly enough, just like off the coast of Charleston, there is a huge wall along the Florida Escarpment. I have yet to ask but since I know deep sea vents occur at subduction zones, I'd say this wall was just where the oceanic crust is forced under the continental crust. However, it seems weird that that would occur in the Gulf… I probably won't ask.
Jason came up around 4pm and we all made a mad dash to collect the samples. I discovered a new fear while doing so: deep sea worms. I powered though the first gallon sample of tubeworms; picking up their tubes, flipping them over, having all their blood dripping onto my arm, then moving them to a different bucket…. Yeah, I'm not ashamed to say I made the chief scientist do the second box. Well, she offered because she could tell I was dying on the inside (after making fun of me). Thanks, Shawn.
Nevertheless, the worms were retrieved along with the mussels, sipuncollector, tiltmeter, and larval traps. We also collected a fair amount of clams this time around. Fun fact: they bleed too. After bringing everything inside and cleaning off, I went and plotted the tiltmeter data. Every site so far has shown bottom current speeds of almost 10x the average speed for the month of June. I believe this may be due to inadequate sampling rates from their prior deployment.
I still showed the data to Craig because the orientation of the current should still be correct. While speed does matter to us, the biologists are more concerned with the direction of the current since that can help them confirm hypotheses regarding recruitment from other sites.
The rest of the day was spent sorting bioboxes from Jason, which are so dense that it takes hours to go through a single one with five people (there are 18 this time). Looks like it will be a long night!
Journal Entry 06/11/2021
We didn't get through the boxes from Jason last night, so the majority of the science team spent their day sorting. I discussed the tiltmeter concerns with Dr. He and he really cleared the air. Thankfully, the average velocities we've been given were created with a very coarse resolution model- which means our data may be perfectly fine! Once I broke the good news to Craig, we sat and discussed possible methods larvae could use to travel between sites. While we didn't come to a conclusion per se, we determined a likely method would include larvae moving through the Gulf Stream then getting caught in meandering eddies, after which they settle to the bottom.
I then spent the rest of the day dissecting mussels with a couple of the graduate students. Gruesome, but better than staring in microscopes! To my knowledge, nothing profound was discovered today. We did decide to change our course a bit today. There is a storm in the SW gulf that probably won't develop into anything major, but could turn up some winds that would be too strong to deploy in later in the week (when we had planned to be in the area). Instead, we are going to the "last" 3 sites now then circling back to Mississippi Canyon so we can beat the storm. No complaints from the science party because that means we get an extra day to work on samples from Florida Escarpment.
22 more hours of transit to Green Canyon!
Journal Entry 06/12/2021
We arrived at Green Canyon early this afternoon and immediately began a Jason dive. For the last few sites, we are going to be doing 2 Jason dives since there is equipment on the bottom that needs to come up, be cleaned, and be redeployed. While the sampling dive was starting, I went back to measuring hundreds of mussels all day. This time around, we reached over 450 mussels of various sizes. Thankfully, Green Canyon has zero mussels so no dissecting or measuring! In fact, the only samples we are collecting are of tube worms- the recovery for which I will be sure to be asleep during.
The processing of the rest of the dive samples from Florida Escarpment ate up most of everyone else's day as well. It was very slow and everyone seems to be dragging along slowly- it's been days since we did any real work for an extended period of time so everyone lost their tolerance for the workload.
As soon as Jason comes up, Sentry will go down and not be recovered until late in the morning. Then, Jason will go back down to handle the equipment exchanges. Should be an easy day, relatively speaking. Sounds like it might be our last one of the cruise!
Journal Entry 06/13/2021
We've made it to the last week of the cruise! While I'm not sick of being at sea, I do want to get back to my own bed!
Jason came up last night and was processed. Since there were no mussels, all we had to do was find homes for tube worms and sieve through some sediment. Afterwards, Sentry was sent down and we just organized and consolidated everything. We are running quite low on boxes and bins for all the samples we're finding! Since you need very specific materials for deep sea research (such as a ship, submersible vehicles, and whatnot), Craig likes to keep every specimen we find in case a colleague begins research on a species we happened to find.
Sentry was recovered earlier this morning and we sorted SyPRID samples and scattered around trying to prep Jason for its equipment dive. Writing these journal entries a day behind is getting kind of difficult since days on-site all seem to be the exact same! Nevertheless, I'm pretty sure we sorted SyPRID, waited for Jason to deploy our equipment, moved to our next location of Brine Pool, and prepared equipment for the Jason dive on Brine Pool while Sentry began its first sampling dive.
I hear interesting things about Brine Pool, but I won't describe it until I see it for myself (well, through Jason's eyes).
Journal Entry 06/14/2021
As I woke up for my Midnight - 8am shift, things seemed to be quite hectic. While I was asleep, Jason was recovered but very few hands were around to help out. This wasn’t a problem, but it was a first for us as far as I'm aware. Good thing we've already been at it for 3 weeks! After we preformed the macro-sorting (sorting all the larger organisms), we started our micro-sorting. Micro-sorting with Jason samples from the slurp vacuum (literally an underwater vacuum) is tedious because of all the sediment you have to push around. We got about half done before I had to head back to bed; running low on sleep.
When I woke up, Sentry was recovered and we sorted SyPRID samples. Afterwards, we casted another CTD on Brine Pool. Brine Pool is a rather interesting site. While it is far from our deepest site (about 650 m), there are salt deposits that create a tennis-court size area of extremely dense, salty water. So salty, in fact, that nothing can live there! Mussels grow absolutely everywhere they can otherwise so it looks like there is just a dark blue lake missing from the middle of the mussel bed! We had hoped to land the CTD right on top of it- off the bottom, but close enough to see a huge spike in salinity. Unfortunately, we missed it 🙁
Since we already had a Jason dive for samples, the most recent was a dive for equipment replacement. Sentry is performing a second sampling dive while we get to work on the mussels from the last dive. We are working with a different species of mussel at this site so we had a few extra steps with processing them. The biggest difference is we had to count hatched and unhatched egg casings attached to the mussel shells. One of the grad students on the cruise is investigating the snail which lays these.
We got about half-way through dissecting the mussels before Sentry was recovered and we got some more SyPRID samples. Before I went to bed, we transited to our last site in the area, Bush Hill, and launched Jason. He'll come up in the morning (thankfully without more mussels this time), Sentry will be sent down and recovered 11 hours later, and then we will go to our very last site of the cruise, Mississippi Canyon. We are trying to beat a storm that is forming and expected to cause huge swells though. Unfortunately, the last cruise also had some bad weather around this time and they were unable to get all the samples they had hoped for so we are trying to get there as early as possible to make up for it.
Journal Entry 06/15/2021
Once everything was said and done, Craig gave everyone an interesting task: find the larvae of a worm which looks like the larvae of a sponge, which lives on a sponge that grows on tube worms. A daunting task, I know, but apparently this is a newly discovered species that has been described a couple times yet no one has been able to keep a sample of it. Therefore, we would be finding the only sample to be kept for an extended period of time. Cool stuff- except it was dealing with tube worms so I counted myself out. I'll discover something some other time. A couple were found though, all by our undergraduates (because all the graduate students were sleeping but it still counts).
The rest of the day was spent dissecting and measuring mussels while Sentry finished its last dive on this site. Currently, there is a small debate about how we will move forward. The storm in the Gulf looks like it will get quite intense for us- too strong to deploy Jason or Sentry. If everything goes right, we will head to port Thursday evening after all our dives. If not, we will cut the last Sentry dive and head back a day early. Which leads me to quite a moral conundrum: I'm ready to head home and want to get there early, but I don't want anyone to miss out on samples. That's pretty much the consensus of everyone I've talked to.
We are transiting to Mississippi Canyon and should be there around 8 am to deploy Jason.
Journal Entry 06/16/2021
So I had my flight changed to Friday afternoon and I'll make it back to Raleigh by Friday evening. Therefore, I think this will be my last journal entry of the cruise. Hopefully, if nothing else, you got a couple chuckles here and there. I'll be spending the next 36 hours finishing the processing of the most recent Jason dive and packing up the lab. Thanks for reading!