Jasmine Heuberger-Yearian Blog Leg 4

A CTD installed on the seafloor at Axial Base. Credit: UW/NSF-OOI/WHOI; J2-1554; V23.
Sea pigs on the Axial Seamount base. Credit: UW/NSF-OOI/WHOI; J2-1554; V23.

12 September 2023

As my seasickness alleviates, I head out to the van for my first dive at the base of Axial Seamount. As Jason descends, there is an immediate change in the ecology. From 100 to 200 meters, the distinct creatures are long siphonophores, thousands of single-celled organisms working synchronously together, linking the connection between single-cell life and multicellular creatures. From 300 to 400 meters, indistinguishable green blobs appear along with distinct jellies. As the vehicle continues to descend into the bathypelagic – midnight zone – a purple dinner jelly with both upwards and lower tentacles flows by. As Jason reaches the bottom, the sediment immediately appears differently in a reddish tint. The only visible macro species are species are starfish attaching themselves to the substrate and sea pigs, scavenging the dusty sediment.

Following our shift, we hear a call of a Mola Mola sighting. Though I’ve never heard of this species, I run to the side of the ship to see the large faint white shadow deep in the waters. Minutes pass, and the creature gets closer to the surface, and it now floats above the surface with its large weight, almost basking. As I observe the massive fish, there are visible tears on the fin and marks of parasites. The sheer mass and serene slowness make me wonder what predators it faces and if it can possibly defend itself.

Mola Mola sighting. Credit: J. Yearian, University of Washington, V23.

The Chief Scientist, Katie, shares with us her Ph.D. research at Kaikoura Canyon in New Zealand. There, lies an occurrence of disturbance ecology, a highly productive benthic community that resulted from a turbidity flow.

Axial Seamount parallels being a rich occurrence for megafauna, and the importance of hydrothermal vents as a climate proxy. The Blob event of 2015 showed unusually warm surface temperatures from a satellite. Using the shallow-water profiler, the impact beneath the surface was exhibited in the top 200 meters of the water column, which dissipated following the Blob event. Small changes in climate can also risk the homogenization of such unique environments.

The 13th continues with more CTD operations and deep profiler alerts until dusk when we hear unfortunate news that the ROV Jason’s power transformer had been damaged. The ROV was quickly being fixed, but given the valuable time we have remaining, the decision was made to leave Axial Base and make the 18-hour trip back to the Oregon Offshore site.

Screen grab of the Jason monitors showing the successful deep profiler instillation on Jason Dive 1552. Credit: J. Yearian, University of Washington; V23,

11 September 2023

In the early morning, we headed straight to dive duty. This time, I was assigned to recording and capturing shots of the dive. We launched the Deep-Profiler vehicle, attaching it successfully to the ROV’s front and then proceeded to recover the old deep-profiler vehicle from off the mooring cable.

This dive presented numerous technical challenges, with complexities arising from Jason’s manipulators, ensuring a secure fit of the guide plate into the cable for stability. Unfortunately, one of the arms on the old DP broke due to the sheer weight of Jason’s manipulator arms. Nevertheless, we managed to recover it steadily.

Afterward, in the lab, Andrew shared his research on the diversity and population structure of scaleworms at Axial Seamount, specifically focusing on the polychaetae, which possess many sets of organs. Similar to bull kelp, these morphologically diverse creatures can serve as environmental indicators, playing a significant role in signaling genetic drift around Axial Sea. Andrew shared Deb Kelley’s analogy of the upper ocean crust permeability to a bag of marbles, with the pores filled with seawater and hydrothermal fluids.

Andrew giving me and Aakriti a tutorial on Niskin bottle sampling. Credit J. Yearian, University of Washington; V23.

Operations swiftly transitioned to CTD casts, where we collected water samples from the Niskin bottles. The oxygen samples were fixed and inverted to mix the chemicals. I continued to learn the process of taking samples for chlorophyll and salinity. With our rubber boots, we released the metal weights that kept the bottles close, and the remaining water samples were thrown overboard.

As we completed our sampling, we secured any loose materials and prepared for the long-awaited journey to Axial Base. We rushed up to the deck to watch the boat depart while experiencing the rise and fall of the waves. The gusts of wind and my lack of sea medication began to affect me. I hurriedly retreated to my cabin on the ship’s floor, where I stayed for the next 15 hours. On the morning of the 13th, the ship came to a stop, and my seasickness symptoms finally subsided. We had officially arrived at the base of Axial Seamount.

A view of the bridge on the R/V Thompson. Credit: J. Yearian, University of Washington; V23.

10 September 2023

Accustomed to navigating with rudders and propellers, the R/V Thompson varies from the traditional navigation system. ECDIS, the Electronic Chart Display and Information System, automates such processes.  Route monitoring, using RADAR, currently spots groupings of fishing boats about 2 miles away. The X-band radars quickly pick up immediate surroundings, while the S-bands can cut through the rain clutter.

Instead of a standard compass, affected by variation in the Earth’s magnetic field and the heavy metal on the ship, a gyrocompass is used, based on the rotation of the earth. Though these advanced instruments are used, Victor still checks the gyrocompass error using celestial navigation. 

The RADAR displays obstacles including the possibility of hitting a nearby ship, how close it will be, and at what time. AIS, the boat tracking system, picks up call signs including how fast the boat is going, and the type of activity, which can be accessed through Marine Traffic.

An inclinometer used to measure the angle of the boats tilt, useful in situation where importing cargo on to TGT, in which the amount of needed correctness can be measured. While we are “stationary”, dynamic positioning performs calculations made to balance each 360-degrees thruster within 10 meters of the fixed spot.

Other indicators include how fast were turning in each direction to alert rudder navigation. Multiple compasses, an echo sounder, and a speed log showing how fast we’re going in each direction, and the depth, to alert rudder navigation. The tour culminated with the most important piece of equipment, the coffee maker.

Blue shark on dive J2-1550. Credit: UW/NSF-OOI/WHOI; J2-1550; V23.

7-10 September 2023

In preparation for leaving port, we ran through EAP drills, tried on immersions suits,  had a briefing of the remotely operated vehicle Jason, and data logging techniques.

Last night at dusk, we left port soon to replace the Newport lights and fog with the curves of the sea.  With the RCA technician Andrew Paley, I sanitized the Isobaric Gas-Tight Hydrothermal Fluid Sampler with nitrogen, and secured equipment. As the wait continued, Katie, the chief scientist, shared her expertise in megafauna mapping along methane seeps of the RCA. Currently, we are near Primary Node PN1C of the Regional Cabled Array along the Cascade Margin at the Oregon Offshore  site recovering the Deep Profile mooring , and deploying.

As my third shift started, my first time in the Van began. The van is a highly equipped ROV monitoring site for Jason, an elevated shipping container on the ships deck. I took the task of working on the Sealog client, documenting all the movement of the ROV and its surroundings. Starting in the Epipelagic Zone hundreds of sardines appeared.  Given it being dusk and the bright lights of Jason, two Blue sharks found the perfect spot for feeding hour. 

Screenshot of Jason monitors showing a school of Sable Fish at the Oregon Offshore site . Credit: J. Yearian, University of Washington; V23

As we continued down towards the Mesopelagic zone, bright red squid, jellies, and other indistinguishable bioluminescent creatures come and go. Soon to follow, a mysterious cloud of sediment appears blocking our vision, followed by a swarm of sable fish. After much trial and error, we located the beacon.

Tonight, September 10, is my second night in the Van.  I watch them locate the Junction box, where a large red Rock fish resides.  The Navigator was introduced to K-pop, soon to be followed by array of aux requests including Taylor swift, Rainbow Kitten Surprise, and Steve lacy. After a few attempts to connect the power cable to the docking the pins were being blocked by the docking situation, causing a delay in remediation. We retrieved another beacon and the dive complete.

As the fog and mist rolls in, tonight we will transfer to the slope base. I am elated that I have not fallen sick, and hope for a smooth transfer ahead.