How did I spend my last two weeks of classes this semester? In the Gulf of Mexico. Abducted by pirates.
jk. This was the closest I came to seeing pirates.
Not sure why, but this boat with some fishermen sailed right next to the ship and didn’t say anything, then sailed away.
Anyway, I was replacing someone from the USGS, who had to attend a different cruise last minute. I worked with Jennie, a researcher from the USGS, processing sediment cores for macrofauna and meiofauna analyses (basically, we were collecting mud to look for microscopic animal composition).
We left out of Gulfport, MS…
The first day, I explored the ship.
The dining area
We were pretty close to oil rigs.
While the ship sailed to our first dive location, we spent learning about safety and doing fire drills. We also had a science meeting to discuss what was going to take place during the upcoming dives.
That’s a picture of one of the captains in a safety suit. Looks pretty sweet.
The main purposes – from my simple-minded understanding – of each dive was too: image corals, collect sediment core samples, and collect samples of coral.
What I mean by “dive” refers to the dive of ROVs (remotely operated vehicles), deploying to depths of up to 1800m (they can go much deeper than needed for this cruise). ROVs can be used to collect samples, take pictures, and film the deep sea, while it is operated on the surface by pilots and directed by scientists.
On the E/V Nautilus, two ROVs are deployed at the same time each dive.
Hercules’s job was to traverse the seafloor, collect samples, and take images of coral with the “beast” cam. aka Hercules did all of the flashy stuff.
Argus’s job was to absorb the wave action of the water column and hover above Hercules with a camera so the pilots could better visualize how to move Herc – (Hercules is called “Herc” for short). Below is a view of Herc from Argus during a dive.
The names “Argus” and “Hercules” were taken from mythology. In Greek mythology, Argus is a 100-eyed giant, protector of heifer-nymph lo – which sort of relates to how Argus kind of protects Herc. Hercules was named from the Greek hero Heracles, who had ten labors to carry out – similar to how Herc performs the tasks of the dive.
Here’s what Herc looked like as it surfaced at night. Some scientists joked it looked like aliens emerging.
Anyway, the majority of people’s schedules on the ship revolved around their watch time. I don’t mean the time on their watch. I mean the time that they take part in monitoring the ROV dives. Being on watch means sitting in the control van and recording observations, taking images, controlling the cameras, navigating, or piloting the ROVs, depending on your role. Below is an image of what being on watch looked like for this cruise.
Watch schedules were four hour shifts twice a day. My watch shifts were 4am-8am and 4P-8P. The other ones were 12-4 and 8-12.
You only had to be on watch when the ROVs were in the water. Thankfully, I only had to wake up once for the 4am-8am watch. However, one time I woke up for my shift at 4am, but the ROVs were surfacing earlier than expected. They were pretty much on deck by the time I woke up so right away Jenny and I started processing samples.
Processing sediment samples typically went like this:
Step 1. direct pilot in taking push cores at end of dive, which looked like this
Step 2. retrieve push cores from Herc
Step 4 push core visual profile. Jenny would use a tape measure and describe the different layers of sediment in the core, as I recorded her observations on a sheet. I’d also take a picture of the core.
Step 5: remove top water, place core on “push-pop,” and begin slicing the different sections. This was the most time consuming part of the process.
I’m holding up the sediment core while Jenny uses a fence and slicer (idk what it’s actually called) to collect sediment in three different fractions: 0-2, 2-5, and 5-10cm. After each slicing, the sediment is stored in Nalgene bottles.
Every little speck of mud could contain hundreds of meiofauna so cleaning off the sediment between each slice took a while. In the picture above, I was looking at my glove to make sure I didn’t have any sediment on my fingers.
In the picture above, the “slicer” is in my left hand.
Step 6: sediment chemistry. Only one of the five cores was used for this. Another collaborator of the cruise wanted a sample from the top five cm of sediment for carbon dating. We had to section the sediment into 1cm increments for this researcher. That took forever. Sediment chem also involved measuring the sediment’s salinity at each layer (0-2cm, 2-5, 5-10) and the overall redox value of the core.
Measuring salinity was my favorite part of the process. You would take a blob of mud and put it in a syringe and squeeze the mud through filter paper so that only the water would leak through onto the refractometer. Sometimes the mud was so thick I didn’t think any water was in it, but there always was. I loved seeing the clear water come out of a thick clay.
Anyway, when all the macrofauna processing was done for four of the cores, and sediment chem done for the one, I would was the cores to prep for the next dive, while Jenny topped the nalgene bottles of sediment off with formalin, then seawater. We then would invert the bottles over and over to make sure the formalin penetrated the sample. Finally, we would tape up and parafilm the caps so nothing would leak out and put them away in an action packer – an exciting term for a storage tub.
At one point in the cruise, we pretty much had to switch to doing sediment chem for 6 push cores – which took so so so long. Usually, not every core made it to the top successfully so it wasn’t that long every time.
We played music a lot and talked and time went really fast!
Coral Imaging: Most of the coral imaged on this cruise had been imaged in previous years. The purpose of taking photos is to track damage and recovery of coral impacted by the oil spill. Damage was looked at by comparing photos of the coral from each year to the next. This meant that the pictures must be taken in the same location and angle as the previous pictures.
You might wonder, how the heck do coral eat in the deep? Marine snow. Fluffy snowflakes, each unique, float down from ski mountains…jk. Marine snow – the specks of white organic material that floats from the surface to the deep. This organic material can be bits of fish flesh or balls of phytoplankton which stick together as they sink.
This is also a picture of a typical coral found in the deep, hugged by several brittle stars.
The pictures of the coral were taken with a “beast cam” – really really really high quality camera – that’s screen was visualized on the surface. For the first week or so, my laptop was the only computer which allowed the camera program to run.
Above is Fanny taking pictures of the coral with Dr. Fisher.
Above is Sam focusing the camera onto the coral with a multi-focus grid.
The coral images are looked at for progression or retreat of hydroids over the years.
Coral Sample Collection: Sam and Carlos’s work involved collecting coral samples for various analyses back on land so their time was spent preserving the coral samples. Here’s some pictures of their work.
Overall, the weather on the cruise was pretty pleasant. We had one rainy day, which many of us spent watching Life Aquatic.
There were some critter visitors on the surface: sharks, dolphins, birds.
People would throw meat into the sea and the sharks would come flocking.
For the last dinner, there was a big bbq celebration.
And it ended with a beautiful sunset.
All the sunsets and sunrises were beautiful. My photostream was 90% sunsets and sunrises by the end of the trip.
The only thing more beautiful than the sunsets was the blueness of the water. I never saw water so blue.
This picture doesn’t even do it justice.