Week 8: Sedated Seals and Spreadsheets

Apr 10, 2019

I really had to think for a while for that blog title… But I’m proud of it.

On Thursday, I went in to the lab and ended up in a building called the Younger building, which is, oddly enough, not the youngest building, just named after a guy named ‘Younger’. It’s home base for all the field trips to Ano Nuevo and elsewhere, it’s next to the building with all the real labs for blood work and the like, and it’s attached to the quarantine areas for seals and the pools that are sometimes used for experiments. In other words, it’s a seal area. Around this time of year, procedures are ongoing to implant short-term trackers in seals and translocate them. The general idea is that researchers can sedate the seals at Ano Nuevo, bring them back to the lab (called the Long Marine Lab, or LML, or specifically the Costa Lab for elephant seals), re-sedate them, operate on them, put them back on a truck, drive them to Monterey (south of LML on the other side of the bay), and get them into the ocean. Then they swim right back to Ano Nuevo, where the devices implanted in them are recollected and used in their respective experiments. It’s a shorter version of the major tracking projects, where seals will travel tens of thousands of kilometers and spend months at sea in between attaching trackers and recovering them. The experiments being conducted don’t need long distances, just information about the seals.

On Thursday, the experiment was being run by a researcher who was studying thermal regulation of elephant seals in the water. It’s an interesting topic, because seals dive thousands of meters to where it’s really friggin’ cold, but somehow they’re fine. When I came into the lab, the seal was already there, in a long rectangular box. She wasn’t actually sedated, just really chill. There was a second seal that we just picked up and moved a but but she didn’t complain. It took eight people to move the one seal down a couple feet from a table, and that was with nice handles on the box. She was incredibly heavy. They’re really dense (not stupid, just heavy).

But back to the seal we worked with, we let her out outside in a small enclosed area next to the Younger building, next to the pools seals are sometimes kept in. She kinda flopped around for a while, and we sprayed a bunch of water on her with a hose, to mimic her getting out of the water. Then the researcher I was working under (not my advisor Rachel) started taking thermal images with a FLIR camera at regular intervals, and noting hot and cold spots on the animal as it dried and was re-sprayed. It was pretty cool, but I don’t really understand the meaning yet. I think that part of what they were looking for was how scars are heated, because the female we were working with was pretty scarred. After that, we sedated her (she took a really long time to go down), loaded her into her rectangular cage, put her on a trolley, and moved her inside (it took like ten people, she was even heavier). Then the real work began. There were at least six people constantly operating on her or attaching devices or giving sedatives or helping with any of those tasks. As I am inexperienced with literal surgery, I sat to the side and recorded drug dosages, which is important for two reasons: first, we need to keep a constant stream of sedatives (ketamine) and relaxants (valium) in her system to keep her immobile. We also use lidocaine for the surgery spots, to decrease pain. There was an insane amount of sedatives injected into her spinal vein while I was there, because there’s just so much mass to saturate. Second, some of the drugs we use are controlled substances, so we need to keep track of every single vial in the lab to make sure nothing goes missing.

The procedure involved implanting thermal sensors in her side, attaching those to a data recorder, attaching an ARGOS tag (similar to GPS positioning but slightly different), attaching a depth-time sensor, and taking a ton of morphometric readings (length, girth, flipper length, whisker samples, slump height (basically the height of the seal when it’s flopped on the ground, and some others). We even took a bunch of photos to create a 3D model of the seal (I don’t know how it works but it sounds complicated lol).

I didn’t get to stay for the whole procedure, but I was there while the seal was under for over two hours, and they were just making the first incisions to insert the thermal sensors (the whole sanitary and clean procedure thing is wild – keeping things sterile is a big deal).

On Friday, things were considerably less interesting. As the title may suggest, I worked with some more spreadsheets, in specific my spreadsheet and a bunch of ones containing information about the weights of weanlings. Once I had obtained the tag numbers of the babies (explained in my last blog post), I had to open up a bunch of different spreadsheets to find their weights. I’m looking at the weights of the babies at the time of weaning, right after they have stopped getting milk from their mothers, because I’m interested in how well mothers can feed their pups based on their personalities. The problem is that not all weaners (read: none) are weighed at the exact moment that they stop feeding. As they are feeding, they grow in size and weight, as they are receiving nutrients. But at the moment that they wean, they start losing mass, as they aren’t eating (remember that elephant seals don’t feed while they’re on the beach, not until they go out to sea). So there are formulas to back-calculate the weights of the weanlings at the exact time of weaning. That’s one spreadsheet, but it doesn’t have every weaner, because not all of them have been back-calculated. So I found as many as I could on that spreadsheet, because that’s the best data. Then I went to the raw data website. Funny enough, that was the one that I had just searched for tag numbers, just a slightly different search preference. So I got the rest of the data from there, and tried to make a graph of it. Honestly, not to get too hopeful, there is some sort of relationship between the mothers’ reactions and the babies’ weights. I’ll post the graph later if I can, but I’m still getting more data and more videos so it isn’t done yet.

Well this has been along post, and hopefully you’ve gotten through it all 🙂 I think it’s pretty cool.

One Reply to “Week 8: Sedated Seals and Spreadsheets”

  1. Helena Vervoort says:

    Very exciting to witness seal surgery! Thanks for sharing!

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