What happens to styrofoam, paper, and plastic when it’s dropped to the ocean floor?

Yesterday afternoon we dropped the mesh bags with experiments from Ms. Steinman’s Ocean Engineering class. The experimental material contained Styrofoam cups, paper cups, 2-liter plastic soda bottles with paper inside, and two Pelican brand, water-tight containers. Both mesh bags were attached to the CTD (see previous post) and went down to 1,383 meters!  Yes, meters, not feet. It took a full hour to drop the CTD and return it to the surface. I’ll try to embed a video here to show the return of the CTD to the vessel. The results are interesting, but I’ll wait to report on that until the Ocean Engineering students can see and interpret the evidence. I will include a photo of the cups and, if wifi is good, I’ll include a short video of the CTD coming up to the ship.


Cups attached to the CTD with my hand for scale.

Martha, the teacher from Bandon High School, calculated that at a depth of 1,383 meters, the pressure is 1,400 decibars, which converts 138.2 atmospheres and 2,031.589 PSI (pounds per square inch). Just for comparison, we live at sea level which has an atmospheric pressure of 1.0.  Wow! And how cool that scientists really use dimensional analysis, like Martha did. OK, so here’s a picture of the cups after they came up – unfortunately I didn’t stick my hand in the picture, so it might be hard to see the difference.


After being submerged to 1,383 m the styrofoam cups are much smaller, but the paper cups are not.

Above is a short video of the CTD being raised to the boat. The poles extending out to clip ropes on are being managed by two of the high school students. The white blobs at the top of the CTD are the paper and styrofoam cups.

Also this afternoon I saw three life species of birds – this means I saw them for the first time in my life. Birders often keep life lists; I’m too lazy to do this, but I do get pretty excited when I see a new species. The first is the Black-footed albatross – I’ve seen about 20 of them, total. While waiting for the CTD to come up, Jane and I birded on the fly deck and she pointed out a single Long-tailed jaeger. Finally, during my observation shift this evening we saw several Cassin’s auklet – a tiny, cute little bird that nests in burrows. This is a great adaptation, because the holes are small and it’s difficult for predators to pass through. I’m hoping to see Storm petrels tonight – Matthew told me about a recent discovery with these diminutive predators – apparently they can leave eggs on the nest for long periods of time, with little to no incubation. It’s thought that this is an evolutionary adaptation to the birds being blown out to sea (while foraging for food) during a storm. They are so small that it can take a long time to be able to get back to the nest, so the chicks don’t die, but their growth stops until a parent can get back to the nest.



9 thoughts on “What happens to styrofoam, paper, and plastic when it’s dropped to the ocean floor?

  1. it was nice to here u guys are doing the project with the cups and i really injoyed hereing about the birds i like seeing new wildlife as well i think its interesting to see the little way thay change from one another

  2. I think the experiment with the Styrofoam cups is totally cool. I wont say what happens only because I don’t want to give away any spoilers, but my teacher once wrote her whole classes names on them and the outcome was amazing! How do you like being on a boat and all? I’d love to spend the night on a boat. see how it is. Good luck with the rest of your research. Keep us updated on the things you do. They’re very interesting.

    • Katyna,
      I LOVED being on the boat. It was incredible – I slept well, worked hard, and had a great time. I want to do it again.

  3. I can’t wait to see what happened to the Styrofoam and plastic!I wonder what the objects did under so much pressure. Did all the material break under pressure? Was it able to hold? Did some of it deteriorate? I’m eager see the video and pictures, I also can’t wait to see pictures of the different species of birds. You know how it is over here, a lot and a lot of seagulls. Have fun and keep us updated!

  4. this is a good experiment! it is very interesting to see what depths and pressure can change about a styrofone cup. I remember doing this back in 7th grade and it was a super fun experience myself to be able to see what happens and more fun that i got to try it out myself 🙂

  5. The experiment with the Styrofoam cups was really interesting, because I never knew the results would come out like that. The results really shocked me when I saw them in class, I think I might try this experiment later on.

  6. This article had a lot of details and important information, it was cool to see the changes in the expeiriment and the ending results with the styraphome cups.

  7. I love water and birds so this blog caught my attention. Its amazing how something so light and air can become dense and compacted to the point where it shrinks or crushes things. I looked up the bird species you mentioned and the Cassin’s Auklet was my favorite. They are so cute and tiny and kind of fat too. I really love how you went into detail with everything you talked about and posted a video it really helped me picture and understand what was going on.

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