Scavengers: part 2

The camera system

While we're waiting for the wind to calm down, my team turned into scavengers ourselves! We decided to collect any samples we could from the harbor. With Erlend's help, we were able to use the Polarsirkel boat do deploy the plankton net in the harbor and to conduct the first field test of a camera system I've been working on.

Cameras are powerful tools for seafloor research. Sometimes just seeing what's there tells you a lot. Most underwater cameras are expensive and heavy and difficult to transport internationally (because you have to fiddle with insurance and customs and blah blah blah). Because most of my research takes place in remote environments, I wanted to develop a cheap, simple, lightweight camera system that I could take with me anywhere.

I bought a small, simple camera and found an underwater housing for it that could withstand high pressures, up to 20 atmospheres. That means I could theoretically deploy the camera up to 200 m depth. Then I bought four underwater lights - the brightest, sturdiest, cheapest ones I could find - that were also certified for use in up to 200 m of water.

One of the best photos from the camera test.

To hold the camera and the lights together, I'm using a frame made of PVC. Usually, PVC pipe is used for plumbing, but it's also a standard tool in marine biology - you can build a lot of things out of it! The biggest advantage is that I can take the frame apart for transportation and then re-assemble it when I arrive in the field. I drilled holes in the PVC so the pipes would fill with water (instead of being filled with air and floating on the surface), and I put some steel rods inside the pipes to make the camera sink. I also ran a thin polyester rope through the entire thing to add more tension and make sure I didn't lose the camera or the lights if the PVC came apart underwater. For the last step, I hung a small piece of pipe below the camera. Ideally, this pipe will rest on the seafloor and serve as a color and size scale for my images. I'll be able to measure things because I know how much space is between the different pieces of tape.

We tried the camera system for the first time on the Polarsirkel boat yesterday, and it seemed to work ok. The images are not amazing, but I'm at least able to tell what is on the seafloor. In the harbor, it appears to be mostly small rocks and kelp. I figured out I need to add more weight so the camera sinks faster and doesn't get swept away by the current. I should also try covering the lights with something translucent to diffuse their beams and brighten more surface area of the seafloor.

Overall, not half bad for a homemade sampler!