Wednesday, March 07, 2007

Aquarium Life: Cleaning the Octopus Tank

A Pacific Giant Octopus (Enteroctopus dofleini) is arguably the largest invertebrate. It is also the most intelligent and capable of solving complex puzzles, even removing a piece of fish from a jar by unscrewing the lid. During my almost two decades of volunteering at the Aquarium, I've experienced and heard many stories about these animals.

The first time I got a tour of the old Aquarium in all it's worn concrete, wet-rushing-water glory, I got to see the octopus tank. The tank was triangular shaped with concrete on two sides and the viewing window on the third. It wasn't a very large tank, but big enough for the octopus. If you wanted to see into the tank itself you had to climb onto the walkway and lean way over so you could peek inside.

"Why is there Astroturf on the sides of the tank openings?" I had asked. I thought this was for the person working in the area to hold onto.

"That's to keep the octopus from climbing out," my old friend Lloyd had told me. My friend Lloyd has passed on now, but I know he'd like that I was telling you this story. He went on to explain that the octopus would sometimes try to escape and they found the best way to keep them inside the tank is to put pieces of Astroturf or burlap around the openings. Apparently, an octopus doesn't like rough surfaces.

"But why is there Astroturf on the pipes over the tank?" I had asked. The ceiling of the old Aquarium was a twisted maze of pipes, some labeled "hot fresh" some labeled "salt," many with no labels at all.

"An octopus can swing it's legs high enough to grab the pipe and pull itself out of the tank," he explained. Then without further comment we moved on to the tropical section of the Aquarium.

I couldn't really pay attention to what Lloyd was telling me after that. I would have to learn about the tropical saltwater fish later on because I was too busy being stunned by visions of a giant octopus grabbing the pipe with one of its arms and swinging itself out of the tank, much like I used to swing on the monkey bars when I was in grade school.

A few years later Curator Biologist convinced me to take on the task of cleaning the octopus tank. I'm sorry I only did this task for a short period of time because it was such a blast.

The procedure was I had to drain the water out of the tank to about knee level, climb inside in my hip waders, carefully pick up Dungeness crab shell pieces while not startling the octopus, climb back out and refill the tank. I forget how many gallons the tank was, something like 400-500 gallons comes to mind, but the tank was deep enough for me to swim in.

While the tank was being drained, the octopus would move to the lower left corner where the viewing glass was and huddle there. It's arms would be constantly moving along the surface of the water, checking for when the water level would start to rise again. Once the water was shallow enough for me to stand in, I would pull myself over the top of the tank. The walls of the tank were thick enough for me to sit on. Then I would carefully drop into the tank, making sure I kept an eye on where the octopus was at all times.

The first time I did this, I was surprised at how cold the water was. The average air temperature in Battery A where the octopus tank was located was probably somewhere in the middle 60s. The temperature of the water in the octopus tank was in the lower to mid-40s. I would stand there with my plastic bucket picking up large crab pieces and start shivering from the cold.

I would move slowly and carefully. Although the octopus never moved far from that lower corner, I was still intimidated by its arms moving around constantly. Since I was visible to the visitors they were always rapping on the glass. I would turn, smile and wave. Sometimes they would take my picture although I'm sure the picture never came out well since the tank glass was always foggy.

A dilemma came when I was finished picking up all the crab shell pieces, but the octopus by now would feel a little bolder and start to move slowly along the viewing window glass. This meant that the octopus was sitting on some pieces of crab shell I needed to pick up. What to do? The first couple of times, I left it alone. I mentioned this dilemma to another volunteer and she said you can sort of shoo the octopus back into its corner by nudging it gently.

I was very skeptical about this idea, but after the third or fourth time I tried it. I moved until I was standing next to the octopus and then gave it a gentle nudge so it would get out of the way. This was the first time I had ever touched one and it was amazing. If you look at an octopus you might conclude that they are slimy to the touch. Instead, they are very soft and smooth, almost silky. If you were to pick one up, it would sort of ooze between your fingers and hands.

I never tried picking one up, but people who have had the pleasure of doing so assure me this is true.

When I was done, I would climb out, turn the water back on and perch myself on the end of the tank while the water refilled. This was to make sure the tank did not overflow and to make sure the octopus was all right.

I sure did love that little task, but it's not likely there will be another opportunity to do something like that in the new Aquarium. If there is an octopus, it will likely be put into a very large tank that people would have to dive into in order to do maintenance and I'm not a diver.

1 comment:

spmackin said...


A shred of grey and bit of carapace
rain from a couch hid in a thin crevasse,
a sign of nature's mute mouthed avarice,
debris to feed the tall and coiling grass.
An octopus uncoiled assumes an ooze,
a sentient goo across aquarium glass
on cups beneath a crinkley crimson mass
to see by tendril touchy sly embrace.
As shadows on the broken water trace
it vomits darkness to impede a chase
then like molasses seeps into its place.
I find molasses to be an excess,
it is effrontery to time and space.
What's as preposterous as an octopus?