17 February, 2001

Back on station

One of the few things we could do when the weather was bad was take a rock dredge and drag it across the ocean floor to collect rocks. Not only rocks came aboard, but also many aquatic critters! Rob Beaman, one of our Australian scientists, collected all of the critters, even using sieves to separate out the increasingly smaller ones. It was so interesting to see the types of animals that live on the ocean floor. There were coral and bryozoa (what are bryozoa? They looks like a plant or seaweed, but are not). I was most surprised by some of the sponges we collected - they are made out of fibers that look just like fiberglass. This fiberglass substance is made out of silica (what's another mane for silica?*). In Antarctica, silica "rules" due to the lack of calcium carbonate in the water column. Sometimes there are so many sponge skeletons on the sea floor that they forms large" mats". Tubeworms were another interesting critter in the dredge. (Find the picture that looks like a root. Do you know what it is? Where might it live, and why the root-like structures around the outside?) * And just when you thought there was a place on earth without spiders, we found one: a sea spider. (Why did we use a pen in the picture?) Sea spiders are actually more closely related to crabs. They have a huge proboscis (nose) with sucking mouthparts and a tiny abdomen. They feed by inserting their proboscis into sea anemones or bryozoans, and then sucking out the fluids. Once we laid out and grouped the specimens, Rob photographed and weighed them. In the last photo, I am searching for information to describe the critters that we have collected, and writing their scientific name on the specimen bottles. Why would we want to write the scientific name as well as the common name?

*glass

* they live in the mud and need the "roots" to anchor themselves into the sediment