Today was very exciting, my first opportunity to be an assistant in the control room for the ROV during a dive. The control room seats four people and has standing room for a few more. Two people handle the ROV for steering, moving the robotic arm, and communicating with the bridge of the ship to change course or speed. They also coordinate with the tender of the cable tethering the depressor to the ship, to feed out or take in line. All of this is coordinated so that the ROV moves freely and smoothly along the bottom. The lead scientist for the dive wears a headset and describes the dive, noting time, depth, and other pertinent things such as animals seen and physical features of the landscape. The lead also directs where the ROV goes, and what specimens are collected. The assistant writes similar notes about the dive and about any samples taken for study later when the ROV surfaces.
Today’s dive was in the middle of the canyon and started out at the base of the north slope at a depth of 810 meters, around 9:30am. The other two previous dives started out with a mud/sand/silt bottom, but eventually came upon some hard substrate where corals were found. However, today for nearly 500 meters of vertical landscape there was a fairly barren plain, reminding me alternately of a desert or the moon. For long periods there was little but brown mud with an occasional depression, and then a red crab, Chacean quinquedens. This was repeated often enough that a line from a poem by T. S. Eliot, “I should have been a pair of ragged claws, Scuttling across the floors of silent seas” (1) began to have a personal meaning for me.
For five hours this continued, punctuated by the appearance of the nearly as common witch flounder, Glyptocephalus cynoglossus. Also fairly common, if you mean seen once in a while, were rattails, hake, cutthroat eel, goosefish, hermit crabs, squat lobsters, and several species of shrimp. Two species of stingrays, one unknown and the other known as the torpedo ray, Torpedo nobiliana, made the viewing more interesting. By the time I added the species up, there were at least 10 species of fish and 7 species of invertebrates, and likely many more that we could not distinguish in the video. The oddest thing was a salp, a planktonic tunicate that looks like beads on a gelatinous string. So although the going seemed slow, there was plenty of diversity. And data is data: now we know that particular slope is a bunch of sediment. That is until the next turbidite strikes.
As my luck would have it, as soon as I was relieved, a field of pink anemones appeared on the monitors. Until the next time, at least I know that…
We have lingered in the chambers of the sea
By sea-girls wreathed with seaweed red and brown
Till human voices wake us, and we drown. (1)
(1) The Love-Song of J. Alfred Prufrock, by T.S. Eliot