A coral observed by ROV Bathysaurus
Orange roughy (Hoplostethus atlanticus)
A macrourid fish
Date:11 July, 2004
Author: Michael Vecchione (NOAA, NMFS, USA), Anders Thorsen (IMR, Norway)
In many ways, today has made up for the frustrations that we encountered yesterday, although it did not start out with much promise. An early morning bottom trawl at the shallow station just to the east of the Ridge's central rift valley "hung up" (got caught on something big, like a rock outcrop) for a while as soon as the net reached the bottom. When the net was retrieved at the end of the tow, we discovered that the headrope had broken. This means that the net could not maintain its proper shape while being towed. There were a few rocks but no bottom animals in the catch, just some fishes, shrimps, and jellyfishes that live higher up in the water.
However, while all that was going on, the ROV team had finished repairs to the deep ROV, named Bathysaurus (which means "deep lizard"). Bathysaurus was immediately deployed to test it, and this test dive turned into a very successful operational dive for this station. The ROV was launched at about 0320, ship-time, and made it to the bottom a little over an hour later. We spent the next 3.5 hours remotely exploring the bottom at depths of 1030-1165 m. Bathysaurus was able to record excellent video observations of the area. Bottom living animals that we saw included deep-living corals and their relatives, long-spined sea urchins, and sponges. We also got close-up looks at many fishes and saw the microhabitats with which they were associated. These fishes included oreos (which, disappointingly, don't look much like the cookies), rattail grenadiers and hake-like fishes, orange roughy (which aren't always orange but are rough looking), and even a shark. There were very large, bright red shrimps sitting on the sediment. Much of the sediment here seemed to be fragments of dead deep-living corals that probably came down the slope from higher elevations on the ridge nearby over many, many years.
After the dive, everyone was tired but elated. However, there was little time for rest. A new trawl net had been rigged and we had returned to the deep rift valley running up the center of the ridge system. We repeated the trawl station there that had been unsuccessful yesterday. The depths within this part of the rift valley are greater than 3000 m and we have to use almost all of the wire on our winch drums to fish the net on the bottom there. The successful catch today, although not large, was extremely interesting. There were diverse and bizarre sea cucumbers and many kinds of deep-sea bottom fishes. The highlight for one of us (MV) was an unusual bigfin squid, of which (as far as I know) only one specimen has ever been collected before, in 1936. I look forward to returning to the museum to study further this and many other very unusual deep-sea cephalopods collected on this cruise.