Kaikoura, New Zealand
Today dawned bright and warm, with almost no remnants of the southerly swells that had prevented us from launching yesterday. Everyone benefited from the downtime after the 40 knots per hour battering we took all Tuesday night and Wednesday morning.
The dive plan for today calls for the sub to go to the bottom in about 400 meters and to sit on a flat spot with the thrusters shut down and the main HMI camera lights turned off for an hour or more. We want to see if the reduced light levels will be more attractive to animals. Will we see different species? Will the familiar species behave differently? Will Architeuthis come to investigate the quiet, dimly glowing intruder into its haunts? We know that many squid are attracted to the glow produced by chemical light sticks, so Scott and I discuss placing some inside the capsule. I also attach eight other light sticks on different external parts of the sub, all in view of pilot Scott or the cameras. Because the low light level camera (SIT-Cam) located on the starboard manipulator will operate during the period of reduced light, I want to make certain that anything attracted to the light stick gets captured on the SIT's video tape.
With Mate Jo at the helm of the RUKUWAI to tend the diver, we prepared to launch in 400 m in what looks like reasonably flat bottom a few kilometers off Bushett Shoals towards the southern end of Conway Trough. The descent is characterized with an unusually thick soup of plankton, providing lunch for marauding Myctophid lantern fishes and Euphausid shrimps. Once on the bottom we know we are in good food land for giant squid, because the hoki and rattail fishes are very abundant. While Scott tries to find a good place to settle down and shut down, we see a great diversity of organisms: silvery white spineback eels, slithering off into the inky blackness, the little craters and domes produced by the silt-loving polychaete worms, hermit crabs lunging lazily through the soft mud carrying their snail shell mobile homes. We traverse fields of lovely pastel pinkish orange sea anemones, all bent over in the same direction, leaning into the slow current to gather food. The little heart urchins that were so rare during other dives are very abundant here in certain areas, where they look like extensive patches of puffball mushrooms on a cool fall morning. Neil, Di and I had a great show of biodiversity in the deep sea.
Scott finds a relatively flat place to stop for our lights-out experiment. But there is no such thing as still waters, even here in the deeps. In spite of all his good efforts, Scott is unable to "plant" the sub firmly on the bottom. But we decide to douse the lights and give it a try. The experiment has to be abandoned after a while, as the wind on the surface begins to increase steadily and, consequently, to drag the sub out of position. Oh, well, it seemed like a good idea at the time!
When I am able to tear away from the monitors, I go to the bridge to discuss the next moves with Captain Evan and sub chief Jeff. We decide that given the amount of power left in the batteries, the increasing winds, and the already successful observations, we should retrieve the sub now. I look back through the echo sounder traces to see where the sub has been working and am thrilled to see the trace of the sub as viewed by the depth sounder while the sub was descending through the water column at the beginning of the dive, a sub dive profile.
We reluctantly leave the bottom and begin the ascent that will bring the sub into the sun-drenched, sparkling waters, where the retrieval goes off without a hitch. This team is really together. I am only too aware that tomorrow will bring the last dive of the expedition. Will Architeuthis chose to reveal its cryptic haunts? Tomorrow is another day.....
Best wishes from
the seas and mountains of beautiful Kaikoura,