20
March 1999
Kaikoura, New Zealand
What
an incredible day we've had! It started very early again, at 0500, as we had
the third of our scheduled video conferences with a school group. We connected
with the John C. Stennis Space Center in Mississippi, where nearly 300 students
from southern Mississippi and Louisiana had gathered to learn about the progress
of the expedition and to ask questions that their studies about the giant squid
and the expedition had prompted. Bernard Brennan, our bioacoustics expert, joined
me in the presentation and Q & A.
Then we raced out to the KAHAROA at 0720 on the tender, RUKAWAI, for an early start on the dive of the day. Unfortunately, both the ship and the sub had technical problems that had to be solved before we could head out to conduct a detailed depth-sounder survey of the bottom where we wanted to dive. We found good divable bottom and completed our dive plan. Just then we looked out the windows on the bridge of KAHAROA and saw a big sperm whale on the surface less than 1/2 a kilometer away! That squid-eating whale was all the confirmation we needed to convince us that we had selected the right spot for today's dive!
Because
we have had trouble on former dives getting the sub into the deepest spots we
need to go, we devised a new "plan of attack". Scott, the very experienced
sub pilot, flooded the ballast tanks completely, adding all that heavy water
to the ballast, then pushed the down-thrusters
to full speed ahead. He was on the bottom at 2135 feet (ca 680 meters) in less
than 30 minutes. And what a bottom it was! First, this represented a new deep
diving record for New Zealand waters, breaking the old record we set last week
of 1776 feet (ca 550 meters). We left our mark by setting the sub onto the soft,
muddy bottom, where the impression of the heavy battery pods will remain visible
for many years.
Second,
the near-bottom waters and the bottom were teaming with life. As we had come
down through the water column, we went through the deep scattering layer and
saw thousands of small fishes, mostly lantern fishes and pearlsides, plenty
of midwater shrimps, as well as many different kinds of jelly-like animals:
medusae, salps, siphonophores, arrow worms. As we approached the bottom, we
were greeted by several of the silvery-sided
hoki, fish which gracefully swam around our camera, clearly attracted by
the lights. Once we reached the bottom, the hoki were joined by many other kinds
of deep sea fishes. During the course of the 3-hour dive several species of
grenadiers, often called rattails,
slithered and danced by our cameras. One species, of which we saw at least 10
specimens, was a beautiful fish with a series of black bands along its body,
sharply in contrast to the interspersed silver bands; the long dorsal fin was
tinted with a brilliant white tip. This certainly was a good demonstration that
not ALL colorful fishes live in the shallow seas and coral reefs!
Other
fishes, too, kept us excited as we sat glued to the monitors in the research
lab, eager to learn whatever secrets awaited us in this deep sea ecosystem.
A round, shiny black, big-eyed, spikey oreo
fish put on a show as it lazily swam along ahead of the sub. It clearly was
not disturbed by the presence of the sub nor by the bright lights, as it sculled
with gentle undulations of its dorsal and ventral fins, not bothering to use
its caudal (tail) fin at all. I suspect that that is used only when the oreo
needs to put on a burst of speed to capture its prey or escape an enemy. Could
that include the elusive giant squid? Possibly so... . I think the reason I
was so excited about this productive dive site is that the small amount of information
we do have about what Architeuthis eats, indicates that both hoki and
grenadiers are among the prey. So, if food is present, can the predator be far
behind?
As an invertebrate zoologist, I do not want to neglect the wonderful invertebrates we saw on the bottom. Among the first images to greet us as we settled on the bottom were vivid impressions of large sea stars in the soft gray sediment. Then we began to see the brilliant orange and red sea stars themselves, some of them lying flat on the bottom, and some of them with their bodies hunched up in a high dome, presumably feeding on some of the numerous, slowpoke, hapless mollusks (snails).
Another
echinoderm, like the sea stars, was the heart urchin, also very numerous in
the soft sediment. Scott made a great catch with the manipulator and brought
back to the surface a beautiful specimen of the spiney, oval
heart urchin.....not that the urchin demonstrates blazing breakaway speed,
of course! Finally, the type of bottom varied between the soft, fine sediment
with few macro-organisms to a bottom characterized by a more solid structure
with a network pattern of low ridges. The most abundant animals there are the
narrow, cylindrical tube worms that rise several centemeters above the substrate.
When we first saw this scene, we were reminded of a mowed field with only the
stubble remaining. As the sub approached each patch of these worms, little puffs
of sediment shot out of the tubes like smoke from miniature chimneys.
The wonderfully successful dive ended early in the evening. Again we had to race off the ship and back to the motel, because we had another video conference scheduled for 1900 hours (7 PM). Driving back from South Bay, I got a cell phone call from Dr.Steve O'Shea, my colleague from NIWA in Wellington. He had just gotten word that ANOTHER Architeuthis had been caught down off South Island!!! That makes SIX just this year, matching what Steve had predicted!
So,
by the time we made the video phone connection with the Rachel Carson Middle
School in Herndon , Virginia, we had lots of new and exciting information to
share with the 120 students who were spending the night at the school, having
a Science Sleepover. Bernard joined me on this presentation as well, and even
though it was 0130 in VA, the students seemed very enthusiastic and alert. And
what great, challenging questions they asked! The teacher who organized this
stimulating event was Rick Wormeli, with whom I have worked for a number of
years giving presentations and projects on marine biology and oceanography.
Perhaps Bernard and I were able to gain a few new recruits for science. After
we finished the video conference, we held an impromptu meeting to plan the dive
for tomorrow. If things go as we plan, we will have another great day!
Cheers,
Clyde