March 13, 2003: Leg 3, Day #2
Today's dive took us more than 3,100 meters
down into the deepest part of the Gulf of California. We saw some
wonderful animals and made some important collections. Tonight we will
head northward to the next basin in the chain of deeps that form the floor
of the Gulf.
This morning we launched again into calm seas and nearly ideal surface conditions. We quickly entered a layer of flashing blue lights that surprised us with their intensity and abundance. The source could not be bioluminescence because we were still near the surface, and the water was well illuminated by the sun and by ROV Tiburon's lights. Instead it was the iridescent bodies of tiny copepods, aptly named Sapphirina. Under a microscope the bodies of the males do indeed resemble sapphires, and the shining colors they reflect rival the plumage of the brightest tropical birds. Bill Hamner explained to us that groups of male Sapphirina arrange themselves into specific spatial patterns and use their bright reflections to signal females.
When we entered the oxygen minimum layer today, we found many more fishes than we saw yesterday. Their numbers grew with increasing depth until we were between 400 and 500 meters, where their abundance was the greatest. Here we saw myctophid lanternfishes Triphoturus mexicanus and Diogenichthys laternatus and the bristlemouth Vinceguerria lucetia.
And speaking of nets, ours is still lost,
somewhere between Guadalajara and La Paz. This means that we have to
change the entire cruise plan and a couple of the projects, but then
little challenges like this are what make expeditionary science so much
Osborn looks pretty happy tonight. Today we observed and collected
five different kinds of munnopsid isopods, or "spiders" as we
call them. Karen studies these deep-sea spiders using classical
morphology-based systematics, woven together with state-of-the-art genetic
techniques, to establish the relatedness of the different munnopsid types.
She is using this as an organizational background for studies of their
biology, ecology, and biomechanics.
Another endearing aspect of expeditionary
science is that glitch gremlin I referred to a couple of days ago. Today
we had to dive without the system that links all of our data together so
that it makes a coherent database. The system also affects our ability to
annotate our videotapes, make video frame grabs, log data, know where we
are... little things like that. Throughout the day, the ROV
team, and in particular Dave
French, worked hard to repair and reconfigure the system.
Finally, after many hours of effort, including phone calls back home to Doug
Au, Dave fired it up, and we are back in business.
The Tiburon is back at the surface
15 hours after we launched her this morning. But the day is far from over
because our animals have just arrived, and many of us will be up the rest
of the night working with them. They are the rarest of commodities, living
deep-sea critters. While we work, the R/V
Western Flyer will be carrying us to the Farallon Basin. More