Tuesday, November 14, 2006

Hijinks on the High Seas, part I

I spent October on this boat, as a visiting scientist for leg 3 of this cruise. The weekly reports make pleasant reading, if you're in to that sort of thing. Progress in each of the cruise's main science pursuits (marine mammal sighting, biopsies, and photography; birding; oceanography; acoustics; dip netting and catching fish) is summarized in the reports by the scientists in charge of each task.

However, if you're interested in a less professional perspective, you can read these excerpts from the journal of a marine biologist who was till recently almost wholly ignorant of marine mammal biology.

October 9, 2006

I just saw three blue whales! They were spotted a long way off, but we chased them until they were right at our bow, and we could look down from the flying bridge at the very top of the ship and see their long, long bodies just under the surface. We could also see three scientists perched at the bow of the boat, two holding crossbows and one, a rifle.

Bizarre, yes. The weaponry is for biopsies. They shoot small darts that nick a little bit of tissue from the animal's hide. The dart doesn't get attached to the animal; it gets reeled back in to the boat, or, if the line snaps (which seems to happen more often than not) we swing around and pick it up with a dip net over the side.

This afternoon, the girl with the rifle (who's one of my roommates) got off a good shot, so we have a sample from one of the three whales. They'll take it back to the lab and analyze its genetics to learn about the population structure of these magnificent beasts.

October 11, 2006

The 9th was an extraordinary day for sightings! I've not had time to write about it until now, but the evening net tows provided a really exceptional animal that I've never seen alive before: a paper nautilus, genus Argonauta. Strange as cephalopods are, argonauts would definitely be in the running if there were a contest for the strangest. The females are quite small--this specimen was thumb-sized--and the males are an order of magnitude smaller than that. Much of the male's mass is one enormously enlarged arm that is used for sperm transfer; it actually detaches from him at the time of mating and swims into the female's body cavity. When these arms were first discovered, they were thought to be parasitic worms.

Not to be outdone as far as strange reproductive habits go, the female uses two modified arms to secrete a shell, in which she lives and broods her eggs, once they are laid. The shells look superficially similar to those of the nautilus in structure, but argonaut shells are much thinner and more delicate. While the nautilus is permanently attached to its shell (it would be difficult to say if the animal is part of the shell or the shell is part of the animal), the argonaut can crawl freely in and out. Ours did this, once we took her out of the cod end of the net tow and put her in a little dish, and I caught it on film. She was beautiful, fragile, perfect.

After the initial discovery, filming, and photography, my net tow companions left me to my evening's work: sorting the plankton tow for squid paralarvae, then processing the squid that were jigged earlier in the evening. Usually the only people I see for the rest of the night are the crew members on duty, who walk regular rounds of the ship to check for fires, drownings, what have you. On this night, word of the argonaut had been passed around, and every crew member who walked through the lab wanted to see it. It was fun to have something to show off.

After sorting the plankton tow and extracting any squid that I find, I freeze the rest; it goes to another researcher somewhere. Then I trot outside and down to the lower deck where I finish with any squid that were caught earlier in the evening. It's a much more exciting venue for dissection that I was used to on the New Horizon. Back on that June cruise, the ship was stopped, the sea was calm, the lights were on, and there were plenty of other people around. But out here everyone else is in bed, the lights have been turned off, and the ship is hurrying along through the whitecaps. On a cloudy night, which is what we've been having, there's no way to tell the sea from the sky. As I stare out I can see only white foam rising and falling at the side of the ship, and beyond that, blackness.

At that point I usually give the obligatory late-night shiver and turn back to the squid on my dissection table (long since killed, quickly and humanely). I remove the stomachs, to study what they are eating and where they fit into the local ecology, and pieces of tissue for genetics, to find out how closely related they are to the squid in Mexico and California. On the night of the 9th, I also removed the gonads of a mature male and female squid and artificially fertilized some eggs so that I can study development and behavior of baby squid.

October 12, 2006

We had an orca sighting yesterday. While I was sitting in the lounge catching a few minutes of Harry Potter, the announcement was heard: "We have killer whales right off the bow, very active, breaching!" So of course we all raced outside, and of course by then there was nothing to see.

But we waited, breathing the fresh air and watching the last colors of the sunset fade from the sky, and then there they were, off to port. They were beautiful! I didn't see any full breaches but I saw a lot of them above the water, and I saw at least one tall, narrow fin of a male orca. Our chief scientist tried a long shot with a crossbow, and didn't get a successful biopsy, but as he very correctly pointed out, "You can’t get a sample if you don't shoot."

(to be continued)

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