Ctenophore
Image George Matsumoto © 1989 MBARI
Click the image above to launch an interactive slideshow
(Opens in new window)
After heading out a dozen or so miles into the bay, the MBARI researchers will release the ship’s submersible mini-me, the remote-operated Ventana. Tethered by a cable a half mile long, the vehicle will deliver a kettledrum-size unit called the Midwater Respirometry System (MRS) to the ocean floor, where it will record the respiration of the creatures it collects in its chambers. The depths of Monterey Canyon are, by Robison’s reckoning, the most studied part of any ocean in the world, and the Ventana, which is coming up on its 3,000th dive, has been in use here for two decades. Even so, scientists are still finding new animals there all the time. As for the jellies, Robison says that we’ve “grossly underestimated” their complexity, their numbers, and their fundamental importance to everything else living in the sea. In fact, he now believes that jellies make up at least a third of the oceans’ entire biomass.
The MBARI team’s principal task today is deploying the device that will measure the jellies’ breathing. Kim Reisenbichler, who is managing the experiment, explains that the MRS contains four separate chambers. After the experiment is lowered, the pilot maneuvers the MRS so that a jellyfish or other marine creature, as well as seawater, enters a chamber. Then the chamber’s door is closed. Sensors in the chambers measure the animals’ breathing by analyzing changes in oxygen concentration in the captured water.
When Reisenbichler began working with Robison 28 years ago, most marine biologists still trawled the ocean with nets. What they drew up often yielded no more than a lot of mush. Even now, in the age of submersibles, many of the jellies caught below 3,000 feet are so delicate that they do not survive to the surface or, if they do, they get damaged during transfer from one container to another.
While new methods of data collection are changing the kinds of questions scientists can ask about these delicate invertebrates, ultimately it is the jellies’ gaudy, Andromeda Strain–ish proliferation—the very thing that makes them such objects of fascination now—that will most likely speed up the study of them. As humans put stress on the habitats of more complicated marine creatures, Robison explains, “jellies, because they are relatively simple, cheap to build, and can reproduce very quickly, can respond to negative impacts on other kinds of animals by rushing in to fill their niche.”
So I’m compelled to ask: When it comes to global warming, are jellyfish the canaries in the mine shaft?
“No!” he answers, making me realize I’ve chosen a metaphor that’s right and wrong all at once. “They’re not dying; they’re moving in! They’re diggin’ it!”
With pilot D. J. Osborne working the controls from an electronic “belly pack” he’s got strapped to himself, the Ventana finally rises off the deck of the Point Lobos and gets lowered over the side. Reeling out a graceful curve of yellow cable, D. J. pushes the submersible a fair distance away from the ship before submerging it beneath the bay. In the ship’s control room, the team tracks what the rapidly descending Ventana has in front of its lens on a bank of video monitors. The image quality is as sharp as anything in the LCD aisles at your local Best Buy. White dots rise like champagne bubbles through the blue water, indicating the submersible’s downward progress. “Marine snow,” Reisenbichler notes, “a mucuslike substance filled with bacteria and fecal pellets.”
A plump, red jelly, with tentacles like the fringe on an ancient tearoom lampshade, enters the picture.
“Want to catch him?”
“We can always release him.”
“He’s pretty porky.”
“Put him in apartment three.” From there, for the next two days, the MRS will listen to him and some other new captives breathe.
“We’d better plant this sucker,” Robison says, and in another minute or two we’re just where we have to be to detach the MRS from the Ventana. The greenish-looking ocean floor, on which a starfish sits, suddenly rises into view. The base of the MRS stirs up the sand, and a curious sablefish collides with the device, provoking laughter.
Craig Dawe, the Ventana’s chief pilot, manipulates a mechanical claw to pull the cables off the automated instruments being left behind. Before our departure, the Ventana’s camera zooms in on the detached MRS, recording the exact coordinates we’ll return to, two days from now, to retrieve it. With that done, it’s time to reel the Ventana back up through the water to the Point Lobos. As it ascends, its camera notices a long line of yellow ink, and the control-room team starts to track a squid that’s eating a hard-bodied fish. The head of the prey is trapped inside the squid’s tentacles like a salmon that’s leapt? into the mouth of a bear.
