A scientist doesn’t often fret that his research subjects might clog the ventilation system of his office. But Chad Widmer, 37, a senior aquarist at the Monterey Bay Aquarium just south of San Francisco, studies jellyfish, and along the world’s coasts, jellies seem to be exploding in size and number, pulsing through waters they haven’t ventured into before. In places like the Gulf of Mexico—where 60-pound blobs with 80-foot tentacles have appeared in recent years—the increasingly abundant creatures provoke mostly fear and disgust. To Widmer, though, everything about the jellies is fascinating. (He has a crystal jelly, the Aequorea victoria, tattooed on his left leg.) He especially wants to be able to predict their “blooms,” sudden spurts in the jelly population that can wreak havoc on fishermen’s nets or snarl a building—like the Monterey Bay Aquarium—whose operations depend on running seawater through it.
The aquarium stands on a part of the waterfront where John Steinbeck famously described boats brimming with fish. Within a decade of Cannery Row’s 1945 publication, though, the bay had been emptied of silver sardines, and now, a half century later, amid the jellyfish boom, something dire is happening to the bay once more. Over the past several years, Widmer says, salmon catches have “gotten worse and worse and worse,” while leatherback sea turtles, in order to find their food, have had to go “farther and farther offshore.” And the mola, a large sunfish that was once so abundant in Monterey Bay? “They’re just not here,” Widmer says. At first glance, even jellyfish would seem to be vanishing; in recent years the creatures have been more or less disappearing from the bay’s surface. Look deeper, though, and you’ll find a staggering diversity of these spectacular, tentacular creatures.
Along with the worries comes a rich set of scientific questions: Does the rise of the jellies (pdf) have something to do with the decline of the fish? What can jellyfish tell us about the health of the oceans? How will they fare as the oceans absorb more carbon dioxide from the air and become more acidic? Right now, no one knows. Across town at Monterey Peninsula College, Kevin Raskoff, who has investigated jellies in the Arctic, argues that for all their abundance, they are “probably the most alien life-form on the planet.” He still sees the animals as being, to a great extent, “a big black box. We know they’re there, but we don’t necessarily know what they’re doing.” Yet everything we have managed to learn about jellies in recent years “keeps pointing to how much more important they are than we thought,” Raskoff says. “There’s a long history of jellyfish really coming into huge numbers, big blooms, with a big effect on ecology, when you have perturbations to the system.” While perturbations can be part of a natural cycle, humans have been jostling the ocean ecosystem with dismaying gusto. We’ve been overfishing tuna and swordfish—some of the jellies’ predators—and the jellies seem to be responding.
At the Monterey Bay Aquarium Research Institute (MBARI), founded in 1987 by computer pioneer David Packard, veteran scientist Bruce Robison isn’t ready to make a primary-level link between jelly increases and global warming, but he’s certainly intrigued by the “second-, third-, or eighth-level connections.” Jellies, he says, “show us how the seas are changing, both naturally and in response to our own meddling.” We may not be putting jellies in charge of the oceans, but “we are giving them their shot at playing a bigger role by wiping out much of their competition,” he says. It’s their “broadly adaptable physiology” that will allow them “to outcompete more complicated animals for niches that become available because of warming, or acidification, or any number of reasons.”
So don’t blame the jellies. However many intake valves they clog or swimmers’ legs they sting, jellies aren’t turning the oceans acidic or warming them up. We are.
