Primordial. Deadly by nature. Unsuspected. Relentless. And, preferably, repulsive. That’s how I like my horror-movie threats.
The jellyfish, 550 million years old, has of late taken over vast regions of oceans stripped of competitors by overfishing, or oxygen-depleted by agricultural chemicals, or warmed by increasing air temperatures to levels toxic to what few competitors it still has.
Like the giant irradiated ants in ‘Them’ (1954), which I wrote about here, human actions have unleashed jellyfish from their niche. This time, however, the threat is real.
Tim Flannery’s fine essay, ‘They’re Taking Over!’ in the New York Review of Books for Sept. 26 does not disagree. The polymath and former (as of last week) Chief Commissioner of the Australian Climate Commission is reviewing Lisa-ann Gershwin’s Stung! On Jellyfish Blooms and the Future of the Ocean (Univ. of Chicago, 2013).
The Portugese Man of War most ocean swimmers have heard enough about to stay clear of its long stinging tentacles. But the Irukandjis jellyfish, ‘peanut- to thumb-sized’ makes its human victims wish they were dead, if the ‘extreme high blood pressure’ their sting causes doesn’t kill them.
First identified in Queensland in 1967, they have spread to Cape Town and Florida.
Ships have helped extend the range of jellyfish by means of seawater ballast taken on after unloading cargo and expelled at the port where they next take on goods. Jellyfish have also taken the measure of vast ships. Says Flannery,
On July 27, 2006, the USS Ronald Reagan, then the most modern aircraft carrier in existence, was docked in the port of Brisbane, Australia. New Zealand had earlier banned the entry of nuclear-powered ships, and many Australians felt it might be prudent to follow their lead. So when the commander of US Naval Air Forces announced that an “acute case of fouling” had afflicted the giant vessel, people took notice. Thousands of jellyfish had been sucked into the cooling system of the ship’s nuclear power plant, forcing the closure of full onboard capabilities…. Local fire crews were placed on standby, and the citizens of Brisbane held their collective breaths as the battle between the navy and the jellyfish raged. In the end, they proved too formidable, and the ship was forced out of port.
These relics of the pre-Cambrian explosion of exotic life forms remain immensely strange. Flannery quotes Gershwin:
Jellyfish reproduction is astonishing, and no small part of their evolutionary success: “Hermaphroditism. Cloning. External fertilization. Self fertilization. Courtship and copulation. Fission. Fusion. Cannibalism. You name it, jellyfish [are] ‘doing it.’”
Later, Flannery notes, ‘One kind of jellyfish, which might be termed the zombie jelly, is quite literally immortal.’ After ‘death’, cells escape the rotting body, find each other and then form the jellyfish’s infant stage.
Like the Blob in the eponymous 1958 movie the jellyfish is inexorable. Flannery writes:
One of the fastest breeders of all is Mnemiopsis. Biologists characterize it as a “self-fertilizing simultaneous hermaphrodite,” which means that it doesn’t need a partner to reproduce, nor does it need to switch from one sex to the other, but can be both sexes at once. It begins laying eggs when just thirteen days old, and is soon laying 10,000 per day. Even cutting these prolific breeders into pieces doesn’t slow them down. If quartered, the bits will regenerate and resume normal life as whole adults in two to three days.
Just like the Blob!
Jellyfish are voracious feeders. Mnemiopsis is able to eat over ten times its own body weight in food, and to double in size, each day…. And they can be wasteful. Mnemiopsis acts like a fox in a henhouse. After they gorge themselves, they continue to collect and kill prey. As far as the ecosystem goes, the result is the same whether the jellyfish digest the food or not: they go on killing until there is nothing left….
Gershwin is not optimistic about humankind’s ability to control jellyfish. She says:
[When I started Stung:] …I underestimated how severely we have damaged our oceans and their inhabitants. I now think that we have pushed them too far, past some mysterious tipping point that came and went without fanfare, with no red circle on the calendar and without us knowing the precise moment it all became irreversible. I now sincerely believe that it is only a matter of time before the oceans as we know them and need them to be become very different places indeed. No coral reefs teeming with life. No more mighty whales or wobbling penguins. No lobsters or oysters. Sushi without fish.
Flannery closes, saying of Gershwin, ‘Her final word to her readers: “Adapt.”’