Jellyfish: The Cockroaches of the Oceans

The New York Times reported last week that beach goers should scratch deadly sharks from their worry lists, since there was only one fatal shark attack worldwide in 2007, but “just when you thought it was safe to go back in the water,” the Times warned us of a different menace in the water: jellyfish.

Anyone who has had an encounter with a jellyfish knows that jellyfish are blob-like and docile, though potentially dangerous if you brush against the wrong type or encounter them in large swarms.  Today, swarms are becoming more common, and according to jellyfish expert Josep-María Gili, their new and increased presence in coastal areas is the ocean’s form of a black spot: a signal of mutiny.

Why? The New York Times christens jellyfish the “cockroaches of the open waters,” a reference to their ability to survive in even damaged and otherwise unviable conditions.  Thus, more jellyfish are an ominous sign of deeper problems, such as:

“…severe overfishing of natural predators, like tuna, sharks and swordfish; rising sea temperatures caused in part by global warming; and pollution that has depleted oxygen levels in coastal shallows.”

Of course, if choosing between swimming with the average jellyfish versus a great white shark, the jellyfish would be the easy pick; jellyfish only sting when they bump up against something warm, rather than actively hunting down and preying on humans.  Furthermore, only some jellyfish have venom that is lethal on contact.  Still, the sting of non-lethal jellyfish can be fairly painful, and the chances of getting stung are magnified when one talks about swarms rather than just the occasional jelly.

The jellyfish problem is becoming so severe that in places like Barcelona, Spain, blue flags warning of jellyfish are joining the traditional red and yellow flags that warn of risky currents.  Will this phenomenon become a way of life as the health of the oceans declines?  Will frustrated fishers get used to having nets filled with more jellies than fish?

Or, will scientists and policymakers work together, responding to jellyfish like a symptom of an underlying illness?  By monitoring the jellyfish populations and responding to the deeper issues of pollution, global warming, and overfishing, we can help our world’s bodies of water to heal and to naturally respond and remedy the jellyfish infestation.