Jellyfish could prevent the world's sixth mass extinction

As the world's oceans become depleted of their top-level predators; tuna, sharks, swordfish, Pacific salmon and dozens of others, Mother Nature is scrambling to fill the ecological holes with something a little better suited to withstand the greedy, vicious, and opportunistic nature of man. That something is jellyfish!

Jellyfish? Yes, those harmless, transparent bits of jelly that beach goers see floating lazily in tidal currents, or washed up on shore by the wind. I know it's hard to believe the slimy things are better suited for survival than sharks. But they are!

They have already survived five mass extinctions, including the last one, 85 million years ago. The one that killed off all the dinosaurs. I'll admit that some of the more than 2,000 species may not last through the next extinction, but plenty will. As for being harmless, they can be quite dangerous. Rather than being docile, they are actually meat-eating predators. One species of jelly actively hunts its victims and, next to man, is the deadliest creature on the planet.

In 2007, the sea for 10 miles around Ireland's only fish farm shone eerily with a red and purple glow from a mass of Mauve stinger jellyfish 35-feet deep as they drifted into the nets of the salmon pens and asphyxiated and stung to death every last one of more than 120,000 adult fish over a 7-hour period.

In Australia and the Philippines, between twenty and forty people are killed by box-jellies every year. One variety, the thimble-sized 'sea wasp' has enough venom in one tentacle to kill a full-grown man in three minutes. They kill more people than all other predators combined,

The giant 400-pound Nomura's jelly in the Sea of Japan is no slouch either. With a diameter of six feet, and tentacles 30-feet long, it is proving to be a very formidable foe, killing eight people since the mid-nineties – just a couple fewer than have been killed by sharks in the same period – and crippling the mighty Japanese fishing fleet.

Most jellyfish have no brain, heart, or other organs generally associated with fish and mammals, but some have some very enviable characteristics. The turritopsis dohmi, for example, is biologically immortal. The box jelly has four brains, four hearts, and four sets of six eyes. All species can live in very low-oxygen, highly pollluted conditions. At least one species doubles its size daily and matures in two weeks. After reaching adulthood, it lays 1,200 eggs per day for its entire three month lifetime. Most spawn when threatened or killed, thus every jellyfish death increases the total population.

In addition to being one of the most interesting and mysterious life forms on earth, jellyfish are of special importance because, by interfering with world fisheries, they may also be the last hope of survival for hundreds of high-level predators.

Stay tuned and I'll tell you why I believe the spread of jellyfish is a good thing.