Dominion of the Jellyfish: Slimy Invertebrates Taking Over Our Seas

Beautiful, baffling, and very strange, jellyfish are something of a mystery. They have no head, no heart, no eyes, no bones, and strangest of all, no brain. Still, they float around the seas with their stinging tentacles, some of the most effective predators in the world.

In the past, jellyfish have seemed like more a passing annoyance than creatures to worry about. A sting might ruin a weekend at the beach, or a mass of the incoming creatures might scare tourists out of the water. But things are changing. They can be incredibly dangerous, and one breed in particular, the box jellyfish, is one of the most poisonous creatures on Earth. And these strange, dangerous creatures are taking over our seas.

In the past, jellyfish "swarms" were few and far between. There would be years with more jellyfish than others, but most beaches were fairly safe. They were generally no more than a passing inconvenience.

But human activity has changed the way that they move and breed. Over-fishing and polluting the seas has left whole swaths of "dead zones" in our oceans. With rising water temperatures and little competition for food, these areas have become the perfect breeding ground for jellyfish. And in the last few years, these creatures have transformed from a passing annoyance into a real danger. And a real worry for ecologists. Jellyfish are increasing in number and it's happening all over the world.

Unswimmable Australia. Australia is home to the box jellyfish, a tiny, deadly bugger that claims several lives every year. Worse, Australia is also home to it's tiny, equally deadly cousin, the Irukandji. This little guy looks innocent, and being stung by one is no worse than a slightly painful irritation-- a bit of heat, and then it's gone. Hours later, however, more serious symptoms (such as intense head and backaches) begin to appear. By then, it is often too late, and many victims die.

In the past, about 30 people a year would fall victim to this tiny little jellyfish. But in 2008, that number has surged up to 200, with several deaths and no explanation for the increase in numbers of this deadly little jelly.

Giant Jellyfish in Japan. In the Sea of Japan there have always lived a very few giant jellyfish, called Nomura's. Growing to huge sizes and weighing up to 200kg (about 440 lbs.), these guys would "bloom" (or breed into adults) only once every several decades. Rare, these jellies were only of a passing interest.

But in the last year, big guys have begun taking over the Sea of Japan, crippling the fishing industry. They get caught in fishermen's nets, crushing the fish, breaking nets, and damaging fishing boats. And attempts to kill them only releases more eggs, breeding more of these giant creatures.

Overtaking Southern Africa. The spot that fish have held in the food chain in southern Africa has been taken over by jellyfish. In the last several years, the area has experienced the largest invasion ever recorded, when they are in huge numbers like this they burst fishing nets. In some areas they have almost completely overtaken fish, causing the fishing industry there to cave in. And there's no solution in sight.

A Stinging Mediterranean Sea. While the Mediterranean has always had its fair share of jellyfish, disturbing summer swimming in Spain, Italy, and France, invasions in the area used to take place only once in 7-10 years. But all of that is changing. With warmer, saltier waters, jellyfish are breeding in the Mediterranean in record amounts. And every summer, they're swarming in greater and greater numbers, injuring tens of thousands of tourists and causing several deaths. And all evidence points to them becoming regular summer visitors to the Mediterranean for many years to come.

While increasing numbers of jellyfish may seem like a minor concern, their overwhelming presence is causing disquiet among ecologists. All over the world, fishing and tourism industries are suffering... and the problem is only getting worse. The question is, when they have finished taking over the ocean, will there be any more room in it for us?

This article was written by Shawn Wilson, a member of the customer support team at Datepad, where internet dating is always free. Datepad has a massive directory of informative dating articles along with a great list of dating site reviews on their dating blog.