zondag 17 juli 2011

Kwallenplaag bedreigt Israelische zwemmers - en electriciteitsvoorziening

Toen ik eind maart/begin april in Israel was zag ik ze al, vooral in Netanya. Ik vroeg het even na bij de tourist office, en nadat de medewerkster begreep wat ik bedoelde reageerde ze hoogstverbaasd, nee nooit van gehoord, kwallen, hier, op het strand? Maar ze wou de strandautoriteiten wel even bellen om te vragen of ze gevaarlijk waren, nadat ze zei dat je toch in zeewater van 18 graden sowieso niet kunt zwemmen. Helaas waren die er niet, maar uit onderstaand bericht begrijp ik dat ze gemeen kunnen bijten. Eerder had ik eens van iemand gehoord dat ze vooral in juni actief zijn. En dat terwijl ik onlangs nog droomde van de mooie Israelische stranden bij 30 graden, in plaats van het wisselvallige weer dat wij op onze vakantie daar hadden, en het takkeweer nu in Nederland.


Jellyfish scourge threatens Israeli swimmers - and electricity
Ronen Zvulun / Reuters

By Paul Goldman, NBC News Producer

TEL AVIV – During the hot summer months, Israel has always been synonymous with beautiful sandy beaches and swimming in the warm salty waters of the Mediterranean Sea – but not anymore.

It's now a common sight to see scores of dead, gray jellyfish covering the beaches’ white sand while kids poke them with sticks. It's even more common to see bathers running away from the water with big red sting marks.

More than 200 million jellyfish, known here as “Meduzot,” have been attacking Israel, and there is not much anyone can do about it. The jellyfish are an invasive species called Rhopilema Nomadica that originally migrated from the Red Sea.

They're coming here for one reason: They have few natural enemies lurking in these waters. The sea turtle is one such enemy, but massive construction along the Israeli coastline has devastated the turtle nesting habitat, leaving a paradise for the jellyfish. 

Dr. Dror Angel, who works at the Department of Maritime Civilization at the University of Haifa, says the problem of jellyfish is only increasing. "People bathing get stung, and for the fishermen it's a disaster, they catch them in their nets. And of course the electric plants suffer as well.”

Seawater is used to cool the turbines that supply most of the electricity in Israel.

"When we suck the water, we also suck the jellyfish,” explained Rafi Nagar, the chief maintenance officer at the Israel Electric Corp. near the town of Hadera. “And if we let them go through the filters, they can cause the plant to shut down, leaving millions of Israelis without electricity.”

Nagar has been working 24/7 to combat the enormous number of jellyfish.

"It's a very difficult problem," he said. "In the last three days, we pulled out 100 tons of jellyfish from our filters."

Nagar's crew has been nicknamed the “Jellyfish Busters.” They wear special goggles, rubber gloves and long-sleeve shirts and pants to help them protect themselves from the stings. They use long poking iron sticks to pull the jellyfish off of the filters, piling them into huge canisters. Nagar says that in his 33 years at the electric company he has never seen anything quite like this.

Alon Levi, a veterinarian who volunteers at the Israel Marine Mammal research center, said sailing in the Mediterranean last weekend was like "sailing in a soup of jellyfish.” But it’s not just difficult for swimmers and sailors; the explosion of the jellyfish population affects the larger eco-system.

“It's very sad since they eat small crabs and fish," said Levi.

Angel says we need much more information and research on the life of the jellyfish in order to find ways to cope with them.

One thing we know is that every female jellyfish lays 300,000 eggs – making it an almost impossible battle.

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