Moon jellyfish, Aurelia aurita (Photo Credit: Luc Viatour)
Moon jellyfish invasion forces nuclear reactor shutdown
Thursday, October 03, 2013, 02:30 (GMT + 9)
A giant bloom of moon jellyfish (Aurelia aurita) on the Swedish coast of the Baltic Sea forced Sweden’s biggest nuclear reactor to stop operating after the invasion blocked the cooling water inlet.
Anders Oesterberg, a spokesman for the nuclear power plant told Bloomberg that the 1,400 megawatt Oskarshamn-3 has been forced to close down because of jellyfish clogging the pipes that bring in cool water to the plant’s turbines.
Speaking from Oskarshamn, Oesterberg remarked: “This situation is caused by a huge amount of jellyfish, just one is definitely not enough to cause problems. The last time this happened was in August 2005, when we had to shut down Oskarshamn-1 because of a jellyfish invasion.”
According to German environment protection group BUND, global warming and overfishing is mainly responsible for this extraordinary occurrence. These alterations in the world’s climate has meant more plankton has grown in the Baltic Sea and this, in turn, has led to a bloom of jellyfish, disrupting the ecosystem by greatly increasing its numbers.
Moon jellyfish belong to the genus Aurelia and have pale, translucent bodies for which they are popularly named. For the most part, they inhabit the coasts of Europe and North America.
“The aim is to slowly start a couple of the cooling water pumps in order to drain the inlet pond of jellyfish and see that they are all distributed back to the sea,” Oesterberg said. “When the amount of jellyfish is reduced to an acceptable level, we will be able to restart production.”
Oesterberg pointed out that there was no risk of a nuclear accident because of this incident. It was the moon jellyfish which were at risk instead, since they could be killed by pressure from the filtration rather than from contact with any boiling water.
"It's true that there seems to be more and more of these extreme cases of blooming jellyfish," said Lene Moller, a researcher at the Swedish Institute for the Marine Environment. "But it's very difficult to say if there are more jellyfish, because there is no historical data."
The scientist explained that the moon jellyfish, in particular, is a species that can grow in extreme areas, affected by overfishing or having poor conditions.
Jellyfish have been responsible for similar situations in Scotland. In 2011, both NexEra in Florida and Electricite de France SA had to halt their operations due to jellyfish invasions.
By Gabriela Raffaele