A nuclear power plant in Shimane, Japan, was closed down recently as millions of jellyfish clogged the reactor's cooling system.

Seems weird, but true. A explosion in Jellyfish population has led to the closure of at least four nuclear reactors in Japan, Israel and Scotland.

Recently, two reactors at Torness power station, operated by EDF, in Scotland had to be shutdown as the seawater used as coolant was inundated with jellyfish.

Though, these nuclear plants have filters to block the marine life, the latest invasion is proving too much for the filters to handle. Jellyfish got into the reactors and blocked its cooling system, prompting operators to shut down the reactors until the filters are cleared.

Even scientists are unable to give a clear explanation to the ongoing jellyfish bloom, which occurs mostly during the summer and spring months. Some scientists say rising sea temperatures caused by climate change may also contribute to jellyfish blooms, because many species of jellyfish are better able to survive in warmer waters.

However, this year is one of the coolest years in recent history, so the surge of jellyfish population explosion this summer is mystifying.

Meanwhile, scientists have little quantitative data of historic or current jellyfish populations.

Check some amazing shots of jellyfish invasions below: