Overfishing or warming sea levels? There seem to be more jellyfish in the oceans and while they've been annoying summer beachgoers since time immemorial they are also capable of interfering with electricity generation outlets.

Al Jazeera English picks up some of the story:

The Daily Mail reported on July 6 how jellyfish forced the shutdown of the Orot Rabin power station in Israel.

A week earlier, both reactors at the Torness nuclear power station on the Scottish coast were shut down because of a sudden influx of jellyfish.

That was far from the first time that nuclear reactors have been shut down because of marauding jellyfish, as this analysis from Discovery News explains.

But there is also evidence that jellyfish are able to thrive in ocean Dead Zones where other marine life cannot, hence a disproportionate increase in their presence. Here is a presentation from the US National Science Foundation which paints a vivid picture on the rising presence of jellyfish in our oceans.

Point six of their presentation: "Four hundred vast Dead Zones in world oceans are too polluted for almost all life except jellyfish."

The International Year of the Dolphin begins on a poignant note. Last month, the Yangtze Freshwater Dolphin - the baiji (Lipotes vexillifer) - was declared to be almost certainly extinct.

A victim of the long-term poisoning of the Yangtze River.

The baiji is the first species of cetacean to have become extinct in modern times, and it's the first large mammal to disappear as the direct result of man's pillage of the Earth's natural resources.