Tilapia removed from a Queensland waterbody. (www.mdbc.gov.au: Amanda Dimmock)THIS frightening scenario of mass extinction from several directions is one of the major reasons I critique religious fanaticism, because many years ago I kept butting heads with anti-environmentalist Christian fundamentalists who didn’t care about “this stinkin’ earth.”  In this case, I truly hate to be right.

Scientists fear mass extinction as oceans choke

Australian scientists fear the planet is on the brink of another mass extinction as ocean dead zones continue to grow in size and number.

More than 400 ocean dead zones – areas so low in oxygen that sea life cannot survive – have been reported by oceanographers around the world between 2000 and 2008.

That is compared with 300 in the 1990s and 120 in the 1980s.

Professor Ove Hoegh-Guldberg, of the ARC Centre of Excellence for Coral Reef Studies (CoECRS) and from the University of Queensland, says there is growing evidence that declining oxygen levels in the ocean have played a major role in at least four of the planet’s five mass extinctions.

“Until recently the best hypothesis for them was a meteor strike,” he said.

“So 65 million years ago they’ve got very good evidence of the cretaceous exctinction event.

“But with the four other mass extinction events, one of the best explanations now is that these periods were preceded by an increase of volcanic activity, and that volcanic activity caused a change in ocean circulation….

“Just as we are seeing at a smaller scale today, huge parts of the ocean became anoxic at depth.