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acidification

Giving oceans a fighting chance

Mary Barton-Dock's picture

Last week I went swimming with manta rays, sharks and dolphins along some of the world’s most spectacular reefs. Well at least, it felt like I was swimming among them. With my special 3D glasses on, it was as if I was flying across coral atolls, plunging through clouds of jellyfish and darting in and out of brightly colored corals alongside hundreds of thousands of tropical fish.

In a new film by Luke Cresswell and Steve McNicholas – The Last Reef 3D: Cities Beneath the Sea – viewers embark on a worldwide journey to explore coral reef habitats from Palau and French Polynesia in the Pacific to the Bahamas in the Caribbean.

As visually stunning as the film is, it carries a very sobering message: human activity is having a significant negative impact on the world’s oceans.

Many of us who work on climate change and oceans have known about the threat from ocean acidification and warming for a long time. Increasing carbon dioxide emissions have resulted in rising surface and air temperatures. Moreover, ocean acidity is rising owing to an increased absorption of carbon dioxide from the atmosphere. Increasing acidity levels in turn make it harder for corals to grow and for shell-forming animals like mussels to build their protective housing, leading to knock-on effects of biodiversity loss in ocean called “dead zones”.

The movie’s message is reinforced by a recent report published in Science Magazine which says the oceans are acidifying at a pace not seen in 300 million years. Historically, ocean acidification has led to mass extinctions. What makes today’s situation particularly alarming is that the rise in CO2 is not due to volcanic eruptions or other natural occurrences but is the direct consequence of human behavior over the course of the last century or so.