Thursday, 8 August 2013

Shifting the truth southward

The Sydney Morning Herald featured an article a few days ago titled Marine life on the move.
The first global snapshot of marine life shifting under climate change has found it is on the move towards the poles at a rate of about seven kilometres a year. Fish and other marine creatures are seeking cooler habitat much faster than terrestrial life, according to an international study published in the journal Nature Climate Change.
Can't stand the heat, huh? Not exactly - not at all exactly in fact, as the article actually informs us, but right at the end of course, well to the south, where the truth has shifted to, well after the preceding and misleading statements have sunk in.
"The leading edge or 'front line' of a marine species distribution is moving towards the poles at the average rate of 72 kilometres per decade," Dr Poloczanska said. "This is considerably faster than terrestrial species moving poleward at an average of six kilometres per decade . . . despite sea-surface temperatures warming three times slower than land temperatures."
So it's the "leading edge" of species distribution moving poleward, not the entire distribution. In other words, the "trailing edge" is staying where it was, and the species are extending their range. They're not moving away from warmer water "seeking cooler habitat", but extending into previously cooler waters.
Dr Poloczanska, of the University of Queensland, and 18 international colleagues found no doubt about who was responsible for the greenhouse gas-related warming of the ocean's upper layers. "Global responses of marine species revealed here demonstrate a strong fingerprint of this anthropogenic [caused by humans] climate change on marine life," the paper said.
Dr Poloczanska said in Australia's south-east, tropical and subtropical species of fish, molluscs and plankton were shifting much further south through the Tasman Sea.
But they're not "shifting much further south through the Tasman Sea", they're being found further south, as your study actually found, Dr Poloczanska.
A 2010 CSIRO study found that warm surf-zone species such as silver drummer were more abundant, while the range of others such as snapper and rock flathead has increased.
In the Indian Ocean, a southward distribution of seabirds has been detected, as well as a loss of cool-water seaweeds north of Perth.
Several studies in recent years were reported as indicating a "poleward shift" of species, whereas in every case, a closer examination reveals not a shift, but an extension of range. Shifting the truth, to fit an agenda. Good science distorted by a totally misleading summary, and by one of the authors too.

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