Warmer waters "good for coral growth"


Doing OK?

It’s rare to find anyone with a good word to say about warmer temperatures. If you believe the media and the consensus boys, the global temperature we had in year x (where x is any random year you care to choose) was the “right” one for the planet, and any change, whether up or down, is invariably bad.

We’ve already seen that temperatures heading down generally causes more hardship, but why should a modicum of warming immediately be bad? There is no “right” temperature for the planet – such a construct is pure alarmist fiction.

So it is interesting to read that a new study in Science (peer-reviewed, for what that’s worth these days) shows that corals around Australia are thriving in slightly warmer temperatures:

A GOVERNMENT-RUN research body has found in an extensive study of corals spanning more than 1000km of Australia’s coastline that the past 110 years of ocean warming has been good for their growth.

The findings undermine blanket predictions that global warming will devastate coral reefs, and add to a growing body of evidence showing corals are more resilient than previously thought, up to a certain point.

The study by the commonwealth-funded Australian Institute of Marine Science, peer-reviewed findings of which are published in the leading journal Science today, examined 27 samples from six locations from the West Australian coast off Geraldton to offshore from Darwin.

At each site, scientists took cores from massive porites corals – similar to a biopsy in humans – and counted back to record their age in much the same way tree rings are counted. Although some cores extended back to the 18th century, they focused on the period from 1900 to 2010.

The researchers found that, contrary to their expectations, warmer waters had not negatively affected coral growth. Quite the opposite, in fact: for their southern samples, where ocean temperatures are the coolest but have warmed the most, coral growth increased most significantly over the past 110 years. For their northern samples, where waters are the warmest and have changed the least, coral growth still increased, but not by as much.

“Those reefs have actually been able to take advantage of the warmer conditions,” said Janice Lough, a senior AIMS research scientist and one of the study’s authors.

Maria Byrne, a professor of marine biology at Sydney University, said after reading the paper that its findings “made perfect sense”. “Temperature rules metabolism, so it’s a no-brainer that if you get more temperature you will get more metabolism.”

She compared the findings to studies of sea urchins, where higher temperatures had been shown to offset the negative effects of ocean acidification, and to commercial aquaculture farms, in which some organisms are deliberately raised in warmer water to increase their growth rate.

The key question is how warm the water can get before the positive effects are reversed.

Lab studies have typically measured the effect of short-term, rapid changes in temperature and water chemistry; these mimic, for example, coral-bleaching events that are known to be devastating. Much harder to measure are the long-term effects of gradual warming, such as is caused by climate change.

A recent paper published in the journal Nature Climate Change, reported in The Australian, showed Zooxanthellae – the symbiotic organisms that live inside corals – can adapt much better to warming water than was previously thought [see here for ACM’s post on this – Ed] It is also known corals can, to a degree, change their Zooxanthellae with changing conditions. (source)

The Science abstract can be found here, a quote from which is set out below:

“In situ studies have documented alarming recent declines in calcification rates on several tropical coral reef ecosystems. We show there is no widespread pattern of consistent decline in calcification rates of massive Porites during the 20th century on reefs spanning an 11° latitudinal range in the southeast Indian Ocean off Western Australia.”

UPDATE: Scientific American spins this into the following headline:

 “Temperatures – not acid – could cook coral to death”

No, really, “cook coral to death” – that’s what it says. Check the link.

"Sea cucumber poo" helps fight climate change


There's a sea cucumber pooping in this photo somewhere

From the You Couldn’t Make This Stuff Up Department. Yes, ladies and gentlemen, the award for Most Bizarre Thing To Allegedly Help Climate Change goes to:

Tropical sea cucumbers and their faeces could save coral reefs from the harmful impacts of climate change, scientists have found.

Scientists at One Tree Island, the University of Sydney’s research station on the Great Barrier Reef, say sea cucumbers reduce the impact of ocean acidification on coral growth.

“When they ingest sand, the natural digestive processes in the sea cucumber’s gut increases the pH levels of the water on the reef where they defecate,” Tree Island director professor Maria Byrne said. (source)

Look, I know they’re trying to be nice here by giving the sea cucumber some credit in all of this, but really, the sea cucumber doesn’t do anything except crimp off a few lengths now and again. It’s the shit that does the job. Bravo.

Coral reefs "gone in sixty seconds"


Time's up

Well, sixty seconds in a geological context – actually by 2050. Coral reefs have been on the planet for aeons, but one extra molecule of CO2 out of every ten thousand in the atmosphere caused by your SUV is enough to finish them off in less than 40 years:

The world’s coral reefs could be wiped out by 2050 unless urgent action is taken to stop threats posed to the “rainforests of the sea” by everything from overfishing to climate change, a report warned Wednesday.

Warmer seas caused by global warming; ocean acidification blamed on carbon dioxide pollution; shipping, overfishing, coastal development and agricultural runoff all pose a threat to coral reefs, which hundreds of millions of people depend on for a living, says the report.

“Threats on land, along the coast and in the water are converging in a perfect storm of threats to reefs,” Jane Lubchenco, administrator of the National Oceanic and Atmospheric Administration (NOAA), said at a news conference in Washington to launch the “Reefs at Risk Revisited” report.

According to the report, which follows on from an earlier study on the health of the world’s coral reefs, more than 90 percent of reefs will be threatened by 2030 and nearly all reefs will be at risk by 2050 unless action is taken now to reduce the threats.

“Local pressures” on reefs, including overfishing, coastal development and pollution, pose the most immediate and direct threats to the world’s reefs, threatening more than 60 percent of the colorful sea ecosystems.

The impacts of climate change — a “global threat” to reefs — is compounding the local pressures.

“Warming seas have already caused widespread damage to reefs, with high temperatures driving a stress response called coral bleaching, where corals lose their colorful symbiotic algae, exposing their white skeletons,” the report says. (source)

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