The Red Sea
By Jo Nova
Corals around the world stopped growing in 2000BC and the pause lasted two thousand years before they returned like the Phoenix.
Each polyp might be fragile, but coral ecosystems are apparently the couch-grass of the oceans.
A new paper rather puts the man-made panic about corals into perspective.
The most terrible events that could happen to corals have already happened, and the corals appear able to bide their time for two thousand years and return in all their glory.
The worst thing for the worlds corals is not rising seas but falling ones.
We panic over the odd bit of bleaching here and there, but it’s nothing compared to mother nature. The shallow edges of the oceans of the world are savage places. And the best place to study this mayhem is the Red Sea. Not only is it hot, but long, thin, deep, and it’s tectonically active too. In the depths of the last ice age, it was cut off from the Indian Ocean and the salinity rose to a death defying 47% at the Southern end, and 57% in the north. For thousands of years, the Red Sea was pickled.
When the world finally warmed and waters came back 18,000 years ago, baby corals had to travel 2,400 kilometers from the Gulf of Aden to get to Eliat, at the far northern end of the Red Sea, yet they easily did. And the seas kept on rising for thousand of years, and that was all fine and dandy, until disaster struck 4,000 years ago when the seas started to fall, and presumably those delicate polyps were left to bake in the sun.
Feldman et al, studied this phenomenon in the Red Sea and noticed that other scientists have already reported coral growth stagnated in all the major oceans at roughly the same time. For two thousand years there are almost no new fossil corals in any of the cores they drilled. Then somehow, the distinct coral communities that had thrived long before, all reappeared.
Imagine if seas were falling by a few millimeters a year today? The government funded scientists would be raging against the falling of the tide. Whole institutes would be established to move corals to baby nurseries, or special zoos, or to set up seed banks, or to wall off whole reefs. People would be dreaming up schemes to heat the oceans…
But like couch-grass, we couldn’t kill the corals off in the oceans if we wanted too.
Thanks to Kenneth Richard at NoTricksZone for recognising the importance of this paper:
In this study, we propose not just a local sea level condition causing specific reef turn-offs or hiatuses, but rather a global phenomenon of sea level fall. In light of our findings from Eilat and examining the reports from different locations around the globe (discussed above), we identify a global hiatus in reef growth between approximately 4000 and 2300 years BP (Figure 5). The available studies found almost no fossil corals dated to this time interval at sites across the Atlantic, Indian, and Pacific Oceans (Cortes et al. 1994; Dechnik et al. 2019; Gischler et al. 2008; Perry and Smithers 2011; Shaked et al. 2004, 2005, 2011; Toth et al. 2012),
FIGURE 5 | Reconstruction of global sea level—Compilation of radiocarbon dates from seven sites vs. mean below sea level (MBSL). Possible
global sea level curve is presented with demonstrated fall between ~4000–2300 years BP.
Reading the paper is like trawling through an epic biblical drama. Corals want to grow near the surface to harvest the sunlight, so as the seas rise, they just grow upward. When seas stabilize they spread outwards. But the Red Sea has steep sides and the corals can’t expand far. The reef they studied at Eliat at the far northern end, was 1 kilometer long, but only 20m wide. Then just when those delicate corals get settled, a tectonic upheaval blows it away.
(d) Pictures
of all seven cores extracted from the lagoon, reef flat and fore reef of the Nature Reserve in Eilat, and some of the coral species that have been found (e) A sketch of Eilat’s Nature Reserve coral reef with all seven extracted cores and their locations. Black arrows on core’s sides represent if were taken from the north (up) or south (down) jetty.
So Feldman et al drill all these cores, and find all the remnants of different species, but when they date the samples they discover there is a kind of Bermuda triangle of corals. All corals below a certain depth are 4400 years or older, and just above that they are 700 years old.
At some point the corals must have completely died, and been reseeded from a far distant area. Or a few remnants struggled on somewhere, and somehow they still came back.
FIGURE 2 | (a) Core lithology and coarse coral community structure of all seven cores from the Nature Reserve Eilat. 14C dates (calibrates year BP) as well as U-Th dates are presented at the right side of each core. Dates in red represent age reversals. The upper dashed line separate between recent samples and 4000 yr. dated samples. The middle part separates the 4000 yr. dates and the 5000 yr. samples. Everything beneath the lower line is 6000 yr. and older. (b) Age depth model for cores NR05, NR07 and NR10. Measured ages are marked by colored symbols and error bars (dR = −8 and uncertainty = 33). The model is the black line with error in matching color. Accordingly, the hiatus spans between ~4400 y cal BP and ~ 700 y cal BP.
Spare a thought for all those poor little polyps when the next real crisis comes and we get another Ice Age. Spare a thought for us, too..
REFERENCE
We couldn’t kill the world’s corals if we wanted to.
[]ED
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Yes, and the polar bears are just fine as well.
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So what happened to our GBR when SLs started to drop on our east coast about four thousand years ago?
We know that SLs today are about 1.5 metres lower than 4,000 years ago or at the end of the Holocene climate optimum.
Of course during the last full glaciation SLs dropped over 100 metres over most of the globe. And that last glacial maximum lasted for about 90,000 years.
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Spent a day* swimming in and around the Sinai Peninsula’s Blue Hole, down the arid desert coast from Eilat in the Gulf of Aqaba. The previous fortnight I’d been swimming above corals off Bali, Indonesia: tropical or desert, those resilient little polyps will grow anywhere they can (but not Scotland, quite a bit of snow but no corals there in ‘summer’).
Jo, free proofreading hint: if we wanted to, not ‘too’, plus world’s.
*1986
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A bit of “rock-doctoring” raises a whole slew of different questions. Marble is a metamorphi rock. Basically Limestone thet has been heated and compressed. Neither process likely to occur underwater, near the surface.
Limestone is generally compressed coral; compacted but not “heated”.
Corals of one sort or other have been endemic in “warmish” oceans for a LONG time.
But then we get to noticing that the crustal plates have been slowly tap-dancing all over the place for even longer, and they are still at it.
Where, relative to the “South Pole”, was the Australian Plate a few, (or more), million years ago? Crustal plates move, but not just laterally. various “lumps and bumps see them moving vertically as well
The planet is NOT preserved in aspic for all time.
The only reasonable “debate” has been between the “Gradualsts” and the “Catastrophists”; slow but steady change vs intermittent “outbursts” of major activity. Possibly BOTH have their place and time.
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Also this confirms the obvious reason for coral bleaching.
The Great Barrier Reef is about 2500km x varying but up to 250km. It is the size of Germany. It has geography, rivers, lakes, seas, topography and it is subject to rising and falling tides and storm surges and evaporation. It is a complex ecosystem. But if the water falls, the coral near the surface is exposed to the burning sun in the tropics. And dies.
That this should happen is not a mystery but obvious. The idea that it is caused by warming oceans is absurd. The reef covers a huge range in temperatures as it is aligned North/South and has its own oceans and ecosystems with warmer water on one side of the inner reef and half the planet of water 4km deep on the outer side. The opportunism of the activists is the only reason anyone suggests that a living structure which has been there from Roman times is suddenly under threat from an average temperature change of a degree? The real reason is in the many billions of dollars fixing something which doesn’t need fixing. Apparently all the planetary climate and ocean systems as controlled by the UN. It’s ridiculous.
So Malcolm and Lucy, where is the $444Million you stole to ‘fix’ the Great Barrier Reef when Blind Freddy knew it didn’t need fixing and even if it did, that money would do nothing? And it’s in fine shape today, only a few years later. So do we get any change? Where’s the money? And what about the $14million in the budget each year as interest on the stolen money? Or are you too busy lecturing Donald Trump on how to run a country?
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I guess it’s nothing to Alabanese’s spending on shares of $A1billion on a purely speculative California company for a Quantum Computer. If someone actually had $1Bn of their own money, they wouldn’t do it. So where’s the return? Where’s the business plan? When is parliament going to know what is going on and who actually benefits from this massive gift of cash?
It looks like Prime Ministers in Australia can do as they please with our money, with zero accountability. And aren’t they loving it.
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I guess it’s nothing to Albanese’s spending $A1billion cash on shares in on a purely speculative California company for a Quantum Computer, just when IBM is getting out and they invented it.
If someone actually had $1Bn, they wouldn’t do it. So where’s the return? Where’s the business plan? When is parliament going to know what is going on and who actually benefits from this massive gift of cash? Can we sell the shares and get the money back? Will we get a report to parliament on the ‘investment’?
It looks like Prime Ministers in Australia can do as they please with our money, with zero accountability. And aren’t they loving it.
Saving the planet, saving the Great Barrier Reef, saving jobs, saving aborigines. Only costing hundreds of billions of our dollars. A huge cost, but our leaders tell us it is necessary while they plan their retirement.
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