Guest essay by Eric Worrall
The Guardian claims tour operators are refusing to take people to see coral bleaching on the Great Barrier Reef, for fear it will put tourists off from visiting. My question – if coral bleaching has killed the whole reef, why bother hiding it?
Great Barrier Reef: tourism operators urge Australian government to tackle climate change
Letter calls for rapid shift to renewable energy after natural wonder affected by worst coral bleaching event yet seen.
Tourism operators have broken their silence about the worst crisis ever faced by the Great Barrier Reef, with more than 170 businesses and individuals pleading with the Australian government to take urgent action to tackle climate change and ensure the reef survives.
Many tourism operators in Queensland have previously been quiet about concerns for the reef, fearful that speaking about the mass bleaching event would turn tourists away, lowering their incomes in the short term.
The Great Barrier Reef is in the midst of the worst bleaching event ever seen, with virtually the entire reef affected. Unusually warm water has killed as much as half the corals in the northern sections and scientists have found climate change will make the those conditions normal in fewer than 20 years.
A group has now spoken out, writing to several politicians, including the prime minister, the federal environment minister and local representatives, as well as taking out an advertisement in a Queensland paper.
“Many tourism operators, they don’t want people not to come to the reef, so they’ve been reluctant to speak out” said John Rumney, who has run diving and fishing tours on the Great Barrier Reef for the past four decades.
“They are worried it will have a negative impact on the short-term cash flow. But if we don’t take care of this issue we will have no reef in the future.”
Hangon, does that mean the reef is expected to recover from this episode of bleaching?
Australia’s largest oceanic reef system, Scott Reef, is relatively isolated, sitting out in the Indian Ocean some 250 km from the remote coastline of north Western Australia (WA). Prospects for the reef looked gloomy when in 1998 it suffered catastrophic mass bleaching, losing around 80% of its coral cover. The study shows that it took just 12 years to recover.
Spanning 15 years, data collected and analysed by the researchers shows how after the 1998 mass bleaching the few remaining corals provided low numbers of recruits (new corals) for Scott Reef. On that basis recovery was projected to take decades, yet within 12 years the cover and diversity of corals had recovered to levels similar to those seen pre-bleaching.
“The initial projections for Scott Reef were not optimistic,” says Dr James Gilmour from AIMS, the lead author on the publication, “because, unlike reefs on the Great Barrier Reef, there were few if any reefs nearby capable of supplying new recruits to replenish the lost corals at Scott Reef.
“However, the few small corals that did settle at Scott Reef had excellent rates of survival and growth, whereas on many nearshore reefs high levels of algae and sediment, and poor water quality will often suppress this recovery.
Read more: https://wattsupwiththat.com/2013/04/07/good-news-about-coral-reefs-they-recovered-from-warming/
What about the future? Assuming global warming occurs, what happens to reefs which are frequently subject to extreme temperatures?
We tend to associate coral reefs with tropical seas of around 28 degrees, where even slight warming can have devastating effects on corals. But in the Arabian/Persian Gulf, corals survive seawater temperatures of up to 36 degrees Celsius every summer, heat levels that would kill corals elsewhere.
In their study, the NOCS team worked closely with NYUAD researchers to select and characterise model corals from the Arabian/Persian Gulf, which will facilitate future molecular-scale investigations into why they can tolerate heat stress.
Read more: https://wattsupwiththat.com/2013/02/06/some-corals-do-well-in-warmer-waters-researchers-ask-how/
Perhaps there is a protective adaption which helps coral survive extreme temperatures?
That warning about poor water quality near coastlines, near human habitation is a concern – what could humans be doing, which might be stressing the corals of the Great Barrier Reef, causing them to become more vulnerable to warm water?
Swimmers’ Sunscreen Killing Off Coral
The sunscreen that you dutifully slather on before a swim on the beach may be protecting your body—but a new study finds that the chemicals are also killing coral reefs worldwide.
Four commonly found sunscreen ingredients can awaken dormant viruses in the symbiotic algae called zooxanthellae that live inside reef-building coral species.
The chemicals cause the viruses to replicate until their algae hosts explode, spilling viruses into the surrounding seawater, where they can infect neighboring coral communities.
Zooxanthellae provide coral with food energy through photosynthesis and contribute to the organisms’ vibrant color. Without them, the coral “bleaches” — turns white — and dies.
“The algae that live in the coral tissue and feed these animals explode or are just released by the tissue, thus leaving naked the skeleton of the coral,” said study leader Roberto Danovaro of the Polytechnic University of Marche in Italy.
The researchers estimate that 4,000 to 6,000 metric tons of sunscreen wash off swimmers annually in oceans worldwide, and that up to 10 percent of coral reefs are threatened by sunscreen-induced bleaching.
Read more: http://news.nationalgeographic.com/news/2008/01/080129-sunscreen-coral.html
Sun cream is a big deal in Australia. Schools demand parents apply suncream to children before attending. Sky high skin cancer rates, and decades of government campaigns, ensure a high level of awareness, and a relatively high rate of suncream application – especially when bathing under the blazing tropical sunlight of the Coral Sea. Newer suncreams, spray on nanoparticle creams, as opposed to the old oily white suspension, make suncream more convenient to apply, and less damaging to clothes. Even though applying suncream likely helps to kill the coral.
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This is probably an answer to my email to the Grauniad, in which I berrated them for not mentioning that the tour operators (and the tourists) were all saying that the reef was in great condition. Check out the website of the Quicksilver tour operator, working out of Cairns.
There are two separate threats to the reef, stress bIeaching and Crown of Thorns (CoT) starfish decimation.
Interestingly, this item from the Oz government marine department says that bleached corals are not dead. They are bleached but still alive, and take up to two years to die after a bleaching event. Which is why bleached corals can recover quickly, because they only need to recolonise with zooxanthellae algae and everything is back to normal.
Quote:
Acute or prolonged stressful environmental conditions cause a breakdown in this symbiotic relationship (with zooxanthellae algae), first revealing the fluorescent pigments and then leaving the white calcium carbonate skeleton visible through the coral tissue. Bleached corals can no longer gain energy from photosynthesis, and if bleaching persists for an extended period, corals will starve and die.
http://www.aims.gov.au/docs/research/climate-change/coral-bleaching/coral-bleaching.html
And in 2012, they were still saying that the greatest threat to the GBR was the CoT starfish, not stress bleaching. And it is thought that CoT blooms are enhanced by agricultural fertiliser runoff.
Quote:
In conclusion we can state unequivocally that CoTS remain the greatest threat to the coral of the GBR and thus also indirectly to coral reef fish, although obviously of lesser threat to seagrass, dugongs, and some other megafauna.
http://theconversation.com/great-barrier-reef-dying-beneath-its-crown-of-thorns-6383
When there is an imbalance in nature and the CoT is such (they only feed really on fast growing corals and not slow growing corals) then nature takes a while to adjust, with increasing numbers of CoT, this will lead to an increase in predators of CoT like the Giant Triton snail and the Stars and Stripes pufferfish.
Those populations will increase and address the imbalance eventually
We should mind our own business 😀
Right you are, Mark, …… just like the cycling “foxes n’ rabbits” population use to be in different areas in North America. A decrease in foxes = increase in rabbits. An increase in rabbits = increase in foxes. An increase in foxes = decrease in rabbits. A decrease in rabbits = decrease in foxes.
But many humans didn’t mind their business and they introduced a “wild card” that is detrimental to both the above “foxes n’ rabbits”. And that “wild card” is the house cat, ….. both the household “pets” that are permitted to freely roam the neighborhoods and the feral cats that were set free to reproduce and survive on their own in both the neighborhoods and countryside.
Those cats are deadly predators of both rabbits, songbirds and other gamebirds ….. and the cats only predator is the eastern US is the Coyote or Coy dog which might as well be “no predator”.
The ‘experts’ say that CoT larva has a better survival rate when fertilizer runoff helps increase plankton counts. While this sounds plausible, is it true? Do most CoT larva die under ‘normal’ plankton levels, then mostly survive when plankton levels are higher?
The other explanation seems more likely. When the number of CoT predators are reduced from over fishing etc., then CoT becomes a problem.
I got this from Stanford’s Microdocs:
Predators of Crown-of-thorns starfish larvae
•sponges
• bivalves
• sea squirts
• coral
Predators of juvenile Crown-of-thorns starfish
• Fireworms
• Harlequin shrimp
• some marine snails
Predators of adult Crown-of-thorns starfish
• Pufferfish
• Triggerfish
• Pacific Triton
Apparently Trigger fish and the Pacific Triton are often over fished.
“and the cats only predator is the eastern US is the Coyote or Coy dog which might as well be “no predator”
I would say (partly from personal experience) that the Bobcat is a considerably more efficient cat predator than the Coyote.
For what it’s worth.
I spent quite a few years sailing my yacht around New Guinea, the Solomons & other pacific islands. In quite a few areas at the time, little charting had been done. Much that had was based on much dodgy navigation by naval people during the Pacific war.
In places, even the coastline of islands was dotted, & there were many notations such as, this island reported 7 nautical miles southeast of its charted position, 1944.
In this environment I used my knowledge of coral to find passages through local barrier reefs. Rather than any product of human habitation, [not much of that in many areas in the islands], it is freshwater runoff from rivers that is toxic to coral, it can not survive in low salinity. Add the very large loads of silt that issues from rivers occasionally & you develop the usual pattern of a coral free band along the coastline, with a few entrances at river mouths.
The same thing occurs in mature lagoons. These can develop very low salinity within the enclosed area during more extreme rainfall years, which dramatically inhibits the coral growth with in a lagoon. Growth concentrates on the outer wall of the reef/islands that form the lagoon, in the full salinity of the open ocean.
It really is a pity that most researchers would rather play in a pond, with excess synthetic levels of CO2, than go outside, & look at the broad picture.
Floods of freshwater also lower the nutrient count too and starves them
If warmer water caused bleaching / death of coral, there would be no coral in the warmest seas such as the Indian Ocean and the furthest West part of the Pacific (Gulf of Thailand, Western part of the South China Sea, etc). Bbbbbbbbbut … there’s lots of coral in such places.
no no no, the environmentalists have collectivised corals under their banner, red banner. Lenin speaks for corals now.
Fake pictures of bleached coral have been shown on hundreds of websites. The original picture had nothing to do with bleaching, and has twice been altered to look bleached.
http://i64.tinypic.com/2rw8i0w.jpg
Every picture needs its origin checked.
The headlines read ‘97% of the Barrier Reef affected by coral bleaching’, in the usual alarmist way trying to paint a picture of the Barrier Reef on its last legs.
What a legitimate scientist could have written is that ‘coral bleaching could be detected on 97% of the ‘number#1’ sites examined. Of these sites, only ‘number#2’, or x%, showed moderate bleaching. Only ‘number#3′ sites, or y%, showed severe bleaching.’
But this would not be as effective in beating the drum.
Apparently there was no measurable amount of the chemicals in the water, but the effect is not dose dependent (just like homeopathy):
“Under normal situations on a coral reef, corals would not be subjected to these high concentrations because of rapid dilution,” van Woesik said.
But according to study author Danovaro, the effect is not dose dependent—so coral’s exposure to a very small dose of sunscreen is just as dangerous as a high exposure.
“there were few if any reefs nearby capable of supplying new recruits to replenish the lost corals at Scott Reef.”
Er… coral larvae are planktonic and drift with the ocean currents. Note that no tropical island in the Pacific or Indian ocean, no matter how isolated, is without corals.