Archives par mot-clé : Reefs

Australia

Happy Easter, Happy End of the 2023 Cyclone Season at the Great Barrier Reef

by J. Maroshasy, Apr 11, 2023 in WUWT

Year on year, however, contrary to human-caused global warming theory, neither the number nor intensity of cyclones has increased at the Great Barrier Reef. The available data shows that there has been a steady decline in both the number and intensity of cyclones since the 1970s.

This is probably why coral cover, as measured around the perimeter of coral reefs, is reported to be so high. The most recent Australian Institute of Marine Science survey reported coral cover to be the highest in 36 years. Cyclones can be incredibly damaging to corals, with fewer cyclones there will be more coral.

Contrary to expectations, this last 2022-23 season has also been quiet, with few cyclones. The exact number will hopefully be published at the Bureau’s cyclone page, that is here. But I doubt there will be a media release.

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See also: Bellies Full of Coral

Australia, better to know...?, Biodiversity

Chicken Little Propaganda Dressed Up As Science

by P.  Ridd, Nov 26, 2022 in InstitueofPublicAffairs

ORIGINALLY APPEARED IN THE AUSTRALIAN

The Bureau of Meteorology and the CSIRO have delivered their ­biennial dose of depression about the climate, but their report ignores a slew of positive environmental changes.

The Bureau of Meteorology and the CSIRO have delivered their ­biennial dose of depression about the climate in their latest State of the Climate report. The climate has warmed by 1.5C and there is barely a single benefit – it is all ­disaster.

It is often said, “if it is too good to be true, it probably is” and you are being conned. What about too bad to be true? Can a gently warming climate have no significant benefits at all? The only marginally encouraging part of the report is about northern Australia. There might have been a slight reduction in cyclone numbers, and there has been a bit more rain in the recent decades.

Apart from that, the report reads like the Book of Exodus – one disaster after another. Only the frogs and boils are missing.

But it is significant that the period when Egyptians were building pyramids, which was hotter than today’s climate, is often called the Holocene Climatic Optimum. The word “optimum” was an indication that scientists working in the era before climate alarmism could see some advantage of a warmer climate.

A sure sign that the report tries too hard to find disaster is when it discusses coral bleaching and the Great Barrier Reef. It stresses that there have been four bleaching events in the past six years, which it implies were devastating. But for some reason the report fails to mention that this year the reef recorded its highest amount of coral since records began in 1985.

This proves that all the hype about the coral loss from bleaching was greatly exaggerated. But the report writers were obviously ­untroubled by the contradictory evidence. They ignored it.

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unclassified

The Great Barrier Reef Is Doing Great; People Should Know

by P. Ridd, Aug 11, 2022 in CO2Coalition

Australia’s Great Barrier Reef (GBR) is, well, great. But the popular media won’t report this good news, so I will.

The GBR is made up of approximately 3,000 reefs covering an area nearly the size of California off Australia’s eastern coast. The condition of its coral is frequently referenced as an indicator of the reef’s health, regularly in the context of the supposed damage global warming is doing to the planet.

The reef now has more coral than any time since records began in 1986, according to  the Australian Institute of Marine Science (AIMS). There is roughly 20 percent more coral on the GBR than last year, which itself equaled a previous record year. All three major regions of the reef now have excellent coral cover and AIMS states that two regions are at record breaking high levels.

As of the latest 2022 survey of the GBR, coral covered 34 percent of the seabed, double the lowest coverage recorded in 2012. There are many types of ecosystem on reefs other than coral – 34% is a remarkably high number.

This coral health exists despite four supposedly massively destructive and unprecedented bleaching events striking parts of the reef since 2016 – all allegedly due to climate change and one as recently as this year. Coral reefs typically take five to 10 years to recover from major damage, so how can GBR be enjoying such good health this soon? Is it possible that reef-science institutions exaggerated the damage in the first place to advance the global warming narrative? Perhaps.

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Australia, biology+acidification

Latest Survey of ‘Coral Cover’ Fundamentally Unscientific

by J. Marohasy, Aug 11, 2022 in WUWT

According to the latest Australian Institute of Marine Science report, there is record coral cover at the Great Barrier Reef. Yet this is less than 30 percent at about half of the reefs surveyed.

The relatively low percentage cover is because only the reef perimeter is surveyed by AIMS, which is the equivalent of reporting on the population of Sydney after skirting around the outer suburbs.

Such a method (skirting around the outer suburbs) would give no indication of population trends in more densely populated inner-city areas. And so the latest AIMS report gives no indication of coral cover at reef crests, which for all we know given the methodology underpinning this latest survey, may have collapsed entirely across the Great Barrier Reef.

We cannot know.

Furthermore, despite advances in both underwater and aerial drone mapping, which could provide automated quantitative assessments by habitat with photographic and/or visual records, AIMS persists with a method that involves towing an observer who guestimates coral cover.

Their method is subjective and archaic. It is not scientific.

My early career was spent as a field biologist in Africa. If I had submitted the AIMS survey method as the intended survey method for any one of the many insect species that I monitored, my supervisors would have rejected it. Whether attempting to monitor changes in the population of an insect species, number of people in a city, or hard coral cover at the Great Barrier Reef, there are certain factors that need to be considered if the method is to be considered scientific and therefore reliable.

Key deficiencies in the current AIMS long-term monitoring program include:
1. Conclusions are drawn about overall coral cover at each reef without ever measuring coral cover at key habitats (E.g. at the reef crest).
2. Variability in coral cover is never quantified by habitat type (E.g. reef crest versus back lagoon).
3. The area surveyed at each reef (defined by AIMS as total ‘reef perimeter’ measured as sum of manta tows) incorporates results from different habitats, and as a consequence it is doubtful that the sample plan is adequate in terms of number of replications (manta tows) per treatment (habitat) at each reef perimeter.
4. Numerical values represent subjective guesses.
5. There is no photographic or video record enabling quantification of the accuracy of the guesses.

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Biodiversity, biology+acidification

CNN Pushes Coral Apocalypse As Great Barrier Reef Shows Record Growth

by H.S. Sterling, Aug 5, 2022 in ClimateChangeDispatch

A new report from the Australian Institute of Marine Science (AIMS) shows the Great Barrier Reef (GBR) set new records for extent this year.

Sadly, in a story titled “Parts of Great Barrier Reef record highest amount of coral in 36 years,” CNN tried to turn this good news contained in the headline into a climate cautionary tale. [bold, links added]

According to the AIMS annual report, the northern and central regions of the 2,300 km GBR ecosystem have the most coral since the surveys began 36 years ago.

As CNN notes, an AIMS survey of 87 sections of the GBR found that between August 2021 and May 2022, average hard coral cover in the upper region and central areas of the reef increased by around one-third.

AIMS CEO Dr. Paul Hardisty told CNN that the report shows the GBR can “recover from mass bleaching and outbreaks of crown-of-thorns starfish that feed on coral.”

One could be forgiven for missing this good news since CNN spent just a few paragraphs discussing the GBR’s expansion.

More than two-thirds of CNN’s story talked about the threat posed to the GBR from recent bleaching events purportedly driven by climate change.

CNN’s story largely ignored the fact that most of the GBR’s coral colonies impacted by bleaching had recovered, as the AIMS report documents.

In a press release from the Global Warming Policy Foundation (GWPF) commenting on the AIMS report its director, Benny Peiser, Ph.D., said, “This is just the latest example of empirical data making a mockery of the catastrophists. For how much longer do they think they can get away with it?”

The GWPF recently released a study discussing the positive health of coral reefs in general, by Peter Ridd, Ph.D., a long-time researcher on the GBR and coral reefs.

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biology+acidification

The Great Barrier Reef Is Strong, So Stop The Scare Campaign

by  P.  Ridd, Aug 5, 2022 in ClimateChangeDispatch

The latest data on the coral cover on the Great Barrier Reef, produced by the Australian Institute of Marine Science, should be a cause for celebration.

Church bells should be ringing and children given a day off from school. AIMS says two of the three main regions of the reef are at record-breaking high levels. [bold, links added]

The other region is at record-equaling levels (once uncertainty margins are taken into account).

AIMS, which has been releasing data on the reef every year since 1985, does not give the aggregate of coral cover for the entire reef; it stopped doing that in 2017.

So I have done it for AIMS, and the reef as a whole is at record high levels.

This result is proof that many scientific institutions have been misleading the public about the state of the reef.

They claimed we had four devastating and unprecedented bleaching events since 2016.

So much bleaching, death, and destruction has supposedly never happened before and is because of climate change – and now we have a record-high coral cover.

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climate and geology

The cement for coral reefs

by University of Erlangen-Nuremberg  Nov 2020, in ScienceDaily

Coral reefs are hotspots of biodiversity. As they can withstand heavy storms, they offer many species a safe home, and at the same time, they protect densely populated coastal regions as they level out storm-driven waves. However, how can these reefs that are made up of often very fragile coral be so stable? A team of researchers from Friedrich-Alexander Universität Erlangen-Nürnberg (FAU) and the University of Bayreuth have now discovered that a very specific type of ‘cement’ is responsible for this — by forming a hard calcareous skeleton, coralline red algae stabilise the reefs, and have been doing so for at least 150 million years.

The wide variety of life they support is immediately apparent on images of tropical coral reefs. Their three-dimensional scaffolding provides a habitat for a large number of species. However, the skeletons of the coral are often so fragile that they would not be able to withstand heavy storms by themselves. Even if scientists have long suspected that coralline red algae provide support to reefs with their calcareous skeletons, this is the first time that this link has been proven.

Coralline red algae have been supporting coral reefs for at least 150 million years

The researchers from FAU and the University of Bayreuth were able to prove this supporting function by analysing more than 700 fossilised reefs from 150 million years of the Earth’s history. ‘The coralline red algae form a calcareous skeleton and cement the coral reefs together,’ explains Dr. Sebastian Teichert from the Chair of Palaeoenvironmental Research at FAU. ‘However, several crises over the course of millions of years have limited their capacity to do so.’

Successful adaptive strategies against plant grazers

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biology+acidification

Reefs’ Neon Colors A Defense Against Coral Bleaching

by B. Bruno,  May 22, 2020 in ClimateChangeDispatch

Some coral reefs are adapting to warming ocean temperatures by making their own sunscreen in the form of bright neon colors — a strategy that invites coral animals to return to reefs and is seen as a critical adaptation to maintain healthy coral reefs around the world.

In a study published Thursday in the journal Current Biology, researchers at the University of Southampton detail a series of controlled laboratory experiments they conducted at their coral aquarium facility.

In the experiments, “colorful” coral bleaching events cause coral to produce a layer of vibrant sunscreen which encourages the coral animals vital to a mutually beneficial “symbiosis” relationship to return to coral habitats they abandon due to the effects of warming oceans.

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The colorful adaptation could prove vital for overcoming the fatal coral bleaching incidents that have threatened coral reefs worldwide.

But the colorful coral bleaching – rather than the white skeleton exposure of common coral bleaching events – is believed to take place due to mild ocean warming or disturbances in their nutrient environment, rather than extreme events.

Colorful bleaching occurred between this past March and April in some areas of the Great Barrier Reef, suggesting some patches of the world’s largest reef system may have better recovery prospects than others.

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biology+acidification, climate-debate

Climate At A Glance Factchecks–Coral Reefs

by P. Homewood, March 21, 2020 in NotaLotofPeopleKnowThat

Bullet Point Summary:

  • Coral thrive in warm water, not cold water.
  • Recent warming has allowed coral to expand their range poleward, while still thriving near the equator.
  • Coral has existed continuously for the past 40 million years, surviving temperatures and carbon dioxide levels significantly higher than what is occurring today.
  • The primary causes of coral bleaching include oxybenzone (a chemical found in sunscreen), sediment runoff from nearby coastal lands, and cold temperatures like those recorded in 2010 off the Florida coast.
  •  

Short Summary: Coral require warm water, not cold water, to live. Coral cannot live outside of tropical or subtropical waters. (See Figure 1.) As Earth continues to modestly warm, coral are extending their range toward the poles while still thriving at and near the equator. The primary reasons for bleaching events include sediment pollution from nearby coastal lands, chemicals found in sunscreen, and cold temperature events. Coral have existed continuously for the past 40 million years. Coral survived and thrived when temperatures were significantly warmer than they are today.

Figure 1: Coral Reef Locations

Continuer la lecture de Climate At A Glance Factchecks–Coral Reefs →

biology+acidification, climate-debate

STRANGE CORAL SPAWNING IMPROVING GREAT BARRIER REEF’S RESILIENCE

by University of Queensland, August 7, 2019 in GWPF

The discovery was made by University of Queensland and CSIRO researchers investigating whether corals that split their spawning over multiple months are more successful at spreading their offspring across different reefs.

Dr Karlo Hock, from UQ’s School of Biological Sciences, said coral mass spawning events are one of the most spectacular events in the oceans.

“They’re incredibly beautiful,” Dr Hock said.

“On Australia’s Great Barrier Reef, all coral colonies typically spawn only once per year, over several nights after the full moon, as the water warms up in late spring.”

Study co-author Dr Christopher Doropoulos from the CSIRO Oceans & Atmosphere said sometimes however, coral split their spawning over two successive months.

“This helps them synchronise their reproduction to the best environmental conditions and moon phases,” he said.

“While reproductive success during split spawning may be lower than usual because it can lead to reduced fertilisation, we found that the release of eggs in two separate smaller events gives the corals a second and improved chance of finding a new home reef.”

The research team brought together multi-disciplinary skills in modelling, coral biology, ecology, and oceanography, simulating the dispersal of coral larvae during these split spawning events, among the more than 3800 reefs that make up the Great Barrier Reef.

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biology+acidification

More Evidence for Rapid Coral Adaptation

by Jim Steele, April 2, 2019 in WUWT

Good news continues to accumulate regards corals’ ability to rapidly adjust to changing climates. The view of coral resilience has been dominated by the narrative of a few scientists. In the 1990s they advocated devastating consequences for coral reefs due to global warming, arguing coral cannot adapt quickly enough. Since the Little Ice Age ended, they believed rising ocean temperatures had brought coral closer to a “bleaching threshold”, a more or less fixed upper temperature limit above which corals cannot survive. Their model predicted the speed of recent global warming “spells catastrophe for tropical marine ecosystems everywhere”. Their assertions that “as much as 95% of the world’s coral may be in danger of being lost by mid-century” was guaranteed to capture headlines and instill public fear. However, a growing body of scientific research increasingly casts doubts on such alarming predictions. Unfortunately, that good news gets much less attention.

A recent peer-reviewed paper titled A Global Analysis of Coral Bleaching Over the Past Two Decades (Sully 2019) compared 20 years of ocean temperatures at which coral bleaching was initiated. From 1998 to 2006, the average sea surface temperature that initiated bleaching was 82.6 °F. But that temperature limit proves not to be “fixed” as earlier researchers incorrectly believed. From 2007 to 2017 the average temperature limit that initiated bleaching was higher, 83.7 °F. This indicates coral have been rapidly adapting to warmer regional climates much faster than once believed.

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better to know...?, biology+acidification

CORAL REEFS CAN TAKE THE HEAT, UNLIKE EXPERTS CRYING WOLF

by Peter Ridd, December 26, 2018 in GWPF

Scientists from James Cook University have just published a paper on the bleaching and death of corals on the Great Barrier Reef and were surprised that the death rate was less than they expected, because of the adaptability of corals to changing temperatures.

It appears as though they exaggerated their original claims and are quietly backtracking.

To misquote Oscar Wilde, to exaggerate once is a misfortune, to do it twice looks careless, but to do it repeatedly looks like unforgivable systemic unreliability by some of our major science organisations.

The very rapid adaptation of corals to high temperatures is a well-known phenomenon; besides, if you heat corals in a given year, they tend to be less susceptible in the future to overheating. This is why corals are one of the least likely species to be affected by climate change, irrespective of whether you believe the climate is changing by natural fluctuations or because of human influence.

Corals have a unique way of dealing with changing temperature, by changing the microscopic plants that live inside them. These microscopic plants, called zooxanthellae, give the coral energy from the sun through photosynthesis in exchange for a comfortable home inside the coral. When the water gets hot, these little plants effectively become poisonous to the coral and the coral throws them out, which turns the coral white — that is, it bleaches.

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biology+acidification, climate-debate, press and newspapers

‘Glimmer Of Hope’ For Great Barrier Reef As Study Shows Tolerance To Climate Change

by Nick Visser, December 10, 2018 in Huffpost

Last year’s oceanic heat wave wasn’t as destructive as one the year before, scientists said.

The Great Barrier Reef fared better during an oceanic heat wave last year than during sizzling weather a year earlier that caused hundreds of miles of corals to bleach, according to a study published Monday that suggests the massive structure may be growing more tolerant to climate change.

The report in the journal Nature Climate Change analyzed how corals along the Great Barrier fared in back-to-back mass bleaching events. The reef ― a UNESCO World Heritage Site and the largest living structure on the planet ― was cooked by overheated seawater in 2016 and again in 2017, with images of sickly white coral horrifying people around the globe.

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See also here

better to know...?, climate-debate

Can Universities Lawfully Bully Academics into Silence?

by Jennifer Marohasy, June 19, 2018

Dr Peter Ridd has taken James Cook University to court protesting his sacking for what he says is, primarily, speaking-out about the lack of quality assurance in Great Barrier Reef science.

Dr Ridd spoke out initially about there being no quality assurance of Great Barrier Reef science – science that is arguably misused to secure billions of dollars of tax-payer funding. When the University tried to stop Dr Ridd doing this, Dr Ridd spoke out against University management – making all the documentation public including on his new website.

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biology+acidification, climate-debate

Rise and fall of the Great Barrier Reef

by University of Sydney, May 28, 2018 in ScienceDaily

Over millennia, the reef has adapted to sudden changes in environment by migrating across the sea floor as the oceans rose and fell.

The study published today in Nature Geoscience, led by University of Sydney’s Associate Professor Jody Webster, is the first of its kind to reconstruct the evolution of the reef over the past 30 millennia in response to major, abrupt environmental change.

The 10-year, multinational effort has shown the reef is more resilient to major environmental changes such as sea-level rise and sea-temperature change than previously thought but also showed a high sensitivity to increased sediment input and poor water quality. (…)

biology+acidification, climate-debate

Bleaching of coral reefs reduced where daily temperature changes are large

by University of California – Irvine, April 26, 2018 in ScienceDaily

By taking a closer look, scientists find resilience in face of heat stress.

Coral reef bleaching is stark evidence of the damage being inflicted by global climate change on marine ecosystems, but a research team has found some cause for hope. While many corals are dying, others are showing resilience to increased sea surface temperatures, pointing to possible clues to the survival and recovery of these vitally important aquatic habitats (…)

See aslo here

better to know...?, pollution-contamination

Oceanic plastic trash conveys disease to coral reefs

by B. Friedlander, January 25, 2018 in CornellChronicle

“Plastics make ideal vessels for colonizing microscopic organisms that could trigger disease if they come into contact with corals,” Lamb said. “Plastic items – commonly made of polypropylene, such as bottle caps and toothbrushes – have been shown to become heavily inhabited by bacteria. This is associated with the globally devastating group of coral diseases known as white syndromes.”

When plastic debris meets coral, the authors say, the likelihood of disease increases from 4 to 89 percent – a 20-fold change. The scientists estimate that about 11.1 billion plastic items are entangled on reefs across the Asia-Pacific region, and that this will likely increase 40 percent over the next seven years.

better to know...?, biology+acidification

A ‘marine motorhome for microbes’: Oceanic plastic trash conveys disease to coral reefs

by Cornell University, January 25, 2018 in ScienceDaily

Plastics make ideal vessels for colonizing microscopic organisms that could trigger disease if they come into contact with corals,” Lamb said. “Plastic items — commonly made of polypropylene, such as bottle caps and toothbrushes — have been shown to become heavily inhabited by bacteria

climate-debate

Shoreline Change in Atoll Reef Islands

in Friends of Science, December 2017

This study gives irrefutable evidence on the persistence of atoll reef islands in French Polynesia over the last five decades, as 92% of the 111 islands studied exhibited either areal stability or expansion since the 1960s. Only 8% of the 111 islands showed contraction in area. Tropical cyclone waves contributed to island upward growth, which reached up to 1 m in places, through the transfer of sediments up onto the island surface.
climate and geology

Retrograde Accretion of a Caribbean Fringing Reef Controlled by Hurricanes and Sea-level Rise

by P. Blanchon et al., October 12, 2017 in Front.Earth.Sci

Predicting the impact of sea-level (SL) rise on coral reefs requires reliable models of reef accretion. Most assume that accretion results from vertical growth of coralgal framework, but recent studies show that reefs exposed to hurricanes consist of layers of coral gravel rather than in-place corals. New models are therefore needed to account for hurricane impact on reef accretion over geological timescales

biology+acidification

Prof Peter Ridd: the Great Barrier Reef recovers, our science institutions are failing us, science needs to be checked

by Alan Jones, interviews peter Ridd, July 28,  2017 in JoNova

Corals have a little thermometer built in them, when you take a core of them from many years ago we know what the temperature of the water was back when Captain Cook sailed up the coast, it was actually about the same temperature then. It was colder 100 years ago, but it has recovered from that. The temperatures on the reef are not even significantly warmer than average on a hundred year timescale.

Corals that bleach in one year will be less susceptible to bleaching in following years