Chasing Corals

[Reefable]

Originally Posted by Twinfallz

Firstly, bleaching occurred in the most northern region of the GBR only.

What was the real cause of this bleaching event? Warmer water could have played a part. There was a record El Nino event after all, equal to the 1998 event, which was itself responsible for coral bleaching, directly due to the related rise in ocean surface temperature in that region, which is a measure of El Nino intensity. But, any related rise in ocean surface temperature is secondary to the most significant & critical factors responsible for coral bleaching. What are those?



As discussed by Ampou 2017 https://www.biogeosciences.net/14/817/2017/ Indonesian biologists had reported that a drop in sea level had bleached the upper 15 cm of the reefs before temperatures had reached NOAA’s Coral Reef Watch bleaching thresholds. 2015 altimetry data shows that sea level was at its lowest in the past 12 years, and this drop in sea level had likely been experienced throughout much of the Coral Triangle including the northern Great Barrier Reef (GBR), and then accelerated during the El Niño. They speculated sea level fall also contributed to the bleaching during the 1998 El Niño. Consistent with the effects of sea level fall, other researchers reported bleaching in the GBR was greatest near the surface then declined rapidly with depth.



Indeed the Great Barrier Reef had also experienced falling sea levels similar to those experienced by Indonesian reefs. Visitors to Lizard Island had reported more extreme low tides and more exposed reefs which is consistent with the extremely high mortality in the Lizard Island region during the 2016 El Niño. Of course reefs are often exposed to the air at low tide, but manage to survive if the exposure is short or during the night. However as seen in tide gauge data from Cairns just south of Lizard Island, since 2010 the average low tide had dropped by 10 to 15 cm. After previous decades of increasing sea level had permitted vertical coral growth and colonization of newly submerged coastline, that new growth was now being left high and dry during low tide. As a result shallow coral were increasingly vulnerable to deadly desiccation during more extreme sea level drops when warm waters slosh toward the Americas during an El Niño.



Furthermore, an El Niño in the Coral Triangle not only causes a sudden sea level fall, but it also generates a drier high-pressure system with clear skies, so that this region is exposed to more intense solar irradiance. In addition, El Niño conditions reduce regional winds that drive reef-flushing currents and produce greater wave washing that could minimize desiccation during extreme low tides. And as one would predict, these conditions were exactly what were observed during El Niño 2016 around Lizard Island and throughout the northern GBR.



Apology accepted!

Very interesting thanks for sharing


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[Megalonyx]

Interesting and surprising scientific rebuttal. I would like to point out that, in the movie, it was said that the southern portion of the Great Barrier Reef was spared from bleaching because of massive amounts of cold water dumped on it from a storm. In fact they had originally set up in the south expecting it to be bleached but had to move to capture the bleaching event.

Sea level dropped around 2010-2013 around Australia due to unusually heavy rains on the continent( Australia's geography resulted in the collection of water in the outback- please read more about this in the sources at the bottom). The only reason this has an effect on sea level was because of the unusually high rains Australia received during that time period-
Australia has been predicted and shown to be subject to heavier rains as an effect of climate change ( again sources below). That would seem to show that even if we assumed that bleaching in the northern Great Barrier Reef was caused by low sea levels that base culprit is still climate change.

https://www.scientificamerican.com/a...ea-level-drop/
https://www.npr.org/2013/08/20/21357...ea-levels-drop
http://www.dailymail.co.uk/sciencete...ea-levels.html
https://www.google.com/amp/s/amp.the...obal-sea-level
https://www.google.com/amp/s/phys.or...ia-climate.amp


Now, the coral beachings in Australia, as well as Hawaii, were caused by an El Niño event however this was an unusually long and strong one. It has been shown that El Niño events have occurred in some degree at least as far back as the beginning of the Holocene and generally occur every two to seven years. In this bleaching event the Great Barrier Reef lost 29% of its coral ( the northern parts losing almost 60%). This is certainly not a normal occurrence. El Niño events have been predicted to increase in frequency and duration as a result of climate change- in fact they already have. I don't know of anything specifically linking the El Niño event in question directly to climate change however I can leave you with plenty of sources that show that El Niño's are worsened by the effects of climate change.
https://e360.yale.edu/features/el_ni...may_get_wilder
https://www.nature.com/articles/nclimate2100
http://climatechange.cornell.edu/wha...ino-up-to-now/
https://www.google.com/amp/s/www.car...ming-study/amp
http://www.bbc.com/news/science-environment-24494398

Additionally, I think, correct me if I'm wrong since it has been several months since I watched the movie, all the bleached reefs they showed along with their bleaching time lapse were under water and not exposed to air at all. The Great Barrier Reef has an average depth of 35 meters, I simply don't see how a drop in 15 centimeters could have killed 30% of it by exposure, ( 60% in affected parts)

[rjjr1963]

The climate has never been static. Dramatic and rapid climate change events have happened over the eons. Volcanic eruptions, rapid global temperature changes and rapid changes in the environmental chemical composition. The changes and variables have given us a rich, abundant and diversified ecology. Man should mitigate his impact but these paid for alarmists are to be treated with skepticism and must develop verifiable theories which are falsifiable. This is the way of science.

[Scrubber_steve]

Originally Posted by Megalonyx

I would like to point out that, in the movie, it was said that the southern portion of the Great Barrier Reef was spared from bleaching because of massive amounts of cold water dumped on it from a storm. In fact they had originally set up in the south expecting it to be bleached but had to move to capture the bleaching event.

It’s beyond ridiculous to attempt to explain the absence of coral bleaching on the majority of the GBR by suggesting one storm could make any difference at all let alone have such a massive impact.
I’m surprised you haven’t cited man-made global warming as the cause of this massive amount of storm delivered cold water.

Originally Posted by Megalonyx

Sea level dropped around 2010-2013 around Australia due to unusually heavy rains on the continent. The only reason this has an effect on sea level was because of the unusually high rains Australia received during that time period-
Australia has been predicted and shown to be subject to heavier rains as an effect of climate change ( again sources below). That would seem to show that even if we assumed that bleaching in the northern Great Barrier Reef was caused by low sea levels that base culprit is still climate change.

The 2010-11 Queensland flooding event, which you incorrectly consider unusual as a result of man-made global warming, wasn’t unusual at all. These heavy flooding rains don’t occur yearly, but are a normal and regular occurrence in this area - for example - “Wivenhoe Dam, Brisbane’s main dam, was planned in the early 1970s as a flood mitigation and water storage dam. The 1974 Brisbane flood highlighted the need for flood protection for South East Queensland.” “Brisbane experienced major flooding in 1893, 1974 and 1996. The 2010 La Niña Modoki weather pattern, which brings wetter conditions to eastern Australia, was the strongest since 1973.”

The 2010-11 Brisbane & surrounding area flooding was made far worse by the fact that the dam was left near full capacity despite the forecasted cyclone & expected heavy rains. Rather than keeping the dam’s level generally lower to deal with heavy rain events, as was intended, or lowering the dam’s water level prior to the expected event by draining water into the Brisbane River, the rain waters flooded out of the dam, flooded the river and previously known flood prone zones that the dam was built to protect in the first place, and previously known flood prone zones the council had hence allowed to be built on.

As Fasullo notes – “a rare combination of three large-scale climate modes—La Niña, the Southern Annular Mode, and the Indian Ocean dipole” was responsible for the heavy rains, as well as cyclone activity. This is a natural occurrence, not man-made global warming.
Note: no need to post four newspaper links, all written in the same month & year, referring to the same exact theory by one person. One links sufficient.

As far as your link to future rainfall patterns in Australia is concerned, it’s merely a model projection based on arbitrary assumptions & input, has no value at all other than to the fellow who received grant money to produce it, & whose livelihood is reliant on the climate crises industry.

The 2010-11 La Nina rains had nothing to do with sea level fall during the period of the far northern GBR bleaching event. The 2010-11 event was responsible for an estimated fall of 7mm over a one-and-a-half-year time period. Further, as reported in August, 2013, on any of the four articles you posted, “atmospheric patterns have returned to normal, more rain is falling over the tropical oceans once more and the seas are rising again.”

Not only was sea level rising again from 2011, the estimated 7mm fall is insignificant compared to the 15cm fall (2016) as noted in Ampou 2017, and also by the average low tide fall of 10 to 15 cm as measured by tide gauges in Cairns.

Originally Posted by Megalonyx

Now, the coral beachings in Australia, as well as Hawaii, were caused by an El Niño event however this was an unusually long and strong one. It has been shown that El Niño events have occurred in some degree at least as far back as the beginning of the Holocene and generally occur every two to seven years. In this bleaching event the Great Barrier Reef lost 29% of its coral ( the northern parts losing almost 60%). This is certainly not a normal occurrence. El Niño events have been predicted to increase in frequency and duration as a result of climate change- in fact they already have. I don't know of anything specifically linking the El Niño event in question directly to climate change however I can leave you with plenty of sources that show that El Niño's are worsened by the effects of climate change.

Your five links, all concerning just two papers dealing with El Nino future projections, are again nothing but scary scenarios, both based on model projections that are based on arbitrary assumptions. They are not useful as they are not data, because they cannot be tested for accuracy.

The 2015-16 El Nino & the 1997-98 El Nino, were both officially classed as ‘very strong’ as measured by intensity. So were the 65-66, 72-73, and 82-83 events. Although it is true that the 2015-16 event lasted longer than the event back in 97-98, when both are measured for duration at the time they reached, and then fell below, an intensity classed as only ‘moderate’, the difference in duration between the two is insignificant.
When measured for duration at the intensity rating of ‘strong’ and above, and the intensity rating of ‘very strong’, again the difference is insignificant as is the overall intensity between the two events. Suggesting the 2015-16 event was “an unusually long and strong one” is not accurate if comparing it to the El Nino back in 97-98, 18 years earlier.

Your arguments are all based on blaming every natural event on man-made global warming. Now it’s responsible for making El Nino’s worse. But there is no proof of this, only arbitrary model projections. It’s a favourite but baseless claim endlessly repeated by climate alarmists.

Simply, create a concept & reality leaves the room. It goes; ‘the atmosphere is really really sensitive to increasing co2, & this will make the world really hot, and the oceans really hot, & this will kill all corals’.
It’s impossible to argue with a concept that suggests man-made global warming is responsible for everything. More heatwaves - more deadly cold snaps. More rain – less rain. More floods – more droughts. More severe snow storms – no more snow ever. More hurricanes – less hurricanes etc, etc. It’s a concept readily absorbed by even the most scientifically illiterate & naïve, who run with it.

What the data actually shows to be the most critical component in regards to the GBR and Indonesian bleaching event is significant sea level fall in that region exacerbated by El Nino.


As far as the Holocene is concerned sea levels were around 160 meters lower. No doubt ocean circulation patterns were significantly different. There was no GBR. The water was land ice. It melted when the ice age ended. Still is, naturally. The GBR started forming 8,000 years ago, during the Holocene Maximum, when average temperatures were estimated to be up 5 degrees Centigrade higher than present. Warmer ocean water too. How bout that.

Originally Posted by Megalonyx

Additionally, I think, correct me if I'm wrong since it has been several months since I watched the movie, all the bleached reefs they showed along with their bleaching time lapse were under water and not exposed to air at all. The Great Barrier Reef has an average depth of 35 meters, I simply don't see how a drop in 15 centimeters could have killed 30% of it by exposure, ( 60% in affected parts)

Well, they can decide what to, & what not to show in a movie, especially when its agenda driven propaganda. I haven’t watched the movie as its nothing but propaganda. I know this from looking into the people & organisations, & scientist involved in making the movie. It’s a follow on from ‘chasing Ice’, which I have no doubt is just more propaganda. They omit important facts, exaggerate others, & tell straight lies. But if he makes a living out of it, well, it’s a free world.

In any case, the Indonesian reefs were bleached by low sea level and not “temperature-induced bleaching” Ampou 2017.

On the GBR, shallow-water corals on inshore, mid-shelf & outer-shelf reefs were reported as the most affected. Consistent with the effects of sea level fall, researchers reported bleaching in the GBR was greatest near the surface then declined rapidly with depth.
No doubt that corals below the surface, even at the lowest tides were affected as well, as the El Nino generated clear skies causing more intense solar irradiance, reduced regional winds that drive reef-flushing currents that produce greater wave washing that would minimize the very warm pools of virtually stagnant water.

No doubt that some of the ‘movie’ corals were underwater when filmed, some even at low tide. But on what day? Low tide levels change from tide to tide, & day to day. For example; corals that were not exposed on the low tide on the afternoon of 5th March 2016 would have been during the periods between March 7-11 & April 5-10, for example.. http://www.bom.gov.au/ntc/IDO59001/I..._QLD_TP006.pdf

Coral mortality following extreme low tides and high solar radiation
https://link.springer.com/article/10...227-006-0573-0
On coral reefs, spring low tides are recurrent disturbances, but are rarely reported to cause mass mortality. However, in years when extremely low tides coincide with high noon irradiances, they have the potential to cause widespread damage. Here, we report on such an event on a fringing coral reef in the central Great Barrier Reef (Australia) in September 2005. Visual surveys of colony mortality and bleaching status of more than 13,000 corals at 14 reef sites indicated that most coral taxa at wave-protected sites were severely affected by the event. Between 40 and 75% of colonies in the major coral taxa (Acropora, Porites, Faviidae, Mussidae and Pocilloporidae) were either bleached or suffered partial mortality. In contrast, corals at wave-exposed sites were largely unaffected (<1% of the corals were bleached), as periodic washing by waves prevented desiccation. Surveys along a 1–9 m depth gradient indicated that high coral mortality was confined to the tidal zone. However, 20–30% of faviid colonies were bleached throughout the depth range, suggesting that the increase in benthic irradiances during extreme low tides caused light stress in deeper water. Analyses of an 8-year dataset of tidal records for the area indicated that the combination of extended periods of aerial exposure and high irradiances occurs during May–September in most years, but that the event in September 2005 was the most severe. We argue that extreme low-tide, high-irradiance events are important structuring forces of intertidal coral reef communities, and can be as damaging as thermal stress events. Importantly, they occur at a time of year when risks from thermal stress, cyclones and monsoon-associated river run-off are minimal.
End.

Coral Mortality and Resilience

There are 4 widespread misconceptions about bleaching propagated by tabloid media hyping climate doom and researchers like Hoegh-Guldberg. To clarify:

1 Bleaching is not always driven by warming temperatures

2 Bleaching is not responsible for most coral mortality.

3 Coral can rapidly respond to disturbances and replace lost cover within a decade or less.

4 Bleaching, whether or not it results in coral mortality, is part of a natural selection process from which better-adapted populations emerge.

Severe 2010 Cold-Water Event Caused Unprecedented Mortality to Corals of the Florida Reef Tract and Reversed Previous Survivorship Patterns
http://journals.plos.org/plosone/art...l.pone.0023047
In January 2010, coral reefs of Florida, United States, were impacted by an extreme cold-water anomaly that exposed corals to temperatures well below their reported thresholds (16°C), causing rapid coral mortality unprecedented in spatial extent and severity.

The impacts recorded were catastrophic and exceeded those of any previous disturbances in the region. The mean percent coral mortality recorded for all species and subregions was 11.5% in the 2010 winter, compared to 0.5% recorded in the previous five summers, including years like 2005 where warm-water bleaching was prevalent.

[jestronix]

Most people if they get a severe illness like cancer will go and see a doctor and follow all avenues of scientific research based treatments , do they argue there's no proof and walk off ? Do they argue with the doctor and say these drug treatments are just scaremongering ? How interesting it is that we pick and choose when scientific research is credible usually when it only effects us right ? In most cases I suspect it's all for ego and the need to argue and justify a strong need to be different!

If you didn't shed a tear in this doco or feel some emotional response you may need to ease up on the Xanax, err which is also based on scientific research !

If you don't believe in scientific research based methods and they that are falsified by a group of extreme leftists, it may be time to drain your tank and put some plastic corals in and a few rubber fish! Oh and burn those test kits you have, surely they are the work of the devil ?

In all seriousness though, believer or non believer it's sad to see all those bleached corals and the countless losses of life underneath.