CO2, pH og Koraller

" this study demonstrates that through rapid sea level fall, the 2015–2016 El Niño has impacted Indonesian shallow coral reefs well before high sea surface temperature could trigger any coral bleaching.

Sea level fall appears as a major mortality factor for Bunaken Island in North Sulawesi, and altimetry suggests similar impact throughout Indonesia."

" 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."

" Prof Ridd said it was difficult to see from aerial surveys whether coral at depths of 10m were bleached, while he had been unable to find out from the Prof Hughes-led researchers the depth of their underwater surveys."

Climate change triggered a global coral bleaching event in 2014, affecting a significant proportion of the world's coral reefs.
In 2016, the Great Barrier Reef Marine Park was affected by the worst coral bleaching on record.
As a direct result, an estimated 29 per cent of shallow-water coral was lost across the Marine Park — this equates to the loss of more than one in every four shallow water corals (to a depth of approximately 10 metres).
Coral bleaching did extend to deeper corals beyond depths divers typically survey to, but mortality cannot be systematically estimated. Shallow water corals are the most diverse and productive corals and most important to the tourism industry.
However, the impacts from the bleaching were highly variable across the 344,400 square kilometre area of the Great Barrier Reef Marine Park — an area bigger than Italy.
While over 75 per cent of this coral mortality occurred in the far northern region, the southern Great Barrier Reef had little or no mortality from bleaching in 2016.
The impacts of this bleaching event are currently ongoing .
A summary of regional findings is below and a Final Report - 2016 Coral Bleaching Event on the Great Barrier Reef is also available.

"However a before-and-after photograph presented in Hughes 2017 suggested the severe GBR bleaching they attributed to global warming primarily happened between February and late April. Their aerial surveys occurred between March 22 and April 17, 2016. And consistent with low tide bleaching, that is exactly the time frame that tide tables reveal reefs experienced two bouts of extreme low tides coinciding with the heat of the afternoon (March 7-11 & April 5-10). And such a combination of sun and low tide are known to be deadly."

Frank Lansner skrev:
Niels, du skriver:
"Du må hjertens gerne gætte på, at lav vandstand er mere end halvdelen af GBR problemet i 2016....
Uden dokumentation udover en fyret professor (pga code of conduct), så er der ikke mere kød på den påstand."

Det er så din vurdering, nu må vi se om det bliver undersøgt til bunds. Så længe det ikke er undersøgt så er det uvist i hvilken grad lav vandstand-scenarie spiller en rolle ved GBR i samme stil som Ambou et al 2017. fandt for naboen mod Nord, Indonesien.

"Så længe det ikke er undersøgt, så er det uvist i hvilken grad lav vandstand-scenarie spiller en rolle ved GBR - i samme stil som Ambou et al 2017. fandt for naboen mod Nord, Indonesien."

Frank Lansner skrev:
Frank skriver:

"Så længe det ikke er undersøgt, så er det uvist i hvilken grad lav vandstand-scenarie spiller en rolle ved GBR - i samme stil som Ambou et al 2017. fandt for naboen mod Nord, Indonesien."

Niels:
"Er helt uenig."

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Nothing to see here in the Great Barrier Reef.

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Terry Hughes der stenhårdt ignorerer lav vandstand har endegyldigt ret kan vi forstå.
Og Hughes konkluderer så at koraldød kun er et varme-fænomen. Slut prut.

Jawohl.

Og en af dem der har protesteret blev kort efter fyret.
Ergo har han ikke ret.
Kan vi forstå.

Jawohl.