First hand accounts of the condition of the Great Barrier Reef?

[scubafanatic]

This is the second? major bleaching due to a strong El Nino since 1998. A lot of areas showed recovery after that one.

Which brings a question. How many times have major bleachings occurred in the last two centuries or more? Scuba divers have only been observing the reefs for about 60-70 years.

(this is not a GW denial comment,. Just a thought)

I remember seeing a science/documentary style story (TV , youtube, don't remember exactly where right now) where scientists studied that question via coral corings (taking sample drill cores from reefs to essentially travel back in time) and the results showed no evidence of coral bleaching events in the ancient past, the bleaching events were all recent, indicating they are human induced events, a consequence of fossil-fuel burning global warming.

What's worse, the major bleaching events are becoming more severe in magnitude as well as much more frequent, giving no possibility of recovery for corals between events, the 'between interval' is becoming shorter and shorter.

Even now, on any individual human timescale, the reef's practical recovery timescales are far beyond reasonable, if humans lived for hundreds/thousands of years we could afford to wait decades/centuries for a reef to recover, sadly that's not the case. I can just imagine a dive op responding to a disappointed diver guest, 'no worries, just come back next century!'

In addition to the 'warming', the excess CO2 is 'acidifying' the oceans, mucking up the water chemistry, reducing/eliminating the ability of corals (and anything living in shells, clams, oysters, etc.) to build their structures.

 

[diver0008]

the results showed no evidence of coral bleaching events in the ancient past, the bleaching events were all recent, indicating they are human induced events, a consequence of fossil-fuel burning global warming.

I am a skeptic, among other unpopular modern traits. There were no humans during the ice ages. Seriously major climatological events. The sun was the culprit. Not convinced that the sun is presently sitting comfortably, and leaving our climate alone.

What I do know is that there are considerably more human beings on this finite sphere than there were when I first arrived. Pollution is terrible for the environment, but I see it as a consequence not a cause.

 

[scubafanatic]

I am a skeptic, among other unpopular modern traits. There were no humans during the ice ages. Seriously major climatological events. The sun was the culprit. Not convinced that the sun is presently sitting comfortably, and leaving our climate alone.

What I do know is that there are considerably more human beings on this finite sphere than there were when I first arrived. Pollution is terrible for the environment, but I see it as a consequence not a cause.

Actually, earth IS heading towards it's next ice age (natural cycles due to earth's orbital variations around the sun)...BUT the ice age is being temporarily postponed due to the short term effects of humanity's short term 'burst' of CO2 emissions, which are temporarily offsetting the effects of what would normally happen due to the changing orbital cycles.

The sheer speed of humanity's impact on the planet is too fast for evolution to keep up, so we are careening towards the '6th mass extinction' which is unfolding RIGHT NOW! In another 100-200 years, we'll have finished burning off all the remaining fossil fuels, poisoned the atmosphere, and killed off the vast majority of life everywhere on earth, including perhaps humanity itself! Future generations of humans, should a few of us survive, will stare in utter disbelief at our short sightedness and denial of rational science!

The worst extinction event in earth's history, aka "The Great Dying', was the end-Permian extinction event about 250 million years ago, (when something like 95% of all species perished) was caused by an over heated atmosphere, global warming on steriods......humanity HAS been warned!

Take a look at the planet Venus to get a sampler of the end result of runaway global warming! Surface temps approaching 1000 degrees, surface pressures = to being 1/2 mile deep in our ocean, mountain tops coated with solidified molten metal 'snow'! Yes, it REALLY does rain molten metal (mixed with Steaming Hot Sulfuric Acid) on Venus!

Imagine being instantly crushed-to-death, while being sprayed with boiling sulfuric acid, coated with molten metal and vaporized...all simultaneously!

 

[CuzzA]

I remember seeing a science/documentary style story (TV , youtube, don't remember exactly where right now) where scientists studied that question via coral corings (taking sample drill cores from reefs to essentially travel back in time) and the results showed no evidence of coral bleaching events in the ancient past, the bleaching events were all recent, indicating they are human induced events, a consequence of fossil-fuel burning global warming.

I don't believe that for one second. No offense to you, but just from what I know about how reef building corals work and my own observations it would be impossible to ever figure that out.

Why?

Because corals naturally bleach and die as they grow. Take a tabling acropora for example. The beautiful pretty top of the coral you see while diving is growing and at the same time blocking light to the coral polyps and tissue below itself. Consequently EVERY coral and polyps bleaches and dies as it grows. The zooxanthellae within the corals tissue needs light to survive, without light, it dies and the coral expels it eventually killing the polyps and tissue in the shaded area. This is why they are called reef building corals. So being that bleaching is part of the process of a healthy reef building coral how could anyone ascertain that information from a core sample from a coral? They didn't find anything, because there's nothing to find.

 

[Wingy]

I did a school project in the 1970s on the death of the GBR due to bleaching.

I did a high school project in the 1980s on the death of the GBR due to COT starfish.

I did a project at uni in 1999 on the death of the reef due to Cane field fertiliser run off.

I'm not saying it's in perfect health - no marine ecosystem is anywhere on the planet at the moment. The OP referred to a writer posting an obituary - not sure of his/her credentials.

I hear in my travels there will be nothing left to see diving here in 10/20 years.

There is one woman who's opinion I do put stock in -

http://www.theaustralian.com.au/lif...t/news-story/a2c552677cbe0ff0f09f8ed282fbfd12

Val's opinion on the GBR death...this death, as opposed to the other ones mentioned above

 

[CuzzA]

A picture for reference to my earlier post. This is from one of my tanks. I grew this colony from 1/2". Notice how the coral is bleached underneath where it's shaded. Eventually all of those bleached polyps died and I cut the top half off and removed the dead portion.

Purple Stylophora.

* Everything you see in this picture was captive bred.

 

[diver0008]

In another 100-200 years, we'll have finished burning off all the remaining fossil fuels, poisoned the atmosphere, and killed off the vast majority of life everywhere on earth, including perhaps humanity itself!

Maybe.

Maybe not.

In any event, makes me wonder why no one has started building Atlantis.

 

[scubafanatic]

Maybe.

Maybe not.

In any event, makes me wonder why no one has started building Atlantis.

Atlantis HAS already been built...in our present era it is known as 'Miami', perhaps the 1st major city of our future 'Waterworld'. (or will it be New Orleans ?)

 

[CuzzA]

Atlantis HAS already been built...in our present era it is known as 'Miami', perhaps the 1st major city of our future 'Waterworld'.

And so think about this... Florida itself was once a giant reef at a time when the planet was much hotter (much less ice) and it died with the changes in the Earth's climate as the planet cooled.

 

[scubafanatic]

And so think about this... Florida itself was once a giant reef at a time when the planet was much hotter (much less ice) and it died with the changes in the Earth's climate as the planet cooled.

You may be forgetting it's the sheer SPEED of the HUMAN induced changes the reefs are facing, normal evolutionary processes just can't keep up, plus all the additional human induced pressures (nitrogen fertilizer/pesticide runoff, silt from harbor/cruise ship pier/overall development construction, massive overfishing, slaughter of apex predators (sharks), massive industrial accidents (ie Deepwater Horizon, etc.)...the list is endless!