20% of coral reefs dead

[archman]

http://www.cnn.com/2005/TECH/science/04/25/seychelles.coral.reut/index.html

This isn't new news by any means, but it's starting to get better press. Better do some more reef diving, they're going downhill fast!

 

[Boogie711]

And to no ones surprise, they're blaming global warming instead of destructive fishing practices or human interference.

Ho hum, ho hum. Until they start addressing genuine issues and stop throwing hysteria into the politically correct 'crisis du jour', we'll continue to see more of the same.

 

[archman]

Well, in all fairness to global warming, fewer and fewer scientists are disputing it. I pay close attention to "the current dope" amongst oceanographers and climatologists; half of my graduate committee are oceanographers. The rapid CO2 buildup in the upper water column is proving very difficult to explain away. There's also great swathes of coral nowhere near man that are tanking out. Linking their declines to direct anthropogenic effects is more problematic. My own field sites are quite remote, and they suck.

But causes aside, the reefs are dying. Most of my Bahamian teaching sites are in awful condition, and I wouldn't recommend them as diving destinations to anyone. The branching corals in the Caribbean are being proposed put on endangered species lists, as they're mostly all dead. I have to hunt far and wide to show living elkhorn corals to my students. Finding live staghorn is near impossible. I need to visit Saba before it goes to pot. :bubble_fi

 

[alcina]

I'd say come here where we have lots of happy healthy corals...but...

 

[MoonWrasse]

I don't know about global warming being the specific cause, however El Nino and thus changing ocean currents has caused a good percentage of that recent damage.

Not enough is really known about El Nino or La Nina to say with certainty man is responsible.

http://www.pmel.noaa.gov/tao/el-nino/faq.html

http://www.osdpd.noaa.gov/PSB/EPS/SST/retro.html

 

[archman]

Global warming is believed by many experts to be linked to heightened El Nino episodes. It'll also boost prevalence and severity of hurricanes, melt glaciers and ice caps, disrupt current regimes, alter water chemistry, dissolved oxygen content, blah blah blah... even fractions of a degree are significant within large water masses.

Hermatypic coral has very narrow thermal tolerances. Even short exposure to moderately elevated water temperatures can cause zooxanthellae to be purged, and if enough zooxanthellae leave a polyp, it's near impossible to recover.
That's what those nasty El Nino's did in the late '90's. They heated up a lot of water for a short period, and caused coral bleaching on an unprecedented scale. I've seen firsthand the effects of the 1998 El Nino myself on corals in Florida... seemed only the Palythoa enjoyed the hot water. I sure didn't. :flame:

Really not looking forward to the next El Nino episode.

 

[ScubaTexan]

And to no ones surprise, they're blaming global warming instead of destructive fishing practices or human interference.

My feeling is that there is plenty of blame to go all around...

 

[drbill]

And to no ones surprise, they're blaming global warming instead of destructive fishing practices or human interference.

Ho hum, ho hum. Until they start addressing genuine issues and stop throwing hysteria into the politically correct 'crisis du jour', we'll continue to see more of the same.

Destructive fishing practices and [direct] "human interference" cannot explain the decline in coral reef health across the globe, and as Archman points out in areas where direct human impacts are negligible.

There have to be larger scales forces at work here and global warming certainly seems a likely piece of the puzzle.

Dr. Bill

 

[archman]

Those flippin' Crown-of-Thorns aren't helping things in the Indo-Pacific. Of course, we think the starfish are going nuts due to people overharvesting their main predators, trumpet snails.

 

[Kim]

Yes, I've seen quite a few Crown of Thorns in Okinawa, but while they are bad it is not the cited reason for the most damage.

As far as what is killing the coral, around here at least it is too warm seawater temperatures. I suppose you can argue about why the sea is getting too warm.......but you can't argue the fact that it is.....and it kills coral.