we seem to be running out of coral reefs...

[LeFlaneur]

OK - so don't do anything, and do it right now?


Hee hee.. clearly not. I guess then he would advocate more action and sooner.

And the alternative -- do nothing and hope that it will sort itself out?

 

[zboss]

With degradation occuring that rapidly, how could migration of reefs be tracked? Coral reefs take years (decades to centuries) to develop, like any other biome, so this is lightening speed stuff we're dealing with!


They meant "World Wildlife Fund" here, right?

Tom

One study used satellites to track growth and movement. Every coral gives off certain wavelengths of energy, which can be observed from space.

I work at the NSF and have direct access to the reports - trust me when I say that I know for a fact that they have conducted the research correctly.

 

[DennisS]

Is there a study corelating increased nitrogen and reef degradation on file anywhere?

 

[archman]

Is there a study corelating increased nitrogen and reef degradation on file anywhere?

Yeah, they're around. Here's a cutesy workshop page that synopses various reports on eutrophication (nutrient loading) in coral reef environs.
http://www.nacri.org/greylit/GastNutrPollWorkshop.html

Here's a quote from it

There are various well known examples of effects of eutrophication on coral reefs in the scientific literature. On Barbados reduced growth, reduced reproduction, reduction of successful settlement and changes in the coral composition have been recorded. On Jamaica the coral reef has been replaced by a macro-algae or seaweed reef helped strongly by heavy overfishing and a disease that wiped out the sea urchins. In Kaneohe Bay, Hawaii, heavy sewage discharge led to enormous amounts of macro-algae (up to 2.5 m high!) and an almost complete loss of corals. After the sewage discharge was diverted to deep water away from the island, the macro-algae disappeared and corals have come back to a reasonable extent. Although the precise causative mechanisms are often still unclear, there is no doubt that eutrophication has serious negative effects on the health of coral reefs.

The effects of increased nitrogen on corals is documented out the whazoo from the TRUE experts on this, the reef aquaria hobbyists. The literature in the field is more spotty, but is bulking up rapidly.

Hey zboss, could you cite the reports regarding remote sensing techniques for coral reefs? I'd like to know the blue light spectral range being used to isolate corals, the state of research on isolating specific wavelengths to taxa, interference variables, and overall accuracy of current techniques. A few years ago this work was still highly experimental and possessed quite an error rate.

 

[zboss]

Hey zboss, could you cite the reports regarding remote sensing techniques for coral reefs? I'd like to know the blue light spectral range being used to isolate corals, the state of research on isolating specific wavelengths to taxa, interference variables, and overall accuracy of current techniques. A few years ago this work was still highly experimental and possessed quite an error rate.

Because they represent on-going research by academics in fields which I am bound (and feel appropriately) to honor non-disclosure agreements on. However - what I can say is that everyone here should be very happy that the NSF exists because they provide grants to conduct research that otherwise would not be get done at all. This is especially true because so much of the science done under NSF grants have little, if any, immediate economic usefulness to business. In other words - people studying coral reef degredation and nitrogen aren't exactly going to get grants from fertilizer manufacturers.

Needless to say - the Bush admin just created an "ocean czar". I guess they figured out that the oceans have a lot of oil left

 

[Kim]

Here's a question for all you tropical divers that do repeat visits on the same sites.

Over time, have you observed any measurable differences in the community structure? By that, I mean abundance of critters, changes in types of critters, dead stuff, changes in water clarity/color, etc. Don't be shy!

I wasn't diving there over the same time period, but my mate - a Japanese istructor - has been. There are large stretches of the Okinawan coast that apparantly used to have really good coral - about 5 years ago. These days no-one dives there anymore as the coral is completely dead. This is supposed to be the case in many areas around the coast.
Further out - in the Keramas - I have been myself. What was the estimate for this area, 65% ? From what I have actually seen myself that would have to be closer to 75% or maybe higher. There are still patches left here and there - but you see an awful lot of the dead stuff too. It's really very sad, as it's easy to imagine what it must have once looked like. Think of some of the pictures of destroyed cities in the 2WW and you get some idea. Dead coral just looks gray and dirty, it also seems to be much more brittle and many small pieces lie around on the bottom - presumably victims of the typhoon storms - it's just too much to think that anyone could have done it with fins.

 

[archman]

Because they represent on-going research by academics in fields which I am bound (and feel appropriately) to honor non-disclosure agreements on.

What, are you kidding? You must not be a scientist; we don't talk like that. Heck, if its published, its public domain. Just drop me the name of some of the lead researchers... I can google for them easy enough, but that's time consuming.

Oh well, I'll do it myself. Bleah!
http://www.pcrf.org/ad.html

http://www.cofc.edu/~coral/Spectra.htm

http://www.cofc.edu/~coral/ReefRemoteSquared2.htm

http://geo.arc.nasa.gov/sge/coral-health/

After skimming through the various techniques and datasets, my impression is that there's still a long way to go here. Too few satellites, poor resolutions or sensor quality, and there are complicating environmental variables out the whazoo (i.e. water column effects, intraspecific variation in reflected pigments). The "zooxanthellae problem" alone will not be an easy one to overcome using spectral imaging. Pesky zooxanthellae... always causing trouble.

Whenever you see a widespread amount of research effort funneling into projects where the techniques aren't standardized, its an indicator to evaluate data very carefully; high error rates. Remote sensing of coral reefs is still a highly experimental field.

 

[zboss]

What, are you kidding? You must not be a scientist; we don't talk like that.

You guessed it! I am not a scientist. Regardless - you are correct in saying there is some error but you trust your GPS right? The research is "good-enough" to establish trends - especially when corellated to datasets used in other collection techniques.

 

[archman]

The research is "good-enough" to establish trends - especially when corellated to datasets used in other collection techniques.

Maybe. Integrating large-scale ecological datasets is critical to my research, and its a royal pain in the butt; anyone that says its easy is a neophyte or lying. Even when managed, you rarely get true correlative ability, even if the sampling protocols are quite similar. With remote sensing of coral reefs, the accuracy of the established spectral libraries for taxa is far from certain. Too many confounding variables, and intraspecific variation in reflected wavelengths. Without looking at the applications specifically, I'm assuming that the "trends" are limited to isolating "live coral" from "dead coral", and not much more detail beyond that.

That's still pretty good, for remote sensing anyway. And its all you need for the purposes of broad monitoring. I'm still dubious that spectral techniques will ever be able to circumvent the pigment variation problem within taxa. Oh well, nothing's ever easy in ecology.