@schabiazabi - I dont really agree that these points are not really verified. Maybe you are right but if so I think maybe you are asking for a degree of verification which is hard to attain.
Much of the really good stuff for instance is only available if you have access to the journals, I used to have this, alas no more. But still you can frequently find good papers if you look hard. For instance heres one I have open at the moment:
http://mediteran.aslo.net/lo/toc/vol_53/issue_2/0824.pdf
'Nitrogen and phosphorus co-limitation of bacterial productivity and growth in the oligotrophic subtropical North Atlantic'
This study took water from the ocean, and tested it for various parameters including bacterial counts and nutrients. They then spiked samples of the water with various combinations of nutrients and DOC, and retested it for many parameters including bacterial production and quantity. They also spiked samples with thymidine labelled with tritium, a radioactive isotope, to allow a sensitive test of biological activity (the reason for using a radioactive hydrogen atom instead of a normal hydrogen atom is so they can follow the incorporation of that particular atom into various biological pathways - its a method to directly label a set of atoms, and trace their use using something called liquid scintillation, so you can trace their use very specifically and accurately even down to extremely low quantities of a few molecules in several ml of liquid).
They accurately measure ammonia and phosphate to about 250 parts per trillion, and nitrate to about 1.5 parts per billion.
In this study they found that their samples were mostly N and P limited. You can read the whole paper for the whole story, its long and theres a lot more to it that what I just typed! But its a good example of what you can find if you look hard for the type of questions you are asking. I am not saying that this particular one will answer your questions, or that there is any study that will answer all your questions, but I think this one is worth reading as its quite along the lines you are discussing.
In the previous link I posted you can see that on the GBR, you can find levels around 1 ppm of DOC, but only about 3 ppb of inorganic N or P - frequently less than 1 ppb. So these waters are obviously not limited by DOC. I dont know about the reef you posted, Ill see if I can find any data for it - I never heard of it before, but I am no expert, just someone who likes reading scientific papers
As for why are corals thriving in a low DOC or low bacteria environment - I guess its unlikely to be as simple as corals having only one food. Seems to me a balance probably exists on successful reefs. My thinking is that corals can probably use nutrients from various sources. Some papers I read a few weeks ago showed that nutrient budgets in corals are varied and that suggests they might be flexible. I personally think that maybe one way to keep corals happy in a tank is a high bacteria, low nutrient system, but that there might be alternative water parameters with slightly higher inorganic nutes for instance.
Got to go but have a look at those links and tell me what you think of them, whether you feel they to address the questions any better. The GBR link interesting tables are around page 20 btw.
Much of the really good stuff for instance is only available if you have access to the journals, I used to have this, alas no more. But still you can frequently find good papers if you look hard. For instance heres one I have open at the moment:
http://mediteran.aslo.net/lo/toc/vol_53/issue_2/0824.pdf
'Nitrogen and phosphorus co-limitation of bacterial productivity and growth in the oligotrophic subtropical North Atlantic'
This study took water from the ocean, and tested it for various parameters including bacterial counts and nutrients. They then spiked samples of the water with various combinations of nutrients and DOC, and retested it for many parameters including bacterial production and quantity. They also spiked samples with thymidine labelled with tritium, a radioactive isotope, to allow a sensitive test of biological activity (the reason for using a radioactive hydrogen atom instead of a normal hydrogen atom is so they can follow the incorporation of that particular atom into various biological pathways - its a method to directly label a set of atoms, and trace their use using something called liquid scintillation, so you can trace their use very specifically and accurately even down to extremely low quantities of a few molecules in several ml of liquid).
They accurately measure ammonia and phosphate to about 250 parts per trillion, and nitrate to about 1.5 parts per billion.
In this study they found that their samples were mostly N and P limited. You can read the whole paper for the whole story, its long and theres a lot more to it that what I just typed! But its a good example of what you can find if you look hard for the type of questions you are asking. I am not saying that this particular one will answer your questions, or that there is any study that will answer all your questions, but I think this one is worth reading as its quite along the lines you are discussing.
In the previous link I posted you can see that on the GBR, you can find levels around 1 ppm of DOC, but only about 3 ppb of inorganic N or P - frequently less than 1 ppb. So these waters are obviously not limited by DOC. I dont know about the reef you posted, Ill see if I can find any data for it - I never heard of it before, but I am no expert, just someone who likes reading scientific papers
As for why are corals thriving in a low DOC or low bacteria environment - I guess its unlikely to be as simple as corals having only one food. Seems to me a balance probably exists on successful reefs. My thinking is that corals can probably use nutrients from various sources. Some papers I read a few weeks ago showed that nutrient budgets in corals are varied and that suggests they might be flexible. I personally think that maybe one way to keep corals happy in a tank is a high bacteria, low nutrient system, but that there might be alternative water parameters with slightly higher inorganic nutes for instance.
Got to go but have a look at those links and tell me what you think of them, whether you feel they to address the questions any better. The GBR link interesting tables are around page 20 btw.