News Elevated Phosphate reduces coral bleaching

Interesting but I don't think this can used as a blanket endorsement not to worry about phosphate. I think the primary conclusion is that at higher temperatures corals reduce nitrogen uptake and require greater phosphate. Now whether this applies to all stress events or just temperature I don't think can be concluded. There's also nothing addressing long term whether there is a Phosphate threshold that stunts coral growth/color if it is present long term. So lets say that under normal conditions corals are up-taking Nitrogen (DIN) as opposed to Phosphate (DIP). During normal conditions they feel free to grow. If Phosphate is high then can this act in some way to trigger the coral to react as if it is in a stress event and start uptaking Phosphate? If Phosphate is vital to protect corals in stress events, it would make sense that corals focus on preservation not growth during such an event. A lot more would need to be done to determine phosphates interaction with coral, such as whether above (or even below) normal phosphate levels can cause the coral to enter the preservation stress cycle and stunt growth/color.

And I'll add. Maybe high phosphates actually encourage growth and color. Maybe it is natural for certain stressed coral to actually explode in growth using phosphate as a fuel under some survival mechanism that if there's more polyps there's more odds that the colony survives.

 

And an additional thought. When corals die and zooxanthellae I imagine phosphates are released. If levels then become higher in the water could this then be a trigger for a defense mechanism for the surviving corals to begin uptake of Phosphate to protect them in some way while at the same time taking advantage of a new nutrient source.

 

I've been thinking about this, and while the theory makes sense I think hobbyists will have a problem implementing this. If you make a mistake and your phosphates are high, I think most hobbyists will end up with an algae problem that will be hard to control.