Advanced Topic: Thoughts on Emerson Effect

[Dana Riddle]

The references I mentioned earlier:
Kinzie, R.A. and T. Hunter, 1987. Effect of light quality on photosynthesis of the reef coral Montipora verrucosa. Mar. Biol., 94:95-109.

Kinzie, R.A., P.L. Jokiel and R. York, 1984. Effects of light of altered spectral composition on coral zooxanthellae associations and on zooxanthellae in vitro. Mar. Biol., 78:239-248.

Wijgerde, T., et al., 2014. Red Light Represses the Photophysiology of the Scleractinian Coral Stylophora pistillata. PlosOne.

Riddle, D., 2003. Feature Article: Effects Of Narrow Bandwidth Light Sources On Coral Host And Zooxanthellae Pigments.

https://www.advancedaquarist.com/2003/11/aafeature

 

[Dana Riddle]

This and the fact that I have seen different growth pattern between same clone of hystrix there you have a lot of far red through MH compared with LED light (in the same water) was the reason why I start to try to figure out if these wavelengths have any impact for corals. I personally have a LED light without any wavelengths above 700 and get a growth pattern that I could not explain.

Sincerely Lasse

Yes, the real question I have is the effect (or non-effect) of far-red light. In absence of far-red, it is possible, in some cases, that a state transition ('spillover') occurs from PSII to PSI, that is, Photosystem II 'shares' energy with Photosystem I to keep electrons flowing, and not in a 'traffic jam' that could damage, or destroy, Photosystem II. But is this a universal effect, or limited to only a few, zooxanthella clades?

 

[jda]

Hypothetically speaking, if that "spillover" happens, does it do so in large enough quantities to really boost the light intake? It is no secret that 750 PAR from a 10K Metal Halide will cause coral to thrive after acclimation, but 750 PAR from 10k worth of LEDs will burn and kill the same coral. Is there some place where the spillover can help/happen, but still not as much as true relaxation with real R&FR waves (red and far red, I just made it up)? ...or is there a point where it happens to live, but not to thrive?

Any other theories why this happens in the real world? The only other one that I have, other than missing beneficial/symbiotic waves, is that there are peaks in the LED that are like cancer-waves. I don't know the science here, but this really happens and might be a problem worth solving.