Deixem-me partilhar convosco excertos de um artigo que encontrei na net.

Podem consultar o texto integral aqui:

"Inside a Coral Lab"

Light is life - photosynthesis

"(...)Even today, the photosynthetic activity of zooxanthellae is measured. This is done to find out at what intensities the algae make optimal use of the available light. If too little light is provided, the algae produce less nutrients for the coral, limiting the growth of the latter. If too much is provided, the algae may damage themselves and their host, by the production of oxygen radicals. Next to this, energy may be wasted when light becomes less effective in stimulating coral growth. It is therefore very useful to measure photosynthesis in corals, so that light energy may be used optimally for coral aquaculture. (...)"

"(...)When regarding coral lighting, people usually think: the more, the better! For several years now, it is known that this is not the case. In reality, a light source such as a T5 or metal halide fixture is sufficient for good coral growth, which can be comparable to growth rates in the wild. It is true however that corals will increase in colouration when exposed to high irradiance levels, caused by changes in pigmentation of the coral tissue and zooxanthellae. Corals are able to increase their tissue pigmentation by production of a myriad of proteins, thereby regulating the amount of light which reaches their symbiotic algae, that reside in the coral gastroderm. Zooxanthellae are able to change their pigmentation as well, allowing them to control their photosynthetic efficiency. More coral pigments cause enhanced coral colouration, and more zooxanthellae pigments lead to browner, darker corals. This adaptation of the coral host and its algal symbionts is called photoacclimation or photoadaptation.(...)"

The importance of plankton

"(...)feeding corals with plankton is important as this is a source of essential nutrients. Although zooxanthellae are able to provide corals with ample energy, mainly in the form of glucose and glycerol, this is not sufficient for long-term growth. Every organism requires building blocks, for tissue growth and repair. These building blocks contain carbon, but also nitrogen and phosphorous. An athlete is very well able to exercise on a few tablets of Dextro Energy, but that person would need more to stay healthy. A daily dose of various nutrients is vital to long-term survival and health.(...)"

Go with the flow - water movement

"(...)Next to light and feeding, water movement also is of high importance to corals. Water flow is essential for food uptake, waste removal and gas exchange. For example, prey capture can be strongly influenced by the water flow rate around a coral. With the aforementioned flow cell, the water flow rate (measured in centimeters per second) can be manipulated very accurately, and the effect of flow rate on prey capture can be studied. Long-term effects of flow rate on coral growth can be determined as well, by exposing corals in experimental aquaria to various flow regimes for months at a time.(..)"

Só tive pena de não apresentarem resultados concretos no artigo. Fiquei muito curioso em conhecer os dados destas experiências (aparentemente muito rigorosas!), até porque concordo com tudo que é dito e gostava de ver evidências.

Um abraço,