Cold-water corals form reefs, measuring from dozens to hundreds of meters in height in the deep sea, where they constitute true hotspots of biodiversity and biological activity.
Worms, sponges and bacteria
Mueller studied the ecological interaction between the most common species of coral, a species of worm living in the calcareous skeleton, a sponge and the microbes living on the coral.
In her doctoral research at the Royal Netherlands Institute for Sea Research and Utrecht University, she studied these interactions by providing possible food particles, such as algae with stable isotopes of carbon and nitrogen. Subsequently, she could trace the uptake and the metabolism of the various sources of food by these four main groups living in the coral reef.
The worm living in the calcareous reef turned out to be an important factor in stimulating the calcareous growth of the coral reef. It helps building a stronger skeleton. The sponge turned out to play an essential role in efficiently recycling nutrients within the reef community.
Scarce substances are not lost and the bacteria were responsible for providing inorganic nitrogen. These bacteria are mostly autotroph, which means they can produce cells from carbon dioxide, using chemical energy rather than sunlight as a source of energy.