ABSTRACT

Corals play a huge role in our oceans by supporting the critical coral reefs and in Earth’s health. The way corals reproduce and grow has given insights in leading restoration programs. Communication is vital for all organisms to grow and exchange information. The coral specie Cyphastrea was tested for their hypothesized communication via ultrasonic sounds when undergoing the fusion method at different times of the day (morning, afternoon, nighttime). Both live and dead corals were tested with a digital oscilloscope in which the trigger level was raised above the highest peak of electrical noise to differentiate the ultrasounds emitted by the corals and the electrical noise. In total 25 ultrasound spikes were recorded for the live coral in contrast to none for the dead coral. Because precautions towards unwanted electrical voltages were taken and the dead coral displayed no spikes in the 30 trials, it reinsures that the spikes observed for the live coral were produced and emitted by the corals. Notably, 52% of all spikes occurred during the Nighttime intervals in comparison to 28% during Afternoon and 20% during Morning intervals. There seems not to be such a strong connection between the different growth rates of the individual corals and the number of spikes recorded for each. Still, this proposes that live coral can emit ultrasounds and more actively do so during the Nighttime than any other time of the day and so, if this communication can be understood and harnessed, a new foundation for restoration for corals worldwide is within reach.