Measurements of the acoustic properties of the seagrass Posidonia oceanica

A one-dimensional resonator technique was used to test the acoustic response of fresh leaves of Posidonia oceanica collected from both Crete, Greece and Sicily, Italy. The sound speed was inferred from resonance frequencies measured between 1 and 8 kHz. This sound speed is also compared with ultrasonic time-of-flight measurements between 1 and 4 MHz. Measurements of intact leaves as well as a homogenous tissue “soup” were made to investigate tissue properties and the role of leaf structure in sound propagation. This work expands on similar measurements, published previously by the authors, made on three other seagrass species Thalassia testudinum, Halodule wrightii, and Syringodium filiforme.