High-frequency acoustic scattering from aquatic plants and seagrass leaf blades

Aquatic plants and seagrasses play a vital role in the littoral zone and shallow water ecosystems. They are important for carbon sequestration, habitat health, and seabed stabilization. Both aquatic plants and seagrasses are vascular plants with gas-filled internal channels, known as aerenchyma, with complex acoustic responses. Many previous field and laboratory experiments have shown that the acoustic response of vascular aquatic vegetation depends on tissue gas content, leaf blade structure, plant density, and photosynthetic activity, yet forward predictive models for acoustic propagation in aquatic plants and seagrass have not been realized. To help progress towards such a model, laboratory bistatic acoustic scattering measurements at 1 MHz were performed on aquarium raised Vallisneria spiralis. The measured results are compared to forward scattering measurements, at the same frequency, performed on naturally collected Mediterranean seagrasses Posidonia oceanica and Cymodocea nodosa. Microscopic images...