We often think of the deep ocean as a dark and silent place, and while there is no light on the bottom of the Monterey Canyon, it is far from silent. And if you're curious what that sounds like, you can tune in. The Monterey Bay Aquatic Research Institute (MBARI) has an array of hydrophones deployed in the Monterey Bay that streams underwater sound continuously.
Underwater sound comes from a broad range of sources, including maritime shipping, biological activity, and offshore construction. For instance, whales can use low frequency sound (roughly 10 Hz to 8 kHz) to communicate over remarkable distances. Near the surface of the ocean, underwater noise is emitted from surface processes such as wind, rain, and breaking waves. Currently, insights into underwater sound are mostly provided by free-floating hydrophones, augmented with some seafloor-mounted systems. Changes in commercial marine traffic are being monitored by NOAA to observe and potentially mitigate harmful effects of shipping noise. The study of acoustics is fascinating and the origin of some sounds recorded by hydrophones around the world remain a riddle.
Our team developed Strider, a modular and low-cost autonomous surface vehicle, to provide autonomous positioning, real-time (and broad-band) communication, and solar power for oceanographic instruments. A fleet of Strider ASVs equipped with hydrophones can provide unprecedented resolution and long-dwell detection capability of underwater sound and activity. The Strider internet remote controls and live streaming options, enable real-time detection and analysis of underwater sound, to provide immediate insights.
A special thanks to Frank and Kaus from Integral Consulting, Inc. for the invitation to deploy with them and to Capt. Jim for hosting us on the R/V Shana Rae.