As you take in a beautiful view of the ocean, do you think of sound? There is a lot of it beneath the waves! Natural sounds are generated by wind, rain, waves, earthquakes as well as whales and dolphins. And did you know that fish sing as well? A wide variety of organisms can be identified, even shrimp, by the sounds they make. And the technology for detecting these sounds is becoming more and more effective.

At Monterey Bay National Marine Sanctuary, we are studying sound with some of the brightest acousticians in the world, including scientists at the Naval Postgraduate School, Monterey Bay Aquarium Research Institute, Hopkins Marine Station and many others. Hydrophones, listening for sounds, are anchored on the seafloor, drifting across the ocean’s surface, and a few can even detect the direction that a sound is coming from. The Research Institute has a cabled hydrophone that shares sounds coming directly from deep within Monterey Bay, 24/7. Listen for some live whale songs or recordings of other sounds in the research center listening room (mbari.org/project/soundscape-listening-room/).

Of course, for wildlife management, we are also interested in the sounds that humans make and their potential impacts. Sounds like engine noise from shipping lanes, seal bombs to deter mammals from getting caught in fishing nets and sounds like multibeam sonar — made to map what is in the water column and on the seafloor. Yes, we make sounds (active sonar) to study the ocean as well.

Andrew DeVogelaere, research coordinator at Monterey Bay National Marine Sanctuary, recounted, “Recent research findings using acoustic (sound) data include the surprisingly persistent presence of sperm whales in Monterey Bay National Marine Sanctuary; that blue and fin whales are often separated because they follow water masses of different temperature; and harbor porpoises communicate at such a high frequency (think pitch) that killer whales can’t hear them.” John Ryan, a biological oceanographer at Monterey Bay Aquarium Research Institute, added, “We’ve also documented the story of a cruise ship visiting Monterey Harbor, creating a variety of sounds, as part of a nationwide sound research program hosted by the Office of National Marine Sanctuaries (sanctsound.ioos.us).”

Many sea creatures are constantly using sound to communicate, navigate and locate prey.

Unfortunately, human-caused sound can mask or drown out these natural sounds. Changing propeller technology is one way to make ships quieter, and preliminary data indicates that sanctuary efforts to voluntarily slow shipping traffic is resulting in a quieter local ocean.

Eventually, we would like to integrate acoustic information in management decisions so we can better manage uses of the sanctuary. We’re not far away from being able to locate shifting “hot spots” of whale abundances, so crab fishery efforts and shipping lanes can be adjusted to avoid entanglements and collisions with these ocean giants, while still providing important services to the public.

Technology associated with the use and analysis of ocean acoustics, including machine learning to analyze massive data sets, will help inform wildlife managers in a way that is much less expensive than sending research ships at sea to make mammal observations, while also providing new kinds of information. Acoustic research will not completely replace all forms of ocean studies, but it will provide another way to more effectively learn about the ocean that we depend on. As these technologies and new analytical methods develop, you can envelope yourself in an exhibit featuring ocean sounds at our Sanctuary Exploration Center in Santa Cruz. Then, “make some noise” to protect the ocean for future generations.

Superintendent Lisa Wooninck and her staff at NOAA’s Monterey Bay National Marine Sanctuary conduct research, education and resource protection in one of most biodiverse marine protected areas in the world. Learn about new and exciting stories by the sanctuary within these articles. Wooninck can be reached at lisa.wooninck@noaa.gov. To learn more about the sanctuary, visit montereybay.noaa.gov.