Tiny snapping shrimp amidst the oysters make a punctuated vibration that sounds to human ears like a snapped finger or a dropped pebble. Collectively they make it possible to hear the reef’s structure as a vertically layered crackling. And, we learned later upon analysis of field recordings, we were also hearing the oysters themselves. As each individual organism filters food from the water passing through its membranes, it expels excess material by rapidly closing its valves, emitting a low-pitched metabolic rumble.

The designer of this listening station, the ecoacoustic composer Matthew Burtner, had placed one microphone atop the reef and another inside an oyster shell on the beach. So we heard two worlds in our ears simultaneously: the living din of an underwater oyster city along with surface wind sibilating the dry carapace of a long-dead individual. Trying to still our feet from crunching the millions of shells on which we stood, we listened to the past and future and this coast.