During the rising spring tides from February to June, the usually quiet Colorado River Delta is overcome by a low-pitched buzz. The drone pervades the estuary, and hundreds of fishermen, hunkered down in small boats known as pangas, follow the sound. As the fishermen make their approach, the buzz turns to a roar.
In the water below, more than a million Gulf corvinas churn the water in a spawning frenzy. But the noise is more than just the sound of fish thrashing—it’s the mating chorus of hundreds of thousands of males.
These love calls are thought to bring the fish together. They also draw the attention of fishermen and their nets. But in a new study, led by Scripps Institution of Oceanography marine biology doctoral candidate Timothy Rowell, the call of the fish can play another role: as data for a census.
Photo: Régis Lachaume/Wikimedia Commons (CC0)