Herring

Herring travel in vast schools through the cool sea, once so dense that the water flashed silver. They are an important food for many bigger animals. To keep in touch, herring even make faint sounds by releasing tiny bubbles of air.

For scientists

The Atlantic herring (Clupea harengus) forms some of the largest fish schools of all and is a key link in the food web of the North Atlantic. Herring communicate with short clicking sounds (Fast Repetitive Ticks) made by releasing tiny gas bubbles from the swim bladder. They rise into surface water to feed at night and sink into deeper, darker layers during the day.

Source: NOAA

Discover more