Despite its small size, the lesser sandeel is probably the most important fish species in the North Sea. Lots of other marine animals eat this fish. You often find many marine predators where schools of lesser sandeel swim, such as large predator fish, seabirds and marine mammals. Do you see a large group of gulls and terns diving into the sea just off the shore? Then there's a good chance they've located a school of lesser sandeel. Keep watching the water since you might also spot seals, porpoises and dolphins. When sensing danger, the lesser sandeel burrows itself in very quickly, even when it is wet sand on the beach.