Off the rocky coast of Maine, small, silver Atlantic menhaden are now so abundant that harbor seals, bluefin tuna, and bald eagles chase them into harbors, delighting fishermen. Along the sandy shores of Long Island and New Jersey, the return of massive schools are contributing to an increase in predators such as striped bass, dolphins, and humpback whales, which propel their giant bodies out of the water into the air, inspiring local artists and driving a sightseeing economy.