Sand is not just great for building sand castles – it also serves as habitat for a myriad of benthic infauna (organisms that burrow)! Stellwagen Bank, an underwater plateau at the mouth of Massachusetts Bay, is made up of ancient bedrock covered by sand and gravel. The steep sides of the plateau cause deep-water currents to upwell (rise up), bringing nutrients and minerals from the bottom and feeding the ecosystem on the bank. Sand lance, a fish whose genus name Ammodytes means "sand burrower," are picky about the quality of the sand in which they make their home, preferring the type of sand found on Stellwagen Bank. The presence of sand lance attracts predators such as great shearwaters and humpback whales to the bank.