In many estuaries on the eastern seaboard of the U.S., oysters act as ecosystem engineers by accumulating into huge reefs rising several meters from the seabed;

• 在美国东岸，许多沿海河口都有牡蛎生长，牠们就像生态系的工程师，从海床层层堆叠出数尺高的大型礁岩。