Popular Science describes (a bit briefly) a real pearl of a concept, introducing the gentle, coast-restoring art of oyster-tecture:
Undoing our damage to oysters can help ease our impact on everything else. Each one can filter up to 50 gallons of water a day. Replenished beds could help restore the Chesapeake Bay and surrounding lands, a region known for rare birds, horseshoe crabs, and agricultural pollution.
When a wave breaks over an oyster colony, their clustered bodies slow the water, providing a natural seawall similar to coral. Bivalve-built reefs once protected vast tracts of the Atlantic coast, but overharvesting and pollution destroyed them. Hopefully we can rebuild these ancient buffers.