This was an incredibly fun high school engineering project. The beaches at Florida’s Guana Tolomato Matanzas National Estuarine Research Reserve (GTMNERR) had eroded due to boat traffic, and the spartina grass (endangered) was retreating up the shoreline. To mitigate this, we decided to build an oyster reef to shelter the beach, filter the water, and provide habitat for local wildlife. We drove around to local restaurants and picked up their used oyster shells and, after curing them in the sun, bagged them for placement on the reef. After two years of collection, bagging and building, we had made a half-mile long lattice of oyster shells perfect for colonization. We monitored the reef as it was being built, and young oysters in the water column quickly made their homes on our reef. It was a joy to see.