In order to understand why the oyster shells are valuable and worth recycling, you have to know a bit about oysters. I personally don’t eat a lot of seafood, so Leija graciously gave me a rundown. Oysters are bi-valved mollusks, or organisms with a two-part hinged shell that contains a soft-bodied invertebrate. To reproduce, they release eggs and sperm into the water, which meet and then begin the fertilization process, eventually becoming larvae.
Larvae swim and eat phytoplankton in the water column for about two weeks and then begin looking for a hard substrate to latch onto. Once they find it, they become spat (juvenile oysters), which dedicate all their energy into shell growth.
Problems arise when they don’t find anything suitable to grow on. That’s what has happened in Galveston Bay when Hurricane Ike blew through and deposited sediment on top of old historic reefs, suffocating them. The reefs have also been impacted by commercial dredging in the region.
“If there is not something hard like other oysters or oyster shell to attach to, they actually will descend into the sediment and suffocate and die,” Leija said. “You have to have something hard on that bottom of the bay for them to live on.”
Many people have found oysters attached to tires or old posts, Leija said, and they’ll pretty much grow on anything. However, she said that there are studies that show that oysters, which are reef-forming creatures, tend to want to stick together. Staying together also enhances their ability to reproduce and gives them a better chance of reproduction success. The discarded shells could offer a lifeline to the bay’s remaining oyster population.