The Guana River Estuary in northeast Florida is impaired due to excess nutrients, which can fuel eutrophic algal blooms. Oysters naturally filter estuaries, but modern data is limited. This project aims to reconstruct a longer history of oysters using the preserved shells within living reefs. The goal is to quantify how much oysters were capable of filtering in the past compared with today, providing a long-term perspective to inform what oyster restoration decisions are feasible.