ABSTRACT Globally, 85% of shellfish reefs have been lost during the past century. The severe loss of the eastern oyster Crassostrea virginica has encouraged different types of restoration efforts in the United States. In Mosquito Lagoon (ML), a shallow-water estuary on the east coast of central Florida, restoration focuses on providing additional substrate for larval recruitment via deployment of stabilized oyster shell. To assess the current number and area of natural, dead, and restored oyster reefs within ML, aerial photographs from 2009 were digitized using ArcGIS software. All reefs were screen digitized using a reef “signature” to estimate the surface area of each reef type. The maps from 2009 were then used as a guide to digitizing the historical aerial photographs (1943, 1951, 1967, 1971, 1984, 1995, and 2006). Oyster habitat within ML has decreased by almost 15 hectares between 1943 and 2009, which constitutes 24%of the 1943 lagoon-wide coverage. The impacts were greater in Canaveral National Sea...