Historical oyster reef connections to Chesapeake Bay – a framework for consideration

Lieutenant Francis Winslowʹs 1878 oyster survey data of the lower Chesapeake Bay provided the spatial context for considering connectivities of Crassostrea virginica to estuarine function and food web dynamics. Winslow measured the area, water depths, and in some cases bed thickness for 70 distinct oyster beds in the 368 km2 Tangier-Pocomoke complex, and 12 beds in 35 km2 of the James River oyster reef habitat. Individual beds showed great size variations, yet most were <2 km2. Beds occupied variable water depths, but most occurred in 1–4 m depths near shore and 2–12 m depths along channels. Varied bed-top topography and elevation changes created complex structures and hydrologic corridors between shores and tributaries. This historical spatial data provide a framework for considering oyster beds in the context of modern research to suggest they formed resource patches in the seascape at the estuarine scale. It is suggested that beds at different locations are connected by hydrologic corridors, and they facilitate dispersion, migration, and recruitment. Also, oyster-reef habitat added topographic roughness and spatial heterogeneity that increase resource-use options important to an active and diverse estuarine community moving between shore and tributary systems, and between Bay waters and watershed systems