Sensitivity to Natural Events

Like all marine biotopes, eelgrass beds are subject to natural change. Zostera beds are known to be spatially dynamic, with advancing and receding leading edges, causing changes in coverage. Naturally-occurring changes can take place at a range of scales, with effects ranging from small alterations to Zostera coverage or density, to destruction of entire beds over large geographic areas. This chapter considers the main naturally-occurring processes known to affect eelgrass beds. Changes induced by human activities are considered in Chapter V.

Naturally-occurring agents of change can be conveniently divided into those relating to the physical and biotic environments of Zostera beds.

Physical Environment

Biotic Environment