Physical Environment

Zostera beds typically occur in physically-sheltered environments such as shallow inlets and lagoons. The plants stabilize the sediment within the beds and the canopy of leaves reduces current flow (Fonseca and Fisher, 1986). However, increased wave action and current flow, particularly during storms or floods, can remove sediments and cause damage to the eelgrass beds.

Storms and hurricanes have been observed to remove large areas of Z. marina (Wyer et al., 1977; Orth & Moore, 1983; den Hartog, 1987, Aio & Komatsu, 1996). After storms, large amounts of Zostera material can be deposited on the strandline of the shore. Fowler (1992) reported the degradation of Z. marina beds around the Isles of Scilly following winter storms in 1989 and 1990. Floods can also damage seagrass beds (Preen et al., 1995).

In extremely cold winters, the formation of ice amongst the sediments of eelgrass beds can lead to the erosion of surface sediments as well as uprooting of rhizomes and frost damage to foliage (Den Hartog, 1987). Critchley (1980) observed frost damage to Zostera on the Isle of Wight.

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