The Dieout of Zostera marina on the seaside of the Eastern Shore of Virginia

Jennifer Taylor

The goal of this study is to provide some insight into the dieout of the seagrass Zostera marina, commonly called eelgrass, during the late 1920's and early 1930's along the seaside waters of the Eastern Shore of Virginia. According to the studies done on the dieout, the cause of the extinction was a phenomenon known as the "wasting disease". Unfortunately, the "wasting disease" is considered by most to be a "disease" composed of a variety of factors rather than limited to only one or two. Some scientists feel that the dieout was caused by factors such as salinity extremes, waterfowl grazing, and storms while others feel that it was caused by human stresses such as harmful chemicals, increasing turbidity, and eutrophication of the water column. The current study is based mostly on eyewitness accounts of the eelgrass dieout from the Shoremen who experienced it first-hand.

The overall consensus among the persons interviewed provided some interesting information that can help in understanding the "wasting disease" and its components. According to the Shoremen, the eelgrass dieout began around 1927 and ended with the devastating storm of 1933 when the seagrass was completely wiped out. The scallops also died with the eelgrass. Waterfowl decreased dramatically since they derived their main nourishment from the beds of grass. All of the Shoremen describe the incredible clarity of the water before the dieout. The beds of eelgrass would impede the flow of the current which allowed the grass to pick up particles necessary to its survival. After the eelgrass began to die, the current became more rapid. Many of the marshes were changed according to the Shoremen. Most of those questioned pointed out exact locations of once high marshes that presently are very low marshes or just water because the marsh has sunk. Most of the men describe how the marshes change with every storm. Some even observed the presence of sand and mud layers which had washed over the marshes during the storm of 1933. Although eelgrass died along most of the east coast during the late 1920's and early 1930's, almost all of it had recovered and reappeared except for the grass that was once in the seaside waters along the Virginia coast.

This study is an ongoing effort in trying to comprehend the extinction of Zostera marina in the seaside waters of the Eastern Shore of Virginia. With information gained from Shore natives who observed the changes in the late 1920's and early 1930's, it may be possibly to link certain factors to the dieout of this seagrass.