Where have all the grasses gone?
Bay grasses have long been recognized as critical to the health and well-being of myriad Bay organisms. Not only does submerged aquatic vegetation (SAV) protect water quality and prevent erosion, it also provides food and shelter for fish, shellfish, invertebrates and waterfowl. For example, research has shown that the density of juvenile blue crabs is 30 times greater in SAV beds than in unvegetated areas of the Bay. However, today only about 10 percent of the historic levels of SAV beds remain. Although the primary cause of SAV decline has been attributed to elevated levels of nutrients and sedimentation, shoreline property owners and resource managers are also increasingly troubled by the mute swan populations impact on SAV. Mute swans feed solely on bay grasses, such as widgeon grass, sago pondweed, horned pondweed, Eurasian water milfoil and eelgrass. Feeding exclusively in shallow wetlands, mute swans also utilize large amounts of emergent vegetation, including cord grass, needle
