The abundance of bay grass in Chesapeake Bay has fluctuated greatly in the past decade. The following is a brief synopsis of some significant actions that have disturbed the growth of bay grasses.

• Eelgrass, the most widely distributed species in the bay, was nearly decimated by “wasting disease” in the early 1930’s.
   
  
• Despite significant increases in bay grass numbers by the 1940’s, introduction of exotic species such as water chestnut and Eurasian watermilfoil displaced many native bay grasses.
  
  
• Mute swans reproduced rapidly and began feeding on bay grasses after their introduction in 1962.
  
  
• Tropical Storm Agnes (1972) caused widespread damage to bay grass beds.
  
  
• Large scale declines in submerged aquatic vegetation in the late 60’s and early 70's due to increases in nutrients and sediments to the bay.
  
  
• Tracking of bay grass populations by scientists began in 1978.
  
  
• In 2001, bay grasses reached the highest numbers, an estimated 85,252 acres, since tracking began in 1978.
  
  
• Bay grass coverage was estimated to be approximately 64,709 acres in 2003.
   
• Baywide acreage increased 14% to 72,935 acres in 2004.

NOTE:  Scales on graphs are different

View Maryland’s Tributary Specific Bay grass coverage and Habitat Status (1984-2008)

View Baywide Yearly SAV Monitoring Project Reports at Virginia Institute of Marine Science
1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006