The Chesapeake Bay 's underwater grasses suffered a 21-percent decline last year, according to a a report released this week by the Chesapeake Bay Program. That's roughly 15,000 acres of grasses, and it's close to lows last seen in 1986. Interestingly, the decline wasn't spread equally in all parts of the Bay.
According to the Virginian-Pilot's PilotOnline.com, while the Upper Bay overall sustained losses in the 30-percent range, the Susquehanna Flats remain robust. In the Middle Bay (Bay Bridge to the Potomac), underwater grasses declined 28-percent. And in the Southern Bay, they dropped by only 7-percent. An aerial survey conducted by the Virginia Institute of Marine Sciences shows new growth in the main stem of the James River.
What caused the decline? The combined effects of Hurricane Irene, Tropical Storm Lee, and an unusually hot summer in 2010. Water temperatures in 2010 were too hot for the underwater grasses, especially in the Lower Bay. Then the storms in the fall of 2011 resulted in greater amounts of sediment flowing into the Bay from rivers and creeks, particularly in the Middle and Upper Bay.
Poor water quality is tough on underwater grasses, which provide food and habitat for wildlife. The grasses also absorb nutrients, trap sediment, and slow shoreline erosion. They are an indicator of the Bay's health. The good news is these grasses will respond quickly when given favorable growing conditions.
For a cool time-lapsed map showing the growth (or decline, depending on the year) of Bay grasses, click here.
Thursday, April 18, 2013 - 22:47
The Chesapeake Bay 's underwater grasses suffered a 21-percent decline last year, according to a a report released this week by the Chesapeake Bay Program. That's roughly 15,000 acres of grasses, and it's close to lows last seen in 1986. Interestingly, the decline wasn't spread equally in all parts of the Bay.
According to the Virginian-Pilot's PilotOnline.com, while the Upper Bay overall sustained losses in the 30-percent range, the Susquehanna Flats remain robust. In the Middle Bay (Bay Bridge to the Potomac), underwater grasses declined 28-percent. And in the Southern Bay, they dropped by only 7-percent. An aerial survey conducted by the Virginia Institute of Marine Sciences shows new growth in the main stem of the James River.
What caused the decline? The combined effects of Hurricane Irene, Tropical Storm Lee, and an unusually hot summer in 2010. Water temperatures in 2010 were too hot for the underwater grasses, especially in the Lower Bay. Then the storms in the fall of 2011 resulted in greater amounts of sediment flowing into the Bay from rivers and creeks, particularly in the Middle and Upper Bay.
Poor water quality is tough on underwater grasses, which provide food and habitat for wildlife. The grasses also absorb nutrients, trap sediment, and slow shoreline erosion. They are an indicator of the Bay's health. The good news is these grasses will respond quickly when given favorable growing conditions.
For a cool time-lapsed map showing the growth (or decline, depending on the year) of Bay grasses, click here.