Letter: Underwater grasses do absorb nutrients
This is in response to Mr. George B. De Marco’s letter about Celeste Dudley’s article on grasses (Readers Write, "Submerged grasses don’t filter bay waters," Jan. 20).
Underwater grasses do, in fact, absorb and use nutrients from the water. SAV beds are considered nitrogen "sinks" because they use and process nutrients in the water and sequester, or store nitrogen, in roots and sediments.
Underwater grasses also help trap and settle sediment out of the water, which improves water clarity, which helps establish more underwater grasses, which remove more nutrients and sediment, etc., etc.
Because of their capacity to absorb nutrients and settle sediments, scientists estimate that if the Bay’s underwater grasses were restored to their historical acreage, the grasses could remove nearly 45 percent of the nitrogen inputs to the upper Bay from watershed and atmospheric sources.
Underwater grasses release oxygen to the water and to sediments, which enhance and enable bottom-dwelling organisms to live and function.
Other sources to confirm all this? See EPA’s Chesapeake Bay Program website: http://www.chesapeakebay.net/baygrasses.aspx?menuitem=14621
See VIMS website: http://web.vims.edu/bio/sav/AboutSAV.html
See Chesapeake Bay Foundation website: http://www.cbf.org/Page.aspx?pid=523