Runoff Pollution Contributes to 21 Percent Drop in Bay Grasses in 2011

For the second year in a row, underwater grasses in the Chesapeake Bay declined in 2011 -– dropping by 21 percent from 2010, following a 7 percent decline the previous year, in part because of heavy rainfall and runoff pollution, according to the U.S. EPA Chesapeake Bay Program.

Hurricane Irene and Tropical Storm Lee turned the Bay into a muddy mess that looked like chocolate milk in satellite photos, and this muck smothered the grasses.

Aquatic vegetation is important to the Bay, because it filters silt out of the waterways and adds oxygen to water.  Grasses also serve as vital shelter for young blue crabs, striped bass, and other forms of life. The extent of grasses in the Chesapeake Bay, however, are now at their lowest levels since 2006.

The amount of grass is now “much more typical of what was observed prior to 1991 when grass acreages were at the lowest levels recorded” by aerial surveys, according to the Chesapeake Bay Program, which announced the results this morning. Contributing to the decline were hot weather and heavy rains in 2010 and 2011, which washed large amounts of sediment down the Susquehanna River and other waterways.

The decline in grasses, caused by stormwater runoff pollution, is a sign that the Chesapeake Bay states need to do more to install stormwater pollution control devices and build more runoff-control projects on farms to help meeet new Bay pollution limits (the Chesapeake Bay "Total Maximum Daily Load" or TMDL).  With too much murky runoff pollution, Bay grasses are smothered and deprived of light.

The long-term trend is that underwater grasses in the Bay remain at less than half the levels they were in the early to mid 20th century, before Hurricane Agnes in 1972 smothered many grass beds with muddy runoff.

Bay grasses have gradually expanded since that low point in the 1970s, and in 2010 were at 79,675 acres, or roughly double the roughly 35,000 acres of a quarter century ago, according to figures from EPA's Chesapeake Bay Program.  In 2011, however, the total extend fell to an estimated Bay-wide total of 63,074 acres, according to the Bay Program.

The Bay Program website gave this explanation for the decrease in grasses in 2011:

"According to Bob Orth, scientist with the Virginia Institute of Marine Science (VIMS) and coordinator of the annual bay grass survey:

1) Summer 2010 was unusually hot, causing severe eelgrass die offs in the lower Bay. These beds had already been measured for the 2010 acreage survey, so these eelgrass losses were not officially recorded until 2011.

2) In Spring 2011, heavy rains and resulting runoff created very muddy conditions in the upper Bay and its rivers during the bay grass growing season.

3) Last September, Hurricane Irene and Tropical Storm Lee brought even more rain and mud to the Bay’s waters."

By Tom Pelton

Chesapeake Bay Foundation

(Photo at top from Chesapeake Bay Program)

 

 

 

Comments

[Desiree (www.greenmomster.org)]

Since the blue crabs seemed to be doing well recently, what do scientists think these latest grass numbers will mean for the crabs (if anything)?

[Tom Pelton]

Great question, Desiree.

The decline in grasses will probably hurt crab populations. Junveile crabs need to hide in grasses so they aren't eaten by older crabs, as well as fish. Without this habitat, crabs are more vulnerable.

[Muhammad]

You know what's fun? Having lumps of spicy granules all over your hands from lumps of old bay that don't ralley add much flavor to the meat. The granules can't easily be wiped off, and when one goes to scratch their nose, a pleasant horrifying burning sensation envelops the face! Super! Oh, and the meat of Maryland crab! The meat! It's a whole 5 ounces of glory, just as much as one can find in ONE good King or Alaskan crab arm.When someone invites you to a Maryland crab bake they're @#$%ing with you. It's like saying that when your hand is bigger than your face, you have cancer and then bap-ing their hand into their face.Get yourself some Alaskan or King crab, melted butter and garlic instead.

[Hillary]

What about when the state poisoned the grasses in the l960's? Is there any information available about the name of the program, the cost, the people involved, what substances were used, what was the extent of the damage, how long did it take to kill the grasses etc.? What analyses have been done on the condition of the bottom of the creeks and rivers now as fas as how well they can sustain plant and fish life?

[replica watches]

I think this is a really interesting post. It is easy to get this article

[meizitang botanical slimming]

This post gives clear idea in favor of the new visitors of blogging, that really how to do blogging and site-building. meizitang botanical slimming http://bloggd.org/user/goodnice/blog/

[archeage gold]

Irrrm a sucker for providing most of these archeage gold http://www.mmogm.com/archeage/ using sweatpants plus slender a pair of jeans. I actually carry these individuals more or less every time it is actually distinctive outside. They are surely pretty extremely versatile in addition to a showstopper. I might suggest purchasing a measurements lower.