Bay dead zone to be 'bad as usual'
By PAMELA WOOD, Staff Writer
The
Chesapeake Bay should have a large swath of water devoid of oxygen again
this summer, threatening the survival of fish, crabs and oysters. About
1.39 cubic kilometers of the bay - a long line stretching from northern
Anne Arundel County to the tip of St. Mary's County - is expected to
have so little oxygen that almost nothing can survive, according to a
forecast issued this morning.
That's considered to be "average" when compared with the past
22 years.
Or, as Dr. William Dennison of the University of Maryland put
it: "Bad as usual."
This dead zone encompasses water that has 0.2 mg/liter or
less of oxygen in the water, a state called "anoxia." Most fish prefer
levels of 5 mg, and crabs need 3 mg.
A larger zone of low-oxygen water - 2 mg or less, or "hypoxia" -
also will hit the bay this summer. The forecast for that area will
be available later this month.
And this is just the main stem of the bay - not the rivers
and creeks. There's increasing evidence that the rivers and creeks
also experience a severe lack of oxygen.
When there's no oxygen in the water, there's a constant
stress on marine life as it tries to survive.
It can lead to crab jubilees, when crabs scurry toward
land in an effort to find oxygen-rich water. It also can
lead to fish kills, such as one last week in Baltimore's
Inner Harbor that had thousands of dead fish floating in
the water at a prime tourist attraction.
Oysters and clams, sitting on the bay floor with
no way to move, simply die.
Frustrated at yet another sign that the bay is
in trouble, the nonprofit Chesapeake Bay Foundation released
a blistering statement from Roy Hoagland, its vice pres-ent
for environmental protection.
"It is a real tragedy when a huge segment of
the Chesapeake Bay is expected to be devoid of oxygen,
and the government calls it moderate," Mr. Hoagland
said.
The foundation used the forecast's release
as a platform to talk about the need for more money
to help the region's farmers implement bay-friendly
practices. The federal Farm Bill is up for reauthorization
before Congress, and the foundation is pushing a
measure that would direct more of the government's
agriculture money to the bay region.
"That the bay is in critical condition is
no surprise; the surprise is that that condition
is acceptable," Mr. Hoagland continued. "It is
outrageous that our elected leaders have not broadly
implemented proven programs that will reduce pollution
and restore our rivers, streams and the Chesapeake
Bay."
Officials at the Chesapeake Bay Program
- the federal-state partnership that oversees
the bay cleanup and released the forecast - acknowledged
that the bay still has a long way to go.
"The forecast reminds us that we must
continue to aggressively pursue restoration
efforts throughout the entire Chesapeake Bay
watershed," Director Jeffrey Lape said in a
statement.
But Mr. Lape said it's not up to the
government alone to rescue the bay. He called
on the 16 million residents of the bay watershed
to lend "active support" to the cause.
In 2000, state and federal leaders
set ambitious goals for cleaning up the
bay by 2010 and getting it off the nation's "dirty
waters" list. But 2010 is approaching,
and few of the goals have been met. Many
of the goals will be impossible to reach
by 2010, such as restoring thousands of
acres of wetlands and grass beds, or increasing
the populations of oysters and fish.
The forecast was developed by
scientists from the University of Maryland,
the Maryland Department of Natural Resources,
the U.S. Geological Survey and other
agencies. They look at factors such as
rainfall, river flow, temperature and
other things that vary from year to year
and can affect the bay's health.
For example, heavy spring rains
flush nutrients into the water that
cause algae blooms, which eventually
die and suck oxygen from the water.
A dry year sometimes means fewer algae
blooms and a less-severe dead zone.
The forecast also looks at
algae blooms in the Potomac River
and underwater grass beds in the
upper bay, Tangier Sound and the
Potomac River.
For grasses, there shouldn't
be much change in the upper bay
and Tangier, but the Potomac should
see some improvement after losing
grasses last year.
Algae blooms in the Potomac
should start in early summer,
last one to two months and could
extend for 10 to 20 miles at
the peak. That, too, is considered
average.
The forecast is in its
third year. The idea is to
use data to predict future
conditions, rather than always
looking at what already has
happened.
Dr. Dennison, the
project leader for the forecast,
said he knows of only two
other similar efforts in
the world - a dead zone prediction
in the Gulf of Mexico and
an algae bloom prediction
in the Baltic Sea.
"It's an emerging
science," he said.
Read the full summer
forecast at www.eco-check.org.
Published June 11, 2007, The Capital,
Annapolis, Md.
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