Large part of Chesapeake Bay is dead zone
July 27, 2005Scientists this month reported finding more than a third of Chesapeake Bay -- the United States' largest estuary -- is a low-oxygen "dead zone."
That, the scientists told the Baltimore Sun, means the bay might experience one of its most unhealthy summers on record.
"The things we love to eat out of the bay will not do well with this kind of summer," Bill Dennison, a University of Maryland ecologist, told the newspaper. "Oxygen is a crucial part of the environment for the fish and crabs and oysters, and having low oxygen or no oxygen is just as devastating for them as bulldozing a forest is for other creatures."
"Dead zones" form when fertilizer and other pollutants high in nitrogen and phosphorus are washed by rain into the bay. The compounds feed an explosive growth of algae, which, in turn, die and rot. Bacteria devouring such decay consume oxygen, suffocating marine life.
A study of the bay from Virginia to its origin at the Susquehanna River in northern Maryland found about 36 percent of the bay's central stem had less than 5 milligrams per liter of dissolved oxygen -- the minimum level needed by aquatic life.
Copyright 2005 by United Press International
Sep 29, 2009 |
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