Watch CBS News

Smaller Low-Oxygen Levels Predicted For Chesapeake

WASHINGTON (AP) -- Researchers say low oxygen levels should affect smaller-than-average areas of the Chesapeake Bay this year.

Scientists said Tuesday that they are expecting smaller-than-average hypoxic levels this year, meaning a smaller-than-average "dead zone" in the nation's largest estuary.

Hypoxic zones with very low oxygen and anoxic zones with no oxygen are caused by excessive nutrient pollution from fertilizer runoff from farm fields and lawns.

Nutrients like nitrogen and phosphorous can spur algae blooms in the water, consuming oxygen needed by marine life. Weather conditions, including wind speed, wind direction, precipitation and temperature, also play a role in dead zones.

Researchers say the Chesapeake dead zones, which have varied considerably in recent years, threaten an effort to restore the Bay's water quality and enhance its production of crabs, oysters, and other fisheries.

(Copyright 2013 by The Associated Press. All Rights Reserved.)

View CBS News In
CBS News App Open
Chrome Safari Continue
Be the first to know
Get browser notifications for breaking news, live events, and exclusive reporting.