Large dead zones predicted for Gulf, Chesapeake Bay

Jul 14, 2008

Record-setting "dead zones" in the Gulf of Mexico and Chesapeake Bay appear likely this summer, according to new forecasts from a University of Michigan researcher.

Donald Scavia, a professor at the U-M School of Natural Resources and Environment (SNRE), makes the annual forecasts using models driven by nutrient load estimates from the U.S. Geological Survey.

In this year's Chesapeake Bay Hypoxic Volume Forecast, Scavia predicts a summer hypoxic volume of 9.9 cubic kilometers (2.4 cubic miles), the sixth-highest on record. If the upper value of the forecast range of 12.3 cubic kilometers (3 cubic miles) is reached, it will be the highest on record. The Bay is about 200 miles long on the East Coast and stretches from Maryland to Virginia. It supports thousands of species of plants, fish and animals. The Bay's oxygen levels are critical in determining the health of its ecosystem.

Given recent massive flooding of cities and farms in the Mississippi River basin, the Gulf of Mexico Hypoxia Area Forecast is for the dead zone to cover between 21,500 and 22,500 square kilometers (8,400-8,800 square miles) of bottom waters along the Louisiana-Texas coast. If the prediction bears out, it will be the largest on record.

"The growth of these dead zones is an ecological time bomb," said Scavia, who is also director of the Michigan Sea Grant program based at SNRE. "Without determined local, regional, and national efforts to control them, we are putting major fisheries at risk." According to Scavia, the best way to shrink the dead zones is to reduce the amount of nitrogen and phosphorous flowing into these water basins.

Hypoxia refers to the loss of oxygen in water, which then leads to conditions unsustainable for aquatic life. The Chesapeake Bay and Gulf of Mexico dead zones form each spring as nitrogen and phosphorus loads from farm fertilizers, atmospheric deposition and wastewater treatment plants stimulate algae blooms. These blooms eventually die and sink to the bottom, where bacteria decompose them and consume most of the oxygen. The zones dissipate each fall as changes in water currents and temperatures mix and reaerate the water—only to return the next spring.

Scavia originally developed the model to estimate the nitrogen-load reductions needed to reach particular hypoxia goals. Several years ago, he discovered that the model could also forecast the dead zone size for an upcoming season, based on the average January-May nitrogen loads for the Chesapeake Bay, and average May-June loads for the Mississippi River basin.

Source: University of Michigan

Explore further: Five anthropogenic factors that will radically alter northern forests in 50 years

add to favorites email to friend print save as pdf

Related Stories

Recommended for you

More, bigger wildfires burning western US, study shows

14 hours ago

Wildfires across the western United States have been getting bigger and more frequent over the last 30 years – a trend that could continue as climate change causes temperatures to rise and drought to become ...

User comments : 4

Adjust slider to filter visible comments by rank

Display comments: newest first

earls
3.7 / 5 (3) Jul 14, 2008
As a native of Maryland, this really sucks. Things just seem to keep getting worse for the bay. I know they're working hard or restoration, but it may just be too late.

Once the crabs are gone they may be gone for good. :(
Mercury_01
1.5 / 5 (2) Jul 14, 2008
Thats why I got the Verizon network.
jonnyboy
2.7 / 5 (3) Jul 27, 2009
OOPS
earls
1 / 5 (1) Jul 28, 2009
lol

More news stories

Six Nepalese dead, six missing in Everest avalanche

At least six Nepalese climbing guides have been killed and six others are missing after an avalanche struck Mount Everest early Friday in one of the deadliest accidents on the world's highest peak, officials ...

China says massive area of its soil polluted

A huge area of China's soil covering more than twice the size of Spain is estimated to be polluted, the government said Thursday, announcing findings of a survey previously kept secret.

There's something ancient in the icebox

Glaciers are commonly thought to work like a belt sander. As they move over the land they scrape off everything—vegetation, soil, and even the top layer of bedrock. So scientists were greatly surprised ...

Clean air: Fewer sources for self-cleaning

Up to now, HONO, also known as nitrous acid, was considered one of the most important sources of hydroxyl radicals (OH), which are regarded as the detergent of the atmosphere, allowing the air to clean itself. ...

Leeches help save woman's ear after pit bull mauling

(HealthDay)—A pit bull attack in July 2013 left a 19-year-old woman with her left ear ripped from her head, leaving an open wound. After preserving the ear, the surgical team started with a reconnection ...

Venture investments jump to $9.5B in 1Q

Funding for U.S. startup companies soared 57 percent in the first quarter to a level not seen since 2001, as venture capitalists piled more money into an increasing number of deals, according to a report due out Friday.