Wednesday, May 11, 2005

For the Chesapeake Bay, the largest estuary in the United States, a first-time-ever “water quality forecast” was issued Monday for the upcoming summer season by the Chesapeake Bay Program. The eastern mid-Atlantic region’s heavy spring rainfalls are predicted to increase nutrient levels in bay waters, leading to oxygen eating algae blooms and leaving deep water dead zones.

Project leader William Dennison, of the University of Maryland Center for Environmental Studies said, “The forecast indicates that recent weather conditions and heavy pollutant loads could lead to a bad summer for the Bay.” The prediction is for this to be the fourth-worst season for dissolved oxygen in two decades.

The Chesapeake Bay Program launched the new forecast to build on a base of environmental data gathered over the last two decades as water quality concerns have grown. The forecast is meant to be a proactive tool that provides resource managers with information that can be used to guide policies for the bay’s protection and restoration.

Cars, fertilizer, human and animal wastes, industrial and agricultural pollutants all play a part. “This means that we need to do a lot more to reduce phosphorus and nitrogen pollution from getting into the bay,” said Beth McGee, of the Chesapeake Bay Foundation. “The biggest source of pollution in the bay is agriculture, and we’ve got to find a way to provide farmers with more resources to manage the land better.”

Nutrient rich pollutants composed mainly of nitrogen and phosphorous come from far away places carried by rivers, and nearby the bay from farm and metropolitan runoff. They collect in the huge bay and meet tidal flows from the ocean.

Algae feed off the nutrients, and they are either consumed by aquatic life or sink at the end of their life cycle. With such an abundant food source, algae blooms can cover large surfaces of water and choke off sunlight to underwater plants. Later when the plants die, the process of their decomposition on the bottom consumes oxygen to a state where the water becomes anoxic, and unable to support life.

As notorious as weather forecasters are for often being wrong, it should come as no surprise if this first forecasting step by the federally funded program misses its mark. Forces such as heavy storms or hurricanes, which churn water, would have an effect. Excessive wind and unexpected precipitation, or nutrient level jumps, would also contribute.