Scientists have been monitoring the levels of nitrogen, phosphorous and sediment at sites across the bay watershed since 1985. These are pollutants from runoff that smother life in the Bay.
According to the USGS, 70 percent of test sites showed improvement for nitrogen and phosphorous over the long term and 40 percent of sites showed improvement for sediment through 2009.
"Over the past 50 years, we've doubled the amount of people in the Bay watershed, but we're still seeing downward trends in the majority of sites," says Scott Phillips, Chesapeake Bay coordinator for the USGS.
That's in part due to ongoing renovations at wastewater treatment plants. Scientists say conservation measures dealing with runoff from stormwater and agriculture will take longer to appear. And they point out that "better" does not mean "good" -- more than half the streams in the area are in poor or very poor condition.Chesapeake Bay Report Card