Oysters are a sign of bay health - they are only at 1 percent of historical levels. Oysters are threatened by disease, but also sediment pollution.
By Sabri Ben-Achour
Scientists say the Chesapeake Bay is showing signs of improvement, though pollution remains a serious problem. More and more of that pollution is coming from urban areas.
There are two bright spots in the bay: more crabs than seen in decades and aquatic grasses are spreading. Neither are at healthy levels but they're better than before. But only 12 percent of the Chesapeake Bay has enough oxygen for healthy life, according to the Chesapeake Bay Program. One major reason - pollution in the form of nitrogen, phosphorous, and sediment. Richard Batuik, Associate Director of Science for the Program, explains the connection.
"That excess pollution goes in there creates algae, that algae dies off, and as it decomposes it robs oxygen out of the water column," says Batuik.
One big contributor is all the pavement that multiplies as our region grows. Nitrous oxides and ammonia from air pollution are deposited on parking lots and roads. When it rains, they're shunted into the rivers instead of getting filtered through the soil. Another major source of urban pollution is fertilizer.
"The millions and millions of acres of back yards, front yards that people want to put a lot of fertilizer on spring fall summer," he says.
Scientists say that of all the myriad sources of pollution going into the bay, urban sources are the only ones that are increasing.
You can learn more about the Chesapeake Bay's health here