This satellite image shows brown water flowing into Chesapeake Bay from the Susquehanna River. The Susquehanna, which enters Chesapeake Bay at its northern end, carries 40 percent of the nitrogen that flows into the Bay - the largest single source. There is so much nitrogen in the northern Bay that algae have all the 'fertilizer' they need, and changes in streamflow do little or nothing to affect the growth of algal blooms. (NASA / Robert Simmon / Landsat-7 / UMD Global Land Cover Facility)

By Timothy B. Wheeler, The Baltimore Sun
9:43 a.m. EDT, May 19, 2010 While the Chesapeake Bay’s overall health improved slightly last year, the rivers that drain much of the Baltimore area remain in such poor shape that they earn a “failing grade,” University of Maryland scientists reported Tuesday. The bay as a whole improved its overall grade from a C-minus to a C on the annual report card prepared by the University of Maryland Center for Environmental Science. Eight of the bay’s major rivers systems in Maryland and Virginia had at least marginally better conditions for fish and crabs last year, while four remained unchanged. But two tributaries, the Baltimore-area’s Patapsco and Back rivers, bucked the trend and actually worsened. The two rivers, which empty into the bay around Baltimore harbor, continued to register the worst conditions among all the Chesapeake’s tributaries, rating the only “F” on the report card for the second straight year. … The Patapsco and Back rivers, in particular, need help because they are in the most dire situation, said William C. Dennison, vice president of the environmental science center and the coordinator of the bay health report card. “That’s going to be the heaviest lifting we have in the whole [bay] watershed.” … He noted that most streams and creeks that drain into the Patapsco and Back rivers are in poor or very poor condition, with portions of many actually buried under streets and parking lots. While water clarity improved by an average of 12 percent baywide, it didn’t improve at all in the Baltimore area rivers, which are so murky they’ve scored a zero for clarity over the past decade. …

Bay’s health improves slightly, scientists say