Persistence of “urban” organics downstream favors dead-zone
formation
Each time it rains, runoff carries an earthy tea steeped
from leaf litter, crop residue, soil, and other organic materials into the
storm drains and streams that feed Chesapeake Bay.
A new study led by researchers at the Virginia Institute of
Marine Science reveals that land use in the watersheds from which this
“dissolved organic matter” originates has important implications for Bay water
quality, with the organic carbon in runoff from urbanized or heavily farmed
landscapes more likely to persist as it is carried downstream, thus
contributing energy to fuel low-oxygen “dead zones” in coastal waters.