Knauss legislative fellowships in Congress help build careers — and they're fun and educational. See our video and fact sheet for details.
The Maryland Sea Grant bookstore is closed from December 10 to January 3.
Research Publications: UM-SG-RS-2011-11
Title:
Tracking nonpoint source nitrogen pollution in human-impacted watersheds
Year:
2011Authors:
Kaushal, SS; Groffman, PM; Band, LE; Elliott, EM; Shields, CA; Kendall, CSource:
Environmental Science & Technology 45 ( 19 ) : 8225 - 8232DOI:
10.1021/es200779eAbstract:
Nonpoint source nitrogen (N) pollution is a leading contributor to U.S. water quality impairments. We combined watershed N mass balances and stable isotopes to investigate fate and transport of nonpoint N in forest, agricultural, and urbanized watersheds at the Baltimore Long-Term Ecological Research site. Annual N retention was 55%, 68%, and 82% for agricultural, suburban, and forest watersheds, respectively. Analysis of delta N-15-NO3-, and delta O-18-NO3- indicated wastewater was an important nitrate source in urbanized streams during baseflow. Negative correlations between delta N-15-NO3- and delta O-18-NO3- in urban watersheds indicated mixing between atmospheric deposition and wastewater, and N source contributions changed with storm magnitude (atmospheric sources contributed similar to 50% at peak storm N loads). Positive correlations between delta N-15-NO3- and delta O-18-NO3- in watersheds suggested denitrification was removing septic system and agriculturally derived N, but N from belowground leaking sewers was less susceptible to denitrification. N transformations were also observed in a storm drain (no natural drainage network) potentially due to organic carbon inputs. Overall, nonpoint sources such as atmospheric deposition, wastewater, and fertilizer showed different susceptibility to watershed N export. There were large changes in nitrate sources as a function of runoff, and anticipating source changes in response to climate and storms will be critical for managing nonpoint N pollution.
Related Research Project(s) Funded by Maryland Sea Grant:
Maryland Sea Grant Topic(s):
'Related Research Project(s)' link to details about research projects funded by Maryland Sea Grant that led to this publication. These details may include other impacts and accomplishments resulting from the research.
'Maryland Sea Grant Topic(s)' links to related pages on the Maryland Sea Grant website.
Program Announcements
News and Blogs
Featured Fellow
Leone Yisrael is a cephalopod-loving scuba diver, cook, and loves to try new activities. She conducts genetic analysis and fieldwork at the Smithsonian Environmental Research Center through the Coastal Disease Ecology Lab.
Featured Research Project
Developing a habitat model for mysids, an important link in Chesapeake Bay food webs
Mysids are important mesozooplankton prey for many species of fish in Chesapeake Bay and are an important link in transferring energy from lower to upper trophic levels. Mysids also serve as biological vectors for benthic-pelagic coupling due to their diel vertical migration and omnivorous prey-switching behavior, which makes mysids important regulators of food web architecture. Despite their central role in coastal food webs, surprisingly little is known about mysid ecology and dynamics in Chesapeake Bay.
