Dynamics of dissolved organic carbon and total dissolved nitrogen in Maryland's coastal bays

摘要: Abstract Dissolved organic matter (DOM) provides nutrients and energy subsidies for harmful algal blooms in Maryland's Coastal Bays (MCBs, USA). The composition, sources dynamics of DOM MCBs are not well known. In this study, dissolved carbon (DOC) total nitrogen (TDN) were monitored monthly over a period one year (July 2011 to June 2012) at 13 stations the MCBs. Absorption fluorescence spectroscopy used characterize composition track terrestrial inputs versus aquatic DOM. Results show that DOC TDN concentrations (187–501 μM 19.4–40.6 μM) comparable eutrophic coastal waters United States but much higher than mid-Atlantic Bight. This suggests source ocean. Spatially, nearshore sites had relatively terrestrially-derived aromatic (indicated by high humification index) bays directly connected Atlantic Ocean. Seasonally, from main body (Chincoteague Assawoman Bays) displayed pronounced seasonal pattern with highest values occurring summer. Protein-like algal/bacterial biological freshness index or was also summer then decreased gradually until April. site later spring, probably due inputs. Conversely, smaller faster flushing rates (Newport, Sinepuxent Isle Wight April, watershed spring peak apparent MCBs, which have longer times (indicating stronger uptake). study eutrophic, shallow such as consists large fraction protein-like components local algal/microbial during enhanced primary productivity is likely fueled agricultural urban land use spring. Further insights regarding spatiotemporal variations controls abundance, can be helpful guiding prioritizing restoration efforts reducing eutrophication water quality degradation.