Bioavailability of dissolved organic nitrogen and carbon from nine rivers in the eastern United States

نویسندگان

  • Tracy N. Wiegner
  • Sybil P. Seitzinger
  • Patricia M. Glibert
  • Deborah A. Bronk
چکیده

Dissolved organic nitrogen (DON) and carbon (DOC) often dominate the dissolved nitrogen and organic carbon fluxes from rivers, yet they are not considered to affect coastal water quality because of their assumed refractory nature. The objective of this study was to quantify DON and DOC bioavailability to bacteria in 9 rivers on the east coast of the United States during a 6 d dark bioassay experiment. Water was collected from the freshwater portion of a forest stream in New Jersey (Forest 17a), and from the Bass (New Jersey), Delaware (New Jersey), Hudson (New York), Altamaha (Georgia), Savannah (Georgia), Pocomoke (Maryland), Choptank (Maryland), and Peconic (New York) Rivers during base-flow conditions. DON concentrations ranged from 1 to 35 μM and comprised 8 to 94% of the total dissolved nitrogen (TDN) in these rivers. Bioassay results indicate that 23% (±4) of the DON (2 ± 1 μM) was bioavailable in all the rivers except the Bass and Pocomoke, where no DON consumption was measured. Of the TDN consumed by bacteria, DON comprised 43% (±6), demonstrating that DON is an important nitrogen source for bacteria. In contrast, only 4% (±1) of DOC (12 ± 3 μM), was bioavailable in the 9 rivers. Percent-wise, 8 times more DON was consumed relative to DOC in 6 of the rivers, demonstrating that DON cycles faster than DOC. Overall, our study demonstrates that DON is an important part of the TDN pool that needs to be incorporated into coastal nitrogen loading budgets because it is bioavailable on the order of days.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Seasonal bioavailability of dissolved organic carbon and nitrogen from pristine and polluted freshwater wetlands

We examined the chemical composition and bioavailability of dissolved organic carbon (DOC) and nitrogen (DON) from two pristine and two polluted cedar bog wetlands across three seasons. Pristine and polluted wetlands differed in DOC and DON concentrations, chemical characteristics, and bioavailability. DOC and DON concentrations were higher in the polluted than in the pristine wetlands. In cont...

متن کامل

Export of dissolved carbonaceous and nitrogenous substances in rivers of the "Water Tower of Asia".

Rivers are critical links in the carbon and nitrogen cycle in aquatic, terrestrial, and atmospheric environments. Here riverine carbon and nitrogen exports in nine large rivers on the Tibetan Plateau - the "Water Tower of Asia" - were investigated in the monsoon season from 2013 to 2015. Compared with the world average, concentrations of dissolved inorganic carbon (DIC, 30.7mg/L) were high in r...

متن کامل

Spatial and temporal variability in sediment denitrification within an agriculturally influenced reservoir

Reservoirs are intrinsically linked to the rivers that feed them, creating a river–reservoir continuum in which water and sediment inputs are a function of the surrounding watershed land use. We examined the spatial and temporal variability of sediment denitrification rates by sampling longitudinally along an agriculturally influenced river–reservoir continuum monthly for 13 months. Sediment de...

متن کامل

Limnol. Oceanogr., 44(6), 1999, 1477–1485

Access to bioavailable nitrogen often limits primary production in marine and freshwater ecosystems. Around 70% of nitrogen transported by rivers worldwide consists of dissolved organic nitrogen (DON), but its bioavailability has been poorly investigated. To assess the potential bacterial growth on DON, we developed a bioassay employing natural DON and bacterial inocula in medium manipulated to...

متن کامل

Riparian deforestation, stream narrowing, and loss of stream ecosystem services.

A study of 16 streams in eastern North America shows that riparian deforestation causes channel narrowing, which reduces the total amount of stream habitat and ecosystem per unit channel length and compromises in-stream processing of pollutants. Wide forest reaches had more macroinvertebrates, total ecosystem processing of organic matter, and nitrogen uptake per unit channel length than contigu...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2006