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Full-Text Articles in Life Sciences

Chemical And Toxicological Characterization Of The Lower Mobjack Bay, York River, Virginia Segment Of The Chesapeake Bay, Morris H. Roberts Jr., Mark A. Richards, Peter F. Delisle Dec 2003

Chemical And Toxicological Characterization Of The Lower Mobjack Bay, York River, Virginia Segment Of The Chesapeake Bay, Morris H. Roberts Jr., Mark A. Richards, Peter F. Delisle

Reports

The Chesapeake Bay segment called Lower Mobjack Bay Lower York River Virginia was found to have insufficient data to characterize in 1999. Therefore this area was selected for a chemical, toxicological, benthic community characterization study of the sediments in 2002. The segment was divided into 3 strata: the lower York River, the Poquoson River, and Back River, each with 4 randomly selected stations. Samples were collected in October 2002 for evaluation of conditions.

There were few significant chemical exceedances of the ER-L or ER-M in the three strata and no toxicologically effects from exposure to sediment samples from any stratum. …


The Chesapeake Bay : A Synopsis, William J. Hargis Jr. Jan 2003

The Chesapeake Bay : A Synopsis, William J. Hargis Jr.

Reports

No abstract provided.


Microbial Dynamics And Biogeochemistry In The North Pacific Subtropical Gyre, Matthew J. Church Jan 2003

Microbial Dynamics And Biogeochemistry In The North Pacific Subtropical Gyre, Matthew J. Church

Dissertations, Theses, and Masters Projects

The research presented in this dissertation describes the influence of planktonic bacterial growth on upper ocean organic matter dynamics in the North Pacific Subtropical Gyre (NPSG). Examination of the temporal dynamics in dissolved organic matter (DOM) was coupled with investigations that targeted the influence of heterotrophic bacterial production (HBP) on organic matter fluxes in the NPSG. Nine cruises to the Hawaii Ocean Time-series field site Station ALOHA revealed that HBP accounted for a large flux of organic carbon in the upper ocean of the NPSG. HBP was significantly enhanced by sunlight, with photoenhancement of HBP accounting for 3.2 mol C …


Availability Of Humic Nitrogen To Phytoplankton, Jason Holt See Jan 2003

Availability Of Humic Nitrogen To Phytoplankton, Jason Holt See

Dissertations, Theses, and Masters Projects

The chemical, physical, and biological factors affecting the bioavailability of humic nitrogen (N) to coastal phytoplankton were examined. Historically, humic substances have largely been considered biologically refractory, and humic-N is though to be unavailable biologically without prior oxidation via photochemical cleavage or remineralization by bacteria. This is due in part to the high aromaticity and low N content of humic substances. This dissertation investigates whether these assumptions are valid, and whether humic substances may be a more important source of N to the coastal phytoplankton community than previously believed. The research consisted of four main parts. First, changes in the …