Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Entire DC Network
Dinitrogen Fixation And Release Of Ammonium And Dissolved Organic Nitrogen By Trichodesmium Ims101, Mr Mulholland, Da Bronk, Dg Capone
Dinitrogen Fixation And Release Of Ammonium And Dissolved Organic Nitrogen By Trichodesmium Ims101, Mr Mulholland, Da Bronk, Dg Capone
VIMS Articles
Two methods used to measure dinitrogen (N-2) fixation (acetylene reduction and N-15(2) uptake) often result in different N-2 fixation rates. Part of the discrepancy may arise from the observation that Trichodesmium can release a fraction of their recently fixed N-2 as dissolved organic nitrogen (DON) and/or ammonium (NH4+). To resolve outstanding issues regarding N-2 fixation and the production of dissolved combined nitrogen (N) by Trichodesmium, we conducted a comprehensive analysis of N-2 fixation and the production of DON and NH4+ in cultures of Trichodesmium IMS101. We performed N-15(2) uptake experiments in parallel with acetylene (C2H2) reduction assays, and measured production …
Linking Watershed Loading And Basin-Level Carrying Capacity Models To Evaluate The Effects Of Land Use On Primary Production And Shellfish Aquaculture, Mark Luckenbach, Harry V. Wang
Linking Watershed Loading And Basin-Level Carrying Capacity Models To Evaluate The Effects Of Land Use On Primary Production And Shellfish Aquaculture, Mark Luckenbach, Harry V. Wang
VIMS Articles
Aquaculture production of hard clams, Mercenaria mercenaria, in the lower Chesapeake Bay, Virginia, U.S.A., has increased dramatically within the last decade. In recent years concern has been raised that some growing areas may be approaching the exploitation carrying capacity for clam production. Preliminary calculations indicate that large-scale intensive clam aquaculture may be controlling nutrient and phytoplankton dynamics in this system. To date, carrying capacity models have not been applied to this system, but we are in the process of building models for that purpose. Moreover changing land use in the watersheds surrounding the clam-producing areas raises the need for an …
Examination Of Reference Concentration Under Waves And Currents On The Inner Shelf, Guan-Hong Lee, W. Brian Dade, Carl T. Friedrichs, Chris E. Vincent
Examination Of Reference Concentration Under Waves And Currents On The Inner Shelf, Guan-Hong Lee, W. Brian Dade, Carl T. Friedrichs, Chris E. Vincent
VIMS Articles
[ 1] We examine reference concentration using three different data sets of near-bed suspended sediment concentration observed under combined waves and currents. The data include observations made at 15 and 20 m depth off Dounreay, Scotland, UK, and observations obtained at 13 m depth off Duck, North Carolina, USA. These data accommodate different dynamic conditions ( from wave-dominated conditions at Dounreay to wind-driven, current-dominated conditions at Duck) and sediment properties ( median size of bed sediment ranging from 120 to 350 mm). Near-bed concentration profiles to elevations of about 80 cm were obtained using acoustic backscatter sensors with 1 cm …