Carbon, Nitrogen, and Phosphorus Stoichiometry and Eutrophication in River Thames Tributaries, UK. Issue 1 (1st September 2017)

• Record Type: Journal Article
• Authors: Smith, D. R.; Jarvie, H. P.; Bowes, M. J.
• Is Part Of: Agricultural & environmental letters. Volume 2:Issue 1(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-09-01
• Subjects: Agriculture -- Periodicals; Agriculture -- Environmental aspects -- Periodicals; Agriculture; Agriculture -- Environmental aspects; Periodicals; 630
• DOI: 10.2134/ael2017.06.0020
• Languages: English
• ISSNs: 2471-9625

Abstract

Abstract : Core Ideas: A novel graphical method for displaying C/N/P stoichiometry is presented. Five River Thames tributaries were used to assess the utility of stoichiometric plots. <13% total dissolved P limited chlorophyll a to <30 μg L −1 . Primary productivity in aquatic systems relies on carbon (C), nitrogen (N), and phosphorus (P) availability, with a reference stoichiometric ratio of 106 C/16 N/1 P, known as the Redfield ratio. This paper presents a methodology to visualize river water C/N/P stoichiometry and examine phytoplankton response. Redfield total dissolved C/N/P concentration ratios (TDC/TDNR /TDPR ) from five River Thames tributaries were plotted in a ternary diagram, allowing relationships between nutrient stoichiometry, total P concentrations, and chlorophyll a, as a surrogate for phytoplankton biomass, to be explored. Chlorophyll a concentrations above 100 μg L −1 were not observed below 14% TDPR, and concentrations above 30 μg L −1 were not observed below 13% TDPR . This indicates a potentially lower TDPR limit for highly eutrophic waters. These rivers are C and N rich, and this methodology should be applied to a wider range of rivers to explore C, N and P thresholds across different river typologies.