Abstract
Sedimentary phosphorus (P) composition was investigated in Effingham Inlet, a fjord located on the west coast of Vancouver Island in Barkley Sound. Solid-state 31P nuclear magnetic resonance (NMR) spectroscopy was applied to demineralized sediment samples from sites overlain by oxic and anoxic bottom waters. The two sites were similar in terms of key diagenetic parameters, including the mass accumulation rate, integrated sulfate reduction rate, and bulk sediment organic carbon content. In contrast, P benthic fluxes were much higher at the anoxic site. 31P NMR results show that P esters and phosphonates are the major organic P species present at the surface and at depth in sediments at both sites. Polyphosphates were only found in the surface sediment of the site overlain by oxic waters. The varying stability of polyphosphates in microorganisms under different redox conditions may, in part, explain their distribution as well as differences in P flux between the two sites.
Highlights
PhosphorusPis an essential and in many cases limiting nutrient sustaining marine primary productivity
Solid-state 31P NMR spectra of demineralized sediment samples from Effingham Inlet are presented in Figs. 5 and 6
The abundance of P esters in natural organic matter is undoubtedly related to the synthesis of these compounds by all living organisms, and they are typically the most abundant compound class seen in studies from both marine and terrestrial environments
Summary
PhosphorusPis an essential and in many cases limiting nutrient sustaining marine primary productivity. The burial of P compounds resistant to remineralization during diagenesis is a significant sink in the global marine P budget.. The preferential regeneration of P from sediments overlain by anoxic bottom waters has been suggested from studies of solid phase P distribution.. The preferential regeneration of P from sediments overlain by anoxic bottom waters has been suggested from studies of solid phase P distribution.15–20 This hypothesis remains controversial, as other studies propose that the net effect of anoxia on P release is not as significant.. This hypothesis remains controversial, as other studies propose that the net effect of anoxia on P release is not as significant.1,5,21–23 This controversy may be resolved in part with a better understanding of redox sensitive mechanisms involved in P cycling Evidence from the direct measurement of benthic fluxes or fluxes calculated from pore water profiles suggests that the presence of anoxic bottom waters enhances the release of Pas compared to N and Cfrom organic matter. The preferential regeneration of P from sediments overlain by anoxic bottom waters has been suggested from studies of solid phase P distribution. this hypothesis remains controversial, as other studies propose that the net effect of anoxia on P release is not as significant. This controversy may be resolved in part with a better understanding of redox sensitive mechanisms involved in P cycling
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
