Conference presentation
Novel use of cavity ring-down spectrometry to investigate aquatic carbon cycling from microbial to ecosystem scales
Australian Marine Sciences Association Conference , 50th (Gold Coast, Australia, 07/07/2013 - 11/07/2013)
09/07/2013
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Abstract
Development of cavity ring-down spectroscopy (CRDS) has enabled real-time monitoring of carbon stable isotope ratios of CO2 and CH4 in air, allowing for a greater understanding of terrestrial biogeochemical carbon cycling. To date this technology has only been used in a handful of aquatic applications. Here we show that this technology can be used in a number of ways to determine aquatic carbon cycling processes from the microbial to eco system scale under in situ and laboratory conditions. At the microbial scale, we demonstrate that the processing (mineralization) of deposited phytodetritus proceeds on the time scale of minutes. At the organism scale, we demonstrate how isotope fractionation factors and light respiration rates can be determined by incubating macroalgae in a 13C-DIC enriched medium over a diel cycle and continuously measuring dissolved CO2 concentration and 13C-CO2 using a closed loop gas equilibration device. At the community level a similar system was employed using a benthic chamber over a seagrass bed, and at the ecosystem scale, continuous measurements were made at the mouth of a mangrove creek for 40 hours, and during a survey along an estuary. Calculations of δ13C-DIC based on CRDS measured δ13C-CO2 and published fractionation factors were in excellent agreement with measured δ13C-DIC using IRMS indicating that no additional sample treatment is required for accurately determining δ13C-DIC of the aquatic samples.
Details
- Title
- Novel use of cavity ring-down spectrometry to investigate aquatic carbon cycling from microbial to ecosystem scales
- Creators
- Damien T Maher - Southern Cross UniversityIsaac R Santos - Southern Cross UniversityMatheus C Carvalho - Southern Cross UniversityBradley D Eyre - Southern Cross UniversityJasper RFW Leuven - Darwin Centre for BiogeosciencesJoanne M Oakes - Southern Cross University
- Conference
- Australian Marine Sciences Association Conference , 50th (Gold Coast, Australia, 07/07/2013 - 11/07/2013)
- Identifiers
- 991012845996202368
- Academic Unit
- Faculty of Science and Engineering; Centre for Coastal Biogeochemistry; National Marine Science Centre; School of Environment, Science and Engineering; Science
- Resource Type
- Conference presentation