Journal article
Factors controlling seasonal CO2 and CH4 emissions in three tropical mangrove-dominated estuaries in Australia
Estuarine, Coastal and Shelf Science, Vol.215, pp.69-82
31/12/2018
Metrics
64 Record Views
UN Sustainable Development Goals (SDGs)
This output has contributed to the advancement of the following goals:
Source: InCites
Abstract
CO2 and CH4 emissions from estuaries of the Southern Hemisphere are greatly under-represented in global estuary emission estimates. This study quantifies seasonal pCO2 and CH4 concentrations and emissions along the salinity gradient of three tropical mangrove-dominated estuaries in Australia. A combination of approaches (i.e. carbon stable isotopes, groundwater inputs, riverine contribution, freshwater flushing times) was used to assess the spatial and seasonal variable factors that controlled the estuary surface water CO2 and CH4 concentrations and hence emissions. Overall, CO2 and CH4 emissions ranged from 21.6 to 110.4 mmol m−2 d−1 and 40.3 to 1047.1 μmol m−2 d−1, respectively, and were within or at the high end compared to estuaries in Australia and globally. In the Johnstone River estuary, high emissions were predominantly driven by groundwater and riverine carbon inputs with exports of CO2 and CH4 to the ocean expected in the wet season. In the Fitzroy River estuary and Constant Creek estuary, in situ production and terrestrial carbon inputs were likely the main factors controlling CO2 and CH4 emissions. The contribution of riverine CO2 may be more important to overall CO2 emissions than the riverine CH4 to overall CH4 emissions in estuaries. The relative contribution of in situ production, the exchange with adjacent coastal habitats (i.e. mangroves, inter-tidal flats), and terrestrial, riverine and groundwater inputs in the wet and in the dry season determined whether CO2 and CH4 were fully ventilated within the estuaries or exported to the open ocean. The revised global estimate for estuary CO2 emission of the latitude 0 to 23.5 °S is 52.1 ± 16.1 mmol m−2 d−1, which is 15% higher than a recent estimate of this latitudinal region. [Display omitted] •Emissions were within or at the high end of estuaries from Australia and globally.•CO2 and CH4 fluxes were higher in the wet season compared to the dry season.•Factors controlling CO2 and CH4 emissions varied spatially and seasonally.•The riverine contribution determined whether CO2 and CH4 were exported to the ocean.•Groundwater, terrestrial and coastal carbon inputs contributed to estuary emissions.
Details
- Title
- Factors controlling seasonal CO2 and CH4 emissions in three tropical mangrove-dominated estuaries in Australia
- Creators
- Judith A Rosentreter (Corresponding Author) - Southern Cross UniversityD T Maher - Southern Cross UniversityD V Erler - Southern Cross UniversityR Murray - Southern Cross UniversityB D Eyre - Southern Cross University
- Publication Details
- Estuarine, Coastal and Shelf Science, Vol.215, pp.69-82
- Publisher
- Elsevier Ltd
- Grant note
- This project was funded by the Great Barrier Reef Foundation's Resilient Coral Reefs Successfully Adapting to Climate Change research and development program in collaboration with the Australian Government, and by Australian Research Council Grants DE150100581, DP160100248, and LP150100519.
- Identifiers
- 991012831988202368
- Copyright
- © 2018 Elsevier Ltd. All rights reserved.
- Academic Unit
- Faculty of Science and Engineering; School of Environment, Science and Engineering; Science; Centre for Coastal Biogeochemistry; Southern Cross GeoScience
- Language
- English
- Resource Type
- Journal article