title: Do ENSO and Coastal Development Enhance Coastal Burial of Terrestrial Carbon?
abstract: Carbon cycling on the east coast of Australia has the potential to be strongly affected by El Niño-Southern Oscillation (ENSO) intensification and coastal development (industrialization and urbanization). We performed paleoreconstructions of estuarine sediments from a seagrass-dominated estuary on the east coast of Australia (Tuggerah Lake, New South Wales) to test the hypothesis that millennial-scale ENSO intensification and European settlement in Australia have increased the transfer of organic carbon from land into coastal waters. Our data show that carbon accumulation rates within coastal sediments increased significantly during periods of maximum millennial-scale ENSO intensity ("super-ENSO") and coastal development. We suggest that ENSO and coastal development destabilize and liberate terrestrial soil carbon, which, during rainfall events (e.g., La Niña), washes into estuaries and becomes trapped and buried by coastal vegetation (seagrass in this case). Indeed, periods of high carbon burial were generally characterized as having rapid sedimentation rates, higher content of fine-grained sediments, and increased content of wood and charcoal fragments. These results, though preliminary, suggest that coastal development and ENSO intensification--both of which are predicted to increase over the coming century--can enhance capture and burial of terrestrial carbon by coastal ecosystems. These findings have important relevance for current efforts to build an understanding of terrestrial-marine carbon connectivity into global carbon budgets.
authors.affiliation: Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Broadway, New South Wales 2007, Australia.|Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood, Victoria 3125, Australia.
authors.forename: Peter I
authors.initials: PI
authors.lastname: Macreadie
authors.affiliation: School of Geosciences, University of Newcastle, Callaghan 2308, Australia.
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Rolph
authors.affiliation: School of Geosciences, University of Newcastle, Callaghan 2308, Australia.
authors.forename: Ron
authors.initials: R
authors.lastname: Boyd
authors.affiliation: Department of Earth Sciences, Carleton University, Ottawa, Ontario K1S 5B6, Canada.
authors.forename: Claudia J
authors.initials: CJ
authors.lastname: Schröder-Adams
authors.affiliation: School of the Environment, University of Technology Sydney, Broadway, New South Wales 2007, Australia.
authors.forename: Charles G
authors.initials: CG
authors.lastname: Skilbeck
mesh_terms: D001315:Australia; D058572:Carbon Footprint; D060106:Lakes; D008962:Models, Theoretical