Spatial and temporal variation in carbon storage in subtropical seagrass meadows
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Date
2016-10-17
Journal Title
Journal ISSN
Volume Title
Publisher
World Seagrasses Association
Abstract
Seagrass meadows are one of three habitats that serve as marine carbon sinks, preserving up to thousands of years of carbon stored in their sediments. However, seagrass meadows are highly threatened and are continuing to decline worldwide. Seagrass management and conservation initiatives require adequate understanding of the spatial and temporal variability of carbon storage in these ecosystems, which is currently limited. This study aimed to identify how varying environmental and biological conditions influence spatial and temporal variability of carbon storage in subtropical seagrass meadows. Seagrass biomass and sediment cores were collected between the years 2012 and 2013 at multiple locations across a water quality gradient within Moreton Bay, Australia. The number of cores collected were 298 biomass cores, 298 shallow sediment cores, and 20 deeper sediment cores of up to 2 m sediment depth. Sediment carbon content and seagrass structural complexitywere determined for each location. Environmental variables were determined from field data (water quality) and modelled data (wave height). Spatial variability of carbon content was found among sites and linked to variations in seagrass canopy complexity, water turbidity, depth and wave energy. Sediment isotopic composition varied among locations, indicating variations in the contribution of carbon sources. Seasonal variability was limited and overshadowed by spatial variability. Millennial variation was observed, by dating the deeper sediment cores using 210PB and 14C. Carbon content, vertical accretion, isotopic composition, and carbon accumulation rates varied through the sediment column in Moreton Bay and were higher following European settlement. This study provides comprehensive results on spatial and temporal variability of seagrass sediments in Moreton Bay, which provides useful information for the developmentand implementation of blue carbon conservation and management initiatives.
Description
Keywords
Gramineae, Aquatic ecosystems, Carbon sinks, Australia, Ecosystems, Environment, Sediments, Wave forces
Citation
Samper-Villarreal, J., Lovelock, C. E., Saunders, M. I., Roelfsema, C., Hua, Q., & Mumby, P. J. (2016). Presented to 12th International Seagrass Biology Workshop (ISBW12), 17-23 October 2015, Nant Gwrtheyrn, Wales, (pp. 60). Retrieved from https://orbi.uliege.be/bitstream/2268/203574/1/ISBW12%20Programme.pdf