Abstract
‘Blue carbon’ ecosystems—seagrasses, tidal marshes, and mangroves—serve as dense carbon sinks important for reducing atmospheric greenhouse gas concentrations, yet only recently have stock estimates emerged. We sampled 96 blue carbon ecosystems across the Victorian coastline (southeast Australia) to quantify total sediment stocks, variability across spatial scales, and estimate emissions associated with historical ecosystem loss. Mean sediment organic carbon (Corg) stock (±SE) to a depth of 30 cm was not significantly different between tidal marshes (87.1 ± 4.90 Mg Corg ha−1) and mangroves (65.6 ± 4.17 Mg Corg ha−1), but was significantly lower in seagrasses (24.3 ± 1.82 Mg Corg ha−1). Location (defined as an individual meadow, marsh, or forest) had a stronger relationship with Corg stock than catchment region, suggesting local-scale conditions drive variability of stocks more than regional-scale processes. We estimate over 2.90 million ± 199,000 Mg Corg in the top 30 cm of blue carbon sediments in Victoria (53% in tidal marshes, 36% in seagrasses, and 11% in mangroves) and sequestration rates of 22,700 ± 5510 Mg Corg year−1 (valued at over $AUD1 million ± 245,000 year−1 based on the average price of $AUD12.14 Mg CO2 eq−1 at Australian Emissions Reduction Fund auctions). We estimate ecosystem loss since European settlement may equate to emissions as high as 4.83 million ± 358,000 Mg CO2 equivalents (assuming 90% remineralization of stocks), 98% of which was associated with tidal marsh loss, and what would have been sequestering 9360 ± 2500 Mg Corg year−1. This study is among the first to present a comprehensive comparison of sediment stocks across and within coastal blue carbon ecosystems. We estimate substantial and valuable carbon stocks associated with these ecosystems that have suffered considerable losses in the past and need protection into the future to maintain their role as carbon sinks.
References
Alongi DM. 2012. Carbon sequestration in mangrove forests. Carbon Management 3:313–22.
Anisfeld SC, Hill TD. 2012. Fertilization Effects on Elevation Change and Belowground Carbon Balance in a Long Island Sound Tidal Marsh. Estuaries and Coasts 35:201–11.
Baldock JA, Hawke B, Sanderman J, MacDonald LM. 2013. Predicting contents of carbon and its component fractions in Australian soils from diffuse reflectance mid-infrared spectra. Soil Research 51:577–95.
Ball D, Soto-Berelov M, Young P. 2014. Historical seagrass mapping in Port Phillip Bay, Australia. Journal of Coastal Conservation 18:257–72.
Blake S, Ball D. 2001a. Seagrass Mapping of Port Phillip Bay. Queenscliff.
Blake S, Ball D. 2001b. Victorian Marine Habitat Database: Seagrass Mapping of Western Port. Queenscliff.
Blake S, Roob R, Patterson E. 2000. Seagrass Mapping of Victoria’s Minor Inlets. Marine and Freshwater Resources Institute.
Boon PI, Allen T, Brook J, Carr G, Frood D, Harty C, Hoye J, Mcmahon, Andrew Mathews S, Rosengren N, Sinclair S, White M, Yugovic J. 2011. Mangroves and coastal saltmarsh of Victoria: distribution, condition, threats and management.
Bouillon S, Dahdouh-Guebas F, Rao AVVS, Koedam N, Dehairs F. 2003. Sources of organic carbon in mangrove sediments: variability and possible ecological implications. Hydrobiologia 495:33–9.
Breithaupt JL, Smoak JM, Smith TJ, Sanders CJ, Hoare A. 2012. Organic carbon burial rates in mangrove sediments: strengthening the global budget. Global Biogeochemical Cycles 26:1–11.
Bridgewater P. 1982. Mangrove vegetation of the southern and western Australian coastline. Mangrove ecosystems in Australia.
Campbell JE, Lacey E, Decker R, Crooks S, Fourqurean JW. 2014. Carbon storage in seagrass beds of Abu Dhabi. Estuaries and Coasts: United Arab Emirates.
Chen S, Torres R, Goñi M. 2015. The Role of Salt Marsh Structure in the Distribution of Surface Sedimentary Organic Matter. Estuaries and Coasts.
Chmura GL, Anisfeld SC, Cahoon DR, Lynch JC. 2003. Global carbon sequestration in tidal, saline wetland soils. Global Biogeochemical Cycles 17:n/a–n/a.
Chmura GL, Coffey A, Crago R. 2001. Variation in Surface Sediment Deposition on Salt Marshes in the Bay of Fundy. Journal of Coastal Research 17:221–7.
Connor RF, Chmura GL, Beecher CB. 2001. Carbon accumulation in Bay of Fundy salt marshes: Implications for restoration of reclaimed marshes. Global Biogeochemical Cycles 15:943–54.
Darby FA, Turner RE. 2008. Below- and aboveground biomass of Spartina alterniflora: response to nutrient addition in a Louisiana salt marsh. Estuaries and Coasts 31:326–34.
Donato DC, Kauffman JB, Murdiyarso D, Kurnianto S, Stidham M, Kanninen M. 2011. Mangroves among the most carbon-rich forests in the tropics. Nature Geoscience 4:293–7.
Duarte CM, Losada IJ, Hendriks IE, Mazarrasa I, Marbà N. 2013. The role of coastal plant communities for climate change mitigation and adaptation. Nature Climate Change 3:961–8.
Duarte CM. 2002. The future of seagrass meadows. Environmental Conservation 29:192–206.
Duke NC, Ball MC, Ellison JC. 1998. Factors influencing biodiversity and distributional gradients in mangroves. Global Ecology and Biogeography Letters 7:27–47.
Fourqurean JW, Duarte CM, Kennedy H, Marbà N, Holmer M, Mateo MA, Apostolaki ET, Kendrick G, Krause-Jensen D, McGlathery KJ, Serrano O. 2012. Seagrass ecosystems as a globally significant carbon stock. Nature Geoscience 5:505–9.
Giri C, Ochieng E, Tieszen LL, Zhu Z, Singh A, Loveland T, Masek J, Duke N. 2011. Status and distribution of mangrove forests of the world using earth observation satellite data. Global Ecology and Biogeography 20:154–9.
Granek E, Ruttenberg BI. 2008. Changes in biotic and abiotic processes following mangrove clearing. Estuarine, Coastal and Shelf Science 80:555–62.
Hopkinson CS, Cai W-J, Hu X. 2012. Carbon sequestration in wetland dominated coastal systems—a global sink of rapidly diminishing magnitude. Current Opinion in Environmental Sustainability 4:186–94.
Howard J, Hoyt S, Isensee K, Pidgeon E, Telszewski M, editors. 2014. Coastal Blue Carbon: Methods for assessing carbon stocks and emissions factors in mangroves, tidal salt marshes, and seagrass meadows. Conservation International, Intergovernmental Oceanographic Commission of UNESCO, International Union for Conservation of Nature. Arlington, Virginia, USA.
Kauffman JB, Heider C, Cole TG, Dwire K, Donato DC. 2011. Ecosystem carbon stocks of micronesian mangrove forests. Wetlands 31:343–52.
Kelleway JJ, Saintilan N, Macreadie PI, Ralph PJ. 2016. Sedimentary Factors are Key Predictors of Carbon Storage in SE Australian Saltmarshes. Ecosystems 19:865–80.
Kelleway JJ, Saintilan N, Macreadie PI, Skilbeck CG, Zawadzki A, Ralph PJ. 2015. Seventy years of continuous encroachment substantially increases ‘blue carbon’ capacity as mangroves replace intertidal salt marshes. Global Change Biology:n/a–n/a.
Kristensen E, Bouillon S, Dittmar T, Marchand C. 2008. Organic carbon dynamics in mangrove ecosystems: A review. Aquatic Botany 89:201–19.
Lavery PS, Mateo M-Á, Serrano O, Rozaimi M. 2013. Variability in the carbon storage of seagrass habitats and its implications for global estimates of blue carbon ecosystem service. PloS one 8:e73748.
Lawrence A, Baker E, Lovelock C. 2012. Optimising and managing coastal carbon: Comparative sequestration and mitigation opportunities across Australia’s landscapes and land uses.
Lear R, Turner T. 1977. Mangroves of Australia. St Lucia: University of Queensland Press 84p-Illus.
Li Y, Wang L, Zhang W, Zhang S, Wang H, Fu X, Le Y. 2010. Variability of soil carbon sequestration capability and microbial activity of different types of salt marsh soils at Chongming Dongtan. Ecological Engineering 36:1754–60.
Livesley SJ, Andrusiak SM. 2012. Temperate mangrove and salt marsh sediments are a small methane and nitrous oxide source but important carbon store. Estuarine, Coastal and Shelf Science 97:19–27.
Lovelock CE, Cahoon DR, Friess DA, Guntenspergen GR, Krauss KW, Reef R, Rogers K, Saunders ML, Sidik F, Swales A, Saintilan N, Thuyen LX, Triet T. 2015. The vulnerability of Indo-Pacific mangrove forests to sea-level rise. Nature 526:559-U217.
Lovelock CE, Ruess RW, Feller IC. 2011. CO2 efflux from cleared mangrove peat. PloS one 6:e21279.
Macreadie PI, Baird ME, Trevathan-Tackett SM, Larkum AWD, Ralph PJ. 2014. Quantifying and modelling the carbon sequestration capacity of seagrass meadows—A critical assessment. Marine Pollution Bulletin 83:430–9.
Mateo M, Romero J, Perez M, Littler M, Littler D. 1997. Dynamics of millenary organic deposits resulting from the growth of Mediterranean seagrass Posidonia oceanica. Estuarine, Coastal and Shelf Science 44:103–10.
Mcleod E, Chmura GL, Bouillon S, Salm R, Björk M, Duarte CM, Lovelock CE, Schlesinger WH, Silliman BR. 2011. A blueprint for blue carbon: toward an improved understanding of the role of vegetated coastal habitats in sequestering CO2. Frontiers in Ecology and the Environment 9:552–60.
Minasny B, McBratney AB, Mendonça-Santos ML, Odeh IOA, Guyon B. 2006. Prediction and digital mapping of soil carbon storage in the Lower Namoi Valley. Australian Journal of Soil Research 44:233–44.
Morris JT, Bradley PM. 1999. Effects of nutrient loading on the carbon balance of coastal wetland sediments. Limnology and Oceanography 44:699–702.
Murray BC, Pendleton L, Jenkins W, Sifleet S (2011) Green payments for blue carbon economic incentives for protecting threatened coastal habitats.
Olivier JGJ, Muntean M, Peters JAHW. 2015. Trends in global CO2 emissions: 2015 report.
Pedersen MØ, Serrano O, Mateo MÁ, Holmer M. 2011. Temperature effects on decomposition of a Posidonia oceanica mat. Aquatic Microbial Ecology 65:169–82.
Pendleton L, Donato DC, Murray BC, Crooks S, Jenkins WA, Sifleet S, Craft C, Fourqurean JW, Kauffman JB, Marbà N, Megonigal P, Pidgeon E, Herr D, Gordon D, Baldera A. 2012. Estimating global ‘blue carbon’ emissions from conversion and degradation of vegetated coastal ecosystems. PloS one 7:e43542.
Ricart AM, York PH, Rasheed M a., Pérez M, Romero J, Bryant C V., Macreadie PI. 2015. Variability of sedimentary organic carbon in patchy seagrass landscapes. Marine Pollution Bulletin.
Rogers K, Wilton KM, Saintilan N. 2006. Vegetation change and surface elevation dynamics in estuarine wetlands of southeast Australia. Estuarine, Coastal and Shelf Science 66:559–69.
Roob R, Ball D. 1997. Victorian marine habitat database: Gippsland Lakes seagrass mapping. Queenscliff.
Roob R, Morris P, Werner G. 1998. Victorian marine habitat database: Corner Inlet & Nooramunga seagass mapping. Queenscliff.
Saintilan N, Rogers K, Mazumder D, Woodroffe C. 2013. Allochthonous and autochthonous contributions to carbon accumulation and carbon store in southeastern Australian coastal wetlands. Estuarine, Coastal and Shelf Science 128:84–92.
Saintilan N, Rogers K. 2013. The significance and vulnerability of Australian saltmarshes: Implications for management in a changing climate. Marine and Freshwater Research 64:66–79.
Saintilan N. 2004. Relationships between estuarine geomorphology, wetland extent and fish landings in New South Wales estuaries. Estuarine, Coastal and Shelf Science 61:591–601.
Schlesinger WH, Lichter J. 2001. Limited carbon storage in soil and litter of experimental forest plots under increased atmospheric CO2. Nature 411:466–9.
Scott DB, Greenberg DA. 1983. Relative sea-level rise and tidal development in the Fundy tidal system. Canadian Journal of Earth Sciences 20:1554–64.
Semeniuk V. 1994. Predicting the effect of sea-level rise on mangroves in northwestern Australia. Journal of Coastal Research 10:1050–76.
Serrano O, Lavery PS, Rozaimi M, Mateo MÁ. 2014. Influence of water depth on the carbon sequestration capacity of seagrasses. Global Biogeochemical Cycles 28:950–61.
Siikamäki J, Sanchirico JN, Jardine S, McLaughlin D, Morris D. 2013. Blue carbon: coastal ecosystems, their carbon storage, and potential for reducing emissions. Environment: Science and Policy for Sustainable Development 55:14–29.
Sinclair S, Boon P. 2012. Changes in the area of coastal marsh in Victoria since the mid 19th century. Cunninghamia 12:153–76.
Smart RM, Barko JW. 1980. Nitrogen nutrition and salinity tolerance of Distichlis spicata and Spartina alterniflora. Ecology 61:630–8.
Sousa AI, Lillebø AI, Pardal M, Caçador I. 2010a. Productivity and nutrient cycling in salt marshes: Contribution to ecosystem health. Estuarine, Coastal and Shelf Science 87:640–6.
Sousa AI, Lillebø AI, Pardal M, Caçador I. 2010b. The influence of Spartina maritima on carbon retention capacity in salt marshes from warm-temperate estuaries. Marine Pollution Bulletin 61:215–23.
Spalding M, Blasco F, Field C. 1997. World Atlas of Mangroves. Okinawa: The International Society for Mangrove Ecosystems.
Tu Q, Yang S, Zhou Q, Yang J. 2015. Sediment transport and carbon sequestration characteristics along mangrove fringed coasts. Acta Oceanologica Sinica 34:21–6.
Turner R. 1976. Geographic variations in salt marsh macrophyte production: a review. Contributions in Marine Science 20:47–68.
Warry F, Hindell J (2009) Review of Victorian seagrass research with emphasis on Port Phillip Bay. Heidelberg, Victoria.
Waycott M, Duarte CM, Carruthers TJB, Orth RJ, Dennison WC, Olyarnik S, Calladine A, Fourqurean JW, Heck KL, Hughes R, Kendrick G, Kenworthy WJ, Short FT, Williams SL. 2009. Accelerating loss of seagrasses across the globe threatens coastal ecosystems. Proceedings of the National Academy of Sciences of the United States of America 106:12377–81.
Yang J, Gao J, Liu B, Zhang W. 2014. Sediment deposits and organic carbon sequestration along mangrove coasts of the Leizhou Peninsula, southern China. Estuarine, Coastal and Shelf Science 136:3–10.
Yu KW, Wang ZP, Vermoesen A, Patrick WH, Van Cleemput O. 2001. Nitrous oxide and methane emissions from different soil suspensions: Effect of soil redox status. Biology and Fertility of Soils 34:25–30.
Acknowledgements
We thank our volunteers, especially Ellen Rochelmeyer, Chris Taylor, and Catherine Cavallo. We thank the Victorian Coastal Catchment Management Authorities (CMAs) for their support and funding: Marty Gent & Glenelg Hopkins CMA, Chris Pitfield & Corangamite CMA, Emmaline Froggatt & Port Phillip Westernport CMA, Belinda Brennan & West Gippsland CMA, and Rex Candy & East Gippsland CMA. Funding was also provided by an Australian Research Council DECRA Fellowship (DE130101084) and an Australian Research Council Linkage Project (LP160100242). CJEL also thanks the University of Technology Sydney for scholarship support.
Author information
Authors and Affiliations
Corresponding author
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Ewers Lewis, C.J., Carnell, P.E., Sanderman, J. et al. Variability and Vulnerability of Coastal ‘Blue Carbon’ Stocks: A Case Study from Southeast Australia. Ecosystems 21, 263–279 (2018). https://doi.org/10.1007/s10021-017-0150-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10021-017-0150-z