Archive for Caribbean

Seagrass carbon dynamics: Gulf of Mexico

Posted by mmaheigan 
· Thursday, March 1st, 2018 

Seagrasses have died-off in great numbers, resulting in the release of stored carbon. Seagrasses represent a substantive and relatively unconstrained North American and Caribbean Sea blue carbon sink in the tropical Western Hemisphere. Fine-scale estimates of regional seagrass carbon stocks, as well as carbon fluxes from anthropogenic disturbances and natural processes and gains in sedimentary carbon from seagrass restoration are currently lacking for the bulk of tropical Western Hemisphere seagrass systems.

To address this knowledge gap, in the subtropics and tropics, a recent study yielded estimates of organic carbon (Corg) stocks, losses, and restoration gains from several seagrass beds around the Gulf of Mexico (GoM). GoM-wide seagrass natural Corg stocks were estimated to be ~37.2–37.5Tg Corg. A unique method involving quadruplicate sampling in naturally-occurring, restored, continually-historically barren, and previously-disturbed-now-barren sites provided the first available Corg loss measurements for subtropical-tropical seagrasses. GoM Corg losses were slow, occurring over multiple years, and differed between sites, depending on disturbance type. Mean restored seagrass bed Corg stocks exceeded those of natural seagrass beds, underscoring the importance of seagrass restoration as a viable carbon sequestration strategy. For restored seagrass areas, the older the restoration site, the greater the Corg stock.

Organic carbon stocks for Gulf of Mexico sediments for the top 20 cm of sediment in always barren, impacted barren, natural seagrass, and restored seagrass sites. Natural and restored seagrass beds had significantly higher organic carbon stocks than impacted barren or always barren sediments.

Seagrass restoration appears to be an important tool for climate-change mitigation. In the USA and throughout the tropics and subtropics, restoration could reduce sedimentary carbon leakage and bolster total blue carbon stores, while facilitating increased fisheries and shoreline stability. Although well-planned and executed restoration of seagrass is more difficult than mangroves or marshes, there are >1 million hectares of degraded seagrass habitats that could be restored, which would greatly increase blue carbon sinks and support diverse marine species that rely on seagrass for habitat and food.

 

Authors:
Anitra Thorhaug (Yale School of Forestry)
Helen M. Poulos (Earth Sci., Wesleyan Univ.)
Jorge López-Portillo (Inecol, Mexico)
Timothy C.W. Ku (Earth Sci., Wesleyan Univ.)
Graeme P. Berlyn (Yale School of Forestry)

Filter by Keyword

abundance acidification africa air-sea interactions alkalinity allometry ammonium AMOC anoxia anoxic Antarctic anthropogenic carbon aragonite saturation arctic arsenic Atlantic Atlantic modeling atmospheric CO2 atmospheric nitrogen deposition authigenic carbonates autonomous platforms bacteria BATS benthic bgc argo bio-go-ship bio-optical bioavailability biogeochemical cycles biogeochemical models biogeochemistry Biological Essential Ocean Variables biological pump biological uptake biophysics bloom blooms blue carbon bottom water boundary layer buffer capacity C14 CaCO3 calcification calcite carbon-climate feedback carbon-sulfur coupling carbon cycle carbon dioxide carbon sequestration Caribbean CCA CCS changi changing marine ecosystems changing ocean chemistry chemoautotroph chesapeake bay chl a chlorophyll circulation climate change CO2 coastal darkening coastal ocean cobalt Coccolithophores community composition conservation cooling effect copepod coral reefs currents cyclone DCM decomposers decomposition deep convection deep ocean deep sea coral deoxygenation depth diagenesis diatoms DIC diel migration dimethylsulfide dinoflagellate dissolved inorganic carbon dissolved organic carbon DOC DOM domoic acid dust DVM earth system models ecosystem state eddy Education Ekman transport emissions ENSO enzyme equatorial regions error ESM estuarine and coastal carbon fluxes estuary euphotic zone eutrophication evolution export EXPORTS extreme events extreme weather events faecal pellets filter feeders filtration rates fire fish Fish carbon fisheries floats fluid dynamics fluorescence food webs forams freshening freshwater frontal zone functional role future oceans geochemistry geoengineering GEOTRACES glaciers gliders global carbon budget global warming go-ship grazing greenhouse gas Greenland groundwater Gulf of Maine Gulf of Mexico Gulf Stream gyre harmful algal bloom high latitude human food human impact hurricane hydrothermal hypoxia ice age ice cores ice cover industrial onset inverse circulation iron iron fertilization isotopes jellies katabatic winds kelvin waves krill kuroshio land-ocean continuum larvaceans lateral transport LGM lidar ligands light light attenuation lipids mangroves marine carbon cycle marine heatwave marine snowfall marshes Mediterranean meltwater mesopelagic mesoscale metagenome metals methane methods microbes microlayer microorganisms microscale microzooplankton midwater mixed layer mixed layers mixotrophy modeling mode water molecular diffusion MPT multi-decade NAAMES NASA NCP net community production new technology nitrate nitrogen nitrogen fixation nitrous oxide north atlantic north pacific nutricline nutrient budget nutrient cycling nutrient limitation nutrients OA ocean-atmosphere ocean acidification ocean carbon uptake and storage ocean color ocean observatories ODZ oligotrophic omics OMZ open ocean optics organic particles overturning circulation oxygen pacific paleoceanography particle flux pCO2 PDO peat pelagic pH phenology phosphorus photosynthesis physical processes physiology phytoplankton plankton POC polar regions pollutants prediction primary productivity Prochlorococcus proteins pteropods pycnocline radioisotopes remineralization remote sensing repeat hydrography residence time resource management respiration resuspension rivers rocky shore Rossby waves Ross Sea ROV salinity salt marsh satell satellite scale seafloor seagrass sea ice sea level rise seasonal patterns sea spray seaweed sediments sensors shelf system shells ship-based observations shorelines silicate sinking particles size SOCCOM soil carbon southern ocean south pacific spatial covariations speciation SST subduction submesoscale subpolar subtropical sulfate surf surface surface ocean Synechococcus teleconnections temperate temperature temporal covariations thermocline thermohaline thorium tidal time-series time of emergence top predators total alkalinity trace elements trace metals trait-based transfer efficiency transient features trophic transfer tropical turbulence twilight zone upper ocean upper water column upwelling US CLIVAR validation velocity gradient ventilation vertical flux vertical migration vertical transport volcano water clarity water quality western boundary currents wetlands winter mixing zooplankton

Copyright © 2021 - OCB Project Office, Woods Hole Oceanographic Institution, 266 Woods Hole Rd, MS #25, Woods Hole, MA 02543 USA Phone: 508-289-2838  •  Fax: 508-457-2193  •  Email: ocb_news@us-ocb.org

link to nsflink to noaalink to WHOI

Funding for the Ocean Carbon & Biogeochemistry Project Office is provided by the National Science Foundation (NSF) and the National Aeronautics and Space Administration (NASA). The OCB Project Office is housed at the Woods Hole Oceanographic Institution.