Coastal wetlands in Tampa Bay, Florida, are important ecosystems that deliver a variety of ecosystem services. Key to ecosystem functioning is wetland response to sea-level rise through accumulation of mineral and organic sediment. The organic sediment within coastal wetlands is composed of carbon sequestered over the time scale of the wetland’s existence. This study was conducted to provide information on soil accretion and carbon storage rates across a variety of coastal ecosystems that was utilized in the Tampa Bay Blue Carbon Assessment (ESA, 2017; linkage below). Ten sediment cores were collected from six Tampa Bay wetland sites in October 2015 (maximum core length 40 centimeters). Three main vegetation types were targeted for core collection: salt marsh, dominated by Juncus and Spartina alternaflora; mangrove, including Rhizophora mangle, Laguncularia racemosa and/or Avicennia germinans; and young mangrove, where wetlands were created within the last three decades. An additional surface sediment sample was collected from a salt barren, as this site was not conducive to coring. Marsh surface elevations were measured at each site (ranging from 0.771 meters to 1.462 meters relative to NAVD88) to determine the marsh boundaries within current tidal conditions. Continuous Rate of Supply age models, based on lead-210 and cesium-137 isotope analysis, were constructed to evaluate how vertical accretion and carbon burial rates have changed during the past century. Over that time, accretion rates were very similar for each ecosystem: restored marsh sites (2.5 mm per year), followed by the salt marshes (2.7 mm per year) and mature mangroves (3.2 mm per year). The resulting carbon burial rates over the past century vary as a function of vegetation type, with mature mangroves burying on average 163 grams carbon per square meter per year, compared to young (restoring) mangroves with an average of 94 grams carbon per square meter per year and the salt marsh with an average of 64 grams carbon per square meter per year . This dataset also includes dry bulk density (0.02 - 1.70 grams per cubic centimeter), percent carbon (0.32 %-39.08 %), and percent loss on ignition (0.66 % – 80.2 %) from a sub-set of core sections in order to assess possible correlative relationships among these parameters. https://estuaries.org/wp-content/uploads/2019/02/FINAL_Tampa-Bay-Blue-Carbon-Assessment-Report-updated-compressed.pdf

Mangrove restoration efforts often focus on planting seedlings and ignore the underlying physical parameters causing mangrove loss, such as disruption to the hydrological regime. In order to determine success of hydrological restoration, baseline data need to be collected and assessed from a degraded mangrove system undergoing hydrological restoration. Sample collection occurred within the Rookery Bay National Estuarine Research Reserve, FL along a gradient of deforestation, from a heavily degraded dead (no canopy) zone to a transitional zone, and into a full canopy zone and compared to a natural (reference) full canopy mangrove environment nearby. Data included faunal abundance and diversity, stable isotope (carbon and nitrogen), and a suite of environmental variables, such as salinity, temperature, dissolved oxygen and grain size. These baseline data provide critical information on the ecosystem functioning that can be used to track community changes in mangrove habitats following hydrological restoration.

Mangrove restoration efforts often focus on planting seedlings and ignore the underlying physical parameters causing mangrove loss, such as disruption to the hydrological regime. In order to determine success of hydrological restoration, baseline data need to be collected and assessed from a degraded mangrove system undergoing hydrological restoration. Sample collection occurred within the Rookery Bay National Estuarine Research Reserve, FL along a gradient of deforestation, from a heavily degraded dead (no canopy) zone to a transitional zone, and into a full canopy zone and compared to a natural (reference) full canopy mangrove environment nearby. Data included faunal abundance and diversity, stable isotope (carbon and nitrogen), and a suite of environmental variables, such as salinity, temperature, dissolved oxygen and grain size. These baseline data provide critical information on the ecosystem functioning that can be used to track community changes in mangrove habitats following hydrological restoration.

Sediment cores (1 m in depth) were collected at each of three mangrove sites at J.N. Ding Darling National Wildlife Refuge on Sanibel Island, Florida. At each site, one core was collected in the hydrogeomorphic zone called the fringe, which is the area directly adjacent to the ocean. The other core was collected in the zone called the basin, which is the large area, often behind a small berm, that receives less direct tidal energy. All cores were sectioned and measured for sectional volume, dry weight and % organic carbon (OC) by weight.

The San Juan Bay Estuary, Puerto Rico, contains mangrove forests that store significant amounts of organic carbon in soils and biomass. There is a strong urbanization gradient across the estuary, from the highly urbanized and clogged Caño Martin Peña in the western part of the estuary, a series of lagoons in the center of the estuary, and a tropical forest reserve (Piñones) in the easternmost part with limited urbanization. We collected sediment cores to determine carbon burial rates and vertical sediment accretion from five sites in the San Juan Bay Estuary. Cores were radiometrically-dated using lead-210 and the Plum age model. Sites had soil C burial rates ranging from 50 grams per meter squared per year (g m-2 y-1) in the San José lagoon to 632 g m-2 y-1 in the Caño Martin Peña in recent decades. Soil accretion and carbon burial rates were greater in recent decades (1970-2016) compared to historic decades (1930-1970) at some of the forest mangrove sites (i.e. Caño Martin Peña). Apparently, not only urbanization, but site-specific flushing patterns, landscape setting, and soil characteristics affected soil C burial rates. This dataset can help evaluate how differences in urbanization (low in the forest preserve to high in the clogged canal), flushing, and landscape setting influence soil accretion and carbon burial in urban, tropical mangrove forests.

Results of radiocarbon dating of deep-sea (500 m to 700 m) black corals are presented. These corals were collected off the southeastern United States as part of the Southeastern United States Deep-Sea Corals (SEADESC) Initiative.

68 Holocene-aged corals from reef cores collected throughout the Florida Keys reef tract (FKRT) were dated using a combination of U-series and radiocarbon techniques to quantify the millennial-scale variability in the local radiocarbon reservoir age (ΔR) of the shallow water environments of south Florida. ΔR provides a measure of the deviation of local radiocarbon concentrations of marine environments from the global average and can be used as a tracer of oceanic circulation and local hydrology. U.S. Geological Survey (USGS) scientists combined coral-based estimates of ΔR, using statistical modeling, to reconstruct millennial-scale variability in ΔR at locations on the FKRT with (“nearshore”) and without (“open ocean”) terrestrial influence. USGS scientists also used the models to provide temporally-explicit estimates of ΔR that can be used in radiocarbon calibrations of marine samples from the region. In Version 1.0 of the USGS data release (Toth and others, 2017) associated with this metadata record, derivedthe coral-based estimates of ΔR were derived using data from the Marine13 radiocarbon calibration curve (Reimer and others, 2013). In version 2.0, the ΔR estimates were instead derived using the Marine20 radiocarbon calibration curve (Heaton and others, 2020). For further information regarding data collection and analysis methods refer to Toth and others (2017).

68 Holocene-aged corals from reef cores collected throughout the Florida Keys reef tract (FKRT) were dated using a combination of U-series and radiocarbon techniques to quantify the millennial-scale variability in the local radiocarbon reservoir age (ΔR) of the shallow water environments of south Florida. ΔR provides a measure of the deviation of local radiocarbon concentrations of marine environments from the global average and can be used as a tracer of oceanic circulation and local hydrology. U.S. Geological Survey (USGS) scientists combined coral-based estimates of ΔR, using statistical modeling, to reconstruct millennial-scale variability in ΔR at locations on the FKRT with (“nearshore”) and without (“open ocean”) terrestrial influence. USGS scientists also used the models to provide temporally-explicit estimates of ΔR that can be used in radiocarbon calibrations of marine samples from the region. In Version 1.0 of the USGS data release (Toth and others, 2017) associated with this metadata record, derivedthe coral-based estimates of ΔR were derived using data from the Marine13 radiocarbon calibration curve (Reimer and others, 2013). In version 2.0, the ΔR estimates were instead derived using the Marine20 radiocarbon calibration curve (Heaton and others, 2020). For further information regarding data collection and analysis methods refer to Toth and others (2017).

Holocene-aged corals from reef cores collected throughout the Florida Keys reef tract (FKRT) were dated using a combination of U-series and radiocarbon techniques to quantify the millennial-scale variability in the local radiocarbon reservoir age (ΔR) of the shallow water environments of south Florida. ΔR provides a measure of the deviation of local radiocarbon concentrations of marine environments from the global average and can be used as a tracer of oceanic circulation and local hydrology. U.S. Geological Survey (USGS) scientists combined coral-based estimates of ΔR, using statistical modeling, to reconstruct millennial-scale variability in ΔR at locations on the FKRT with (“nearshore”) and without (“open ocean”) terrestrial influence. USGS scientists also used the models to provide temporally-explicit estimates of ΔR that can be used in radiocarbon calibrations of marine samples from the region. For further information regarding data collection and analysis methods refer to Toth and others (2016, 2017). This research is a part of the USGS Coral Reef Ecosystem Studies Project (http://coastal.er.usgs.gov/crest/).

Holocene-aged corals from reef cores collected throughout the Florida Keys reef tract (FKRT) were dated using a combination of U-series and radiocarbon techniques to quantify the millennial-scale variability in the local radiocarbon reservoir age (ΔR) of the shallow water environments of south Florida. ΔR provides a measure of the deviation of local radiocarbon concentrations of marine environments from the global average and can be used as a tracer of oceanic circulation and local hydrology. U.S. Geological Survey (USGS) scientists combined coral-based estimates of ΔR, using statistical modeling, to reconstruct millennial-scale variability in ΔR at locations on the FKRT with (“nearshore”) and without (“open ocean”) terrestrial influence. USGS scientists also used the models to provide temporally-explicit estimates of ΔR that can be used in radiocarbon calibrations of marine samples from the region. For further information regarding data collection and analysis methods refer to Toth and others (2016, 2017). This research is a part of the USGS Coral Reef Ecosystem Studies Project (http://coastal.er.usgs.gov/crest/).