Blue Carbon Storage Capacity of Temperate Eelgrass (Zostera marina) Meadows

Global Biogeochemical Cycles, Journal Year: 2018, Volume and Issue: 32(10), P. 1457 - 1475

Published: Sept. 19, 2018

Abstract Despite the importance of coastal ecosystems for global carbon budgets, knowledge their storage capacity and factors driving variability in is still limited. Here we provide an estimate on magnitude stocks within a widely distributed marine foundation species throughout its distribution area temperate Northern Hemisphere. We sampled 54 eelgrass ( Zostera marina ) meadows, spread across eight ocean margins 36° latitude, to determine abiotic biotic influencing organic (C org sediments. The C (integrated over 25‐cm depth) showed large ranged from 318 26,523 g C/m 2 with average 2,721 . projected obtained by extrapolating top 1 m sediment between 23.1 351.7 Mg C/ha, which line estimates other seagrasses blue ecosystems. Most variation was explained five environmental variables (sediment mud content, dry density degree sorting, salinity water depth), while plant attributes such as biomass shoot were less important stocks. Carbon isotopic signatures indicated that at most sites <50% derived seagrass, lower than reported previously seagrass meadows. high spatial urges caution geographical areas well species.

Language: Английский

---

Seagrass blue carbon spatial patterns at the meadow-scale

PLoS ONE, Journal Year: 2017, Volume and Issue: 12(4), P. e0176630 - e0176630

Published: April 27, 2017

Most information on seagrass carbon burial derives from point measurements, which are sometimes scaled by meadow area to estimate stocks; however, sediment organic (Corg) concentrations may vary with distance the edge, resulting in spatial gradients that affect accuracy of stock estimates. We mapped Corg throughout a large (6 km2) restored determine whether distribution patterns exist at different scales. The originated ≤1-acre plots seeded between 2001 and 2004, so we expected spatially according known age sample sites proximity edge. Applying autoregressive models allowed us control for autocorrelation quantify relative effects edge concentrations. found proximity, not age, significantly predicted meadow-scale distribution. also evaluated relationships variety specific explanatory variables, including site exposure, shoot density, grain size, bathymetry. Factors plot-scale, such as were significant controls Strong correlations Corg, suggest current attenuation increases fine-sediment deposition and, therefore, into meadow. By mapping pool, provide first accurate quantification an enhanced attributable restoration. top 12 cm bed contain 3660 t approximately 1200 more than equal bare sediment. net increase is concentrated low tidal velocities. Managers should account configuration velocity when estimating blue stocks. Our results large, contiguous store small patches.

Language: Английский

---

Fingerprinting Blue Carbon: Rationale and Tools to Determine the Source of Organic Carbon in Marine Depositional Environments

Frontiers in Marine Science, Journal Year: 2019, Volume and Issue: 6

Published: May 22, 2019

Blue carbon is the organic in oceanic and coastal ecosystems that captured on centennial to millennial timescales. Maintaining increasing blue an integral component of strategies mitigate global warming. Marine vegetated (especially seagrass meadows, mangrove forests, tidal marshes) are hotspots their degradation loss worldwide have reduced stocks increased CO2 emissions. Carbon markets, conservation restoration schemes aimed at enhancing sequestration avoiding greenhouse gas emissions, will be aided by knowing provenance fate carbon. We review critique current methods potential nascent track carbon, including: bulk isotopes, compound-specific biomarkers, molecular properties, environmental DNA. find most studies date used isotopes determine provenance, but this approach often cannot distinguish contribution different primary producers depositional marine environments. Based our assessment, we recommend application multiple complementary methods. In particular, use nitrogen lipids along with DNA a great identify source quantify sedimentary ecosystems. Despite promising these new techniques, further research needed validate them. This critical overview can inform future help underpin methodologies for implementation focused climate change mitigation schemes.

Language: Английский

---

Blue Carbon Stocks and Cross-Habitat Subsidies

Frontiers in Marine Science, Journal Year: 2020, Volume and Issue: 7

Published: June 11, 2020

Blue carbon ecosystems (including saltmarsh, mangrove, seagrass meadows, and other soft sediment habitats) play a valuable role in aquatic dynamics contribute significantly to global climate change mitigation. However, these habitats are undergoing rapid accelerating shifts extent due anthropogenic impactsstressors. Here, we demonstrate that blue stocks vary across cross-habitat subsidies of stocks. Using case study estuary from New Zealand, organic above ground biomass 100 cm varied between habitat types, saltmarsh (90 t ha-1), mangrove (46 (27 ha-1) unvegetated (26 ha-1). Despite being typically overlooked literature, contained the majority estuarine when adjusted for their large within (occupying 68.4% area containing 57% stocks). When were further refined based on δ13C δ15N mixing model results, coastal vegetation (saltmarsh, seagrass) was found provide important exchanges throughout estuary, including contributing an estimated 41% sediments, 51% total stock (yet occupying only 31.6% estuary). Given connected nature findings illustrate importance considering contribution cross both vegetated estuaries. This provides critical context assessing impact distributions impacts stressors.

Language: Английский

---

How can blue carbon burial in seagrass meadows increase long-term, net sequestration of carbon? A critical review

Environmental Research Letters, Journal Year: 2022, Volume and Issue: 17(9), P. 093004 - 093004

Published: Aug. 18, 2022

Abstract Blue carbon sequestration in seagrass meadows has been proposed as a low-risk, nature-based solution to offset emissions and reduce the effects of climate change. Although timescale burial is too short ancient fossil fuel carbon, it role play reaching net zero within modern cycle. This review documents discusses recent advances (from 2015 onwards) field blue carbon. The affected by species, meadow connectivity, sediment bioturbation, grainsize, energy local environment, calcium carbonate formation. rate organic can be calculated product accumulation below mixed layer concentration attributable seagrass. A combination biomarkers identify material more precisely than bulk isotopes alone. main threats related change are sea-level rise, leading shoreline squeeze, temperature particularly during extreme events such heat domes. In conclusion, some disagreement literature over methodology controls on likely results from real, regional differences seagrasses their habitat. Inter-regional collaboration could help resolve methodological provide robust understanding global meadows.

Language: Английский

---

Restoring blue carbon systems

Cambridge Prisms Coastal Futures, Journal Year: 2024, Volume and Issue: 2

Published: Jan. 1, 2024

Abstract Mangroves, tidal marshes and seagrasses have experienced extensive historical reduction in extent due to direct indirect effects of anthropogenic land use change. Habitat loss has contributed carbon emissions led foregone opportunities for sequestration, which are disproportionately large high ‘blue carbon’ stocks sequestration rates these coastal ecosystems. As such, there been a rapid increase interest using habitat restoration as climate change mitigation tool. This review shows that efforts able substantially blue stocks, while also having positive impact on various gaseous fluxes. However, increases spatially variable, biophysical factors such geomorphic setting. While potentially hundreds thousands hectares may be biophysically suitable restoration, activities still often conducted at small scales with mixed success. Maximizing potential gains through will require managers planners overcome the myriad socioeconomic governance constraints related tenure, legislation, target setting cost, push projects into locations unsuitable plant colonization.

Language: Английский

---

Non‐seagrass carbon contributions to seagrass sediment blue carbon

Limnology and Oceanography, Journal Year: 2017, Volume and Issue: 63(S1)

Published: Oct. 5, 2017

Abstract Non‐seagrass sources account for ∼ 50% of the sediment organic carbon (SOC) in many seagrass beds, a fraction that may derive from external matter (OM) advected into meadow and trapped by canopy or produced situ. If allochthonous fluxes are responsible non‐seagrass SOC given bed, this should decrease with distance perimeter. Identifying spatial origin is important closing budgets “blue carbon” offset‐credit accounting, but studies have yet to quantify map stocks source. We measured δ 13 C, 15 N, 34 S throughout large (6 km 2 ), restored Zostera marina (eelgrass) applied Bayesian mixing models total contributions possible autotroph sources, Z. , Spartina alterniflora benthic microalgae (BMA). accounted < 40% SOC, we did not find evidence outwelling fringing S. salt‐marsh OM advection bare subtidal areas. averaged 10% at sites both inside outside meadow. The BMA 51% was highest furthest subtidal‐meadow edge, indicative situ production. 210 Pb profiles confirmed meadow‐enhanced sedimentation facilitates burial BMA. Deducting contribution would underestimate fixation within Seagrass meadows can enhance burial, which likely accounts most stored beds.

Language: Английский

---

Particle capture by seagrass canopies under an oscillatory flow

Coastal Engineering, Journal Year: 2021, Volume and Issue: 169, P. 103972 - 103972

Published: Aug. 4, 2021

Although seagrass canopies are known to enhance particle sedimentation, there is still limited knowledge about how seagrasses modify the vertical distribution of sediment particles; especially when particles come from allochthonous sources. This study determined volume trapped by leaves, amount that remains in suspension both within and above canopy, deposited onto seabed. A set laboratory experiments were conducted which hydrodynamic conditions canopy densities varied mimic real field conditions. demonstrated quantified previously recorded observations concerning fate meadows. Seagrass meadows decreased suspended capturing on blades enhancing sedimentation However, whole increased with density reduced number canopy. The ecological implications significant, since a seabed covered vegetation, compared bare seabed, produced reduction improving water clarity. Furthermore, (compared substrates) enhanced denser was, greater

Language: Английский

---

Carbon accumulation and storage across contrasting saltmarshes of Scotland

Estuarine Coastal and Shelf Science, Journal Year: 2023, Volume and Issue: 282, P. 108223 - 108223

Published: Jan. 17, 2023

Saltmarshes are acknowledged to be "carbon hotspots" due their capacity trap and store large quantities of carbon (C) within soils potentially have the ability regulate climate over different timescales. In-turn governments international organizations now recognizing need include these intertidal ecosystems in national global C accounting. Yet, many regions, estimates organic (OC) storage rate at which OC is buried saltmarsh either do not exist or scale necessary for inclusion budgets. Here we bring together tools from across geosciences investigate quantity held soil above/belowground biomass, alongside accumulates source four contrasting Scottish saltmarshes. Using radiometric dating techniques it estimated that a between 29.1 198.1 g m−2 yr−1 study sites. In contrast, varies little sites with 73%–99% originating terrestrial/in situ sources; marine-derived plays minor role development stocks. average values derived possible make first-order stocks accumulation rates all Scotland's 240 mapped saltmarshes (58.68 km2). It Scotland habitat stores 1.15 ± 0.21 Mt supplemented by an additional 4385 481 tonnes each year.

Language: Английский

---

Reduced water motion enhances organic carbon stocks in temperate eelgrass meadows

Limnology and Oceanography, Journal Year: 2019, Volume and Issue: 64(6), P. 2389 - 2404

Published: May 14, 2019

Abstract Organic carbon (OC) storage in coastal vegetated ecosystems is increasingly being considered financing and climate change mitigation strategies. However, spatial heterogeneity these “blue carbon” stocks among within habitats has only recently been examined, despite its considerable implications. Seagrass meadows have potential to store significant amounts of their sediments, yet studies comparing sediment OC content at regional meadow scales remain sparse. Here, we collected cores from six temperate eelgrass ( Zostera marina ) on the coast British Columbia, Canada, quantify stocks, accumulation rates, sources, examine local drivers variability. Sediment was highly variable—across all sites, top 0–5 cm ranged 83 1089 g m −2 , while 15–20 exhibited a 24‐fold difference, 59 1407 . Carbon rates 4 33 yr −1 Isotopic mixing models revealed that primarily terrestrial (41.3%) canopy‐forming kelps (33.3%), with smaller contribution (25.3%). show variability exceeds meadow‐scale This result likely driven by landscape factors, most notably relative water motion, representing more dominant control seagrass than factors such as canopy complexity. These findings elicit caution when scaling up demonstrate measures hydrodynamic environment could improve estimates soft habitats.

Language: Английский

---