High variability of Blue Carbon storage in seagrass meadows at the estuary scale

Scientific Reports, Journal Year: 2020, Volume and Issue: 10(1)

Published: April 3, 2020

Seagrass meadows are considered important natural carbon sinks due to their capacity store organic (Corg) in sediments. However, the spatial heterogeneity of storage seagrass sediments needs be better understood improve accuracy Blue Carbon assessments, particularly when strong gradients present. We performed an intensive coring study within a sub-tropical estuary assess variability sedimentary Corg associated with seagrasses, and identify key factors promoting this variability. found pattern estuary, from 52.16 mg cm-3 upper parts, declining 1.06 at mouth, despite general gradient increasing cover habitat extent opposite direction. The underneath came principally allochthonous (non-seagrass) sources (~70-90 %), while contribution seagrasses was low (~10-30 %) throughout entire estuary. Our results showed that stored can highly variable attributed largely accumulation fine inputs sources. Local features existence must estimates coastal ecosystems.

Language: Английский

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Continual migration of patches within a Massachusetts seagrass meadow limits carbon accretion and storage

Communications Earth & Environment, Journal Year: 2025, Volume and Issue: 6(1)

Published: Feb. 20, 2025

Language: Английский

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Seagrass losses since mid‐20th century fuelled CO₂ emissions from soil carbon stocks

Global Change Biology, Journal Year: 2020, Volume and Issue: 26(9), P. 4772 - 4784

Published: July 7, 2020

Abstract Seagrass meadows store globally significant organic carbon (C org ) stocks which, if disturbed, can lead to CO 2 emissions, contributing climate change. Eutrophication and thermal stress continue be a major cause of seagrass decline worldwide, but the associated emissions remain poorly understood. This study presents comprehensive estimates soil C erosion following eutrophication‐driven loss in Cockburn Sound (23 km between 1960s 1990s) identifies main drivers. We estimate that shallow (<5 m depth) had significantly higher 50 cm thick soils (4.5 ± 0.7 kg /m than previously vegetated counterparts (0.5 0.1 ). In deeper areas (>5 m), however, bare were not different (2.6 0.3 3.0 0.6 , respectively). The sequestration capacity prevailed deep (55 11 21 7 g −2 year −1 respectively), was lost areas. identified canopy alone does necessarily drive changes but, when combined with high hydrodynamic energy, occurred. Our point at ~0.20 m/s as critical shear velocity threshold causing erosion. estimate, from field studies satellite imagery, (within top cm) likely resulted cumulative 0.06–0.14 Tg 2‐eq over last 40 years Sound. estimated indirect impacts (i.e. eutrophication, light stress) ~161,150 ha seagrasses Australia, release 11–21 ‐eq since 1950s, increasing land‐use change Australia by 1.1%–2.3% per annum. patterns described serve baseline potential disturbance meadows.

Language: Английский

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A Synthesis of Blue Carbon Stocks, Sources, and Accumulation Rates in Eelgrass (Zostera marina) Meadows in the Northeast Pacific

Global Biogeochemical Cycles, Journal Year: 2020, Volume and Issue: 34(2)

Published: Jan. 6, 2020

Abstract There is increasing urgency to implement climate change mitigation strategies that enhance greenhouse gas removal from the atmosphere and reduce carbon dioxide (CO 2 ) emissions. Recently, coastal “blue carbon” habitats⁠—mangroves, salt marshes, seagrass meadows—have received attention for their ability capture CO store organic (OC), primarily in sediments. Across habitat types regions, however, information about sequestration rates sources of local sediments remains sparse. Here we compiled recently obtained estimates sediment OC stocks 139 cores collected temperate ( Zostera marina meadows Alaska, British Columbia, Washington, Oregon. all content averaged 0.75%. Organic top 25 cm 1 m 1,846 7,168 g −2 , respectively. Carbon ranged 4.6 93.0 yr −1 24.8 . Isotopic data this region suggest largely noneelgrass sources. In general, these values are comparable those other Z. meadows, but significantly lower than previously reported seagrasses globally. These results further highlight need species‐level quantification blue parameters. While eelgrass may not sequester as much elsewhere, policy incentives should still be implemented protect existing critical ecosystem services associated with habitats.

Language: Английский

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Carbon and Nitrogen Stocks and Burial Rates in Intertidal Vegetated Habitats of a Mesotidal Coastal Lagoon

Ecosystems, Journal Year: 2021, Volume and Issue: 25(2), P. 372 - 386

Published: June 22, 2021

Language: Английский

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Major impacts and societal costs of seagrass loss on sediment carbon and nitrogen stocks

Ecosphere, Journal Year: 2021, Volume and Issue: 12(7)

Published: July 1, 2021

Abstract Seagrass meadows constitute important carbon sinks, and the ongoing global loss of seagrass habitats raises concerns about release stored in their sediments. However, actual consequences for nutrients remain unclear. Here, we take advantage well‐documented historic losses eelgrass ( Zostera marina ) along Swedish NW coast to assess how contents organic (C) nitrogen (N) sediment change when a meadow is lost. We find unusually high C N (on average 3.7% 0.39% DW, respectively) sediments down >100 cm depth, suggesting that these hot spots storage. stocks were strongly influenced by wave exposure almost twice as sheltered compared exposed meadows. The composition stable isotope values distinctly different areas have lost meadows, with on >2.6 times lower N. results indicate an erosion >35 following historical loss, more vulnerable stocks. suggest has resulted 60.2 Mg 6.63 per hectare, estimated economic cost society 7944 141,355 US$/ha, respectively. value storage represents one highest monetary presented ecosystem service provided seagrasses shows are particularly mitigating eutrophication. Following documented approximately 10 km 2 study area, it over 60,000 was released coastal environment 20‐yr period, which constitutes three annual river load coast. exemplifies significant role sinks both nutrients, risk nutrient vegetation should be taken into account spatial management other habitats.

Language: Английский

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Loss of POC and DOC on seagrass sediments by hydrodynamics

The Science of The Total Environment, Journal Year: 2023, Volume and Issue: 901, P. 165976 - 165976

Published: Aug. 1, 2023

Coastal development and climate change are sparking growing concern about the vulnerability of organic carbon (OC) stocks in marine sediments to remineralization, especially high threaten coastal ecosystems like seagrass meadows. Uncertainties still exist regarding role played by hydrodynamics, canopies sediment properties OC resuspension remineralization. A set laboratory experiments were conducted assess, for first time, mechanisms which particulate dissolved (POC DOC) may be released remineralized under hydrodynamic conditions (i.e., unidirectional oscillatory flows) two eelgrass densities grain size content). After a gradually increase forces, our results demonstrated that presence reduced erosion loss high-density canopies, while low-density promote (on average, 1.8-fold higher than canopies). We also flows similar DOC from surface 15.5 ± 1.4 18.4 1.8 g m-2, respectively), whereas flow significantly more POC (from 10.8 1.1 32.1 5.6 m-2 flows, respectively). was strongly influenced both meadow structure lower density shoot area) mud water found that, although >74 % upper within 30 days, relatively amount is recalcitrant, highlighting its potential formation blue deposits. This study highlights deposits if degraded and/or yield stronger storms, could potentially weaken meadows' service as ecosystem future.

Language: Английский

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Dynamics and fate of blue carbon in a mangrove–seagrass seascape: influence of landscape configuration and land-use change

Landscape Ecology, Journal Year: 2021, Volume and Issue: 36(5), P. 1489 - 1509

Published: March 1, 2021

Abstract Context Seagrass meadows act as efficient natural carbon sinks by sequestering atmospheric CO 2 and through trapping of allochthonous organic material, thereby preserving (C org ) in their sediments. Less understood is the influence landscape configuration transformation (land-use change) on sequestration dynamics coastal seascapes across land–sea interface. Objectives We explored degradation adjacent mangroves fate C seagrass habitats. Methods Through predictive modelling, we assessed sedimentary content, stocks source composition multiple (km-wide buffer zones) dominated different communities northwest Madagascar. The study area encompassed to intact deforested mangroves. Results content was influenced a combination metrics inherent habitat plant- sediment-properties. found strong land-to-sea gradient, likely driven hydrodynamic forces, generating distinct patterns levels seascapes. There higher mangrove signal surface sediments closer area, possibly due an escalated export from soils. Seascapes comprising large continuous had comparison more diverse patchy Conclusion Our results emphasize benefit consider seascape connectivity accurately assess Understanding spatial variability what driving observed useful for identifying sink hotspots develop management prioritizations.

Language: Английский

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Evolution of flow velocity from the leading edge of 2-D and 3-D submerged canopies

Journal of Fluid Mechanics, Journal Year: 2021, Volume and Issue: 916

Published: April 14, 2021

Abstract

Language: Английский

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First assessment of seagrass carbon accumulation rates in Sweden: A field study from a fjord system at the Skagerrak coast

PLOS Climate, Journal Year: 2023, Volume and Issue: 2(1), P. e0000099 - e0000099

Published: Jan. 5, 2023

Seagrass meadows are globally important blue carbon sinks. In northern cold-temperate regions, eelgrass ( Zostera marina ) is the dominant seagrass species, and although their sedimentary stocks have been quantified across information regarding CO 2 withdrawal capacity as sinks remains scarce. Here we assessed (C org accumulation rates (CARs) well organic matter sources in five Gullmar Fjord area on Swedish Skagerrak coast. We found that mean (±SD) CAR was 14 ± 3 g C m -2 yr -1 over last ~120–140 years (corresponding to a yearly uptake of 52.4 12.6 CO2 ). The sink line with other Z . areas but relatively low compared species regions globally. About half (7.1 3.3 originated from macroalgae biomass, which highlights importance non-seagrass derived material for function area. were similar among sites when comparing at standardized depth 50 cm (4.6–5.9 kg ), showed large variation total extent cores (ranging 0.7 20.6 sediment depths 11 least 149 cm). accretion (1.18–1.86 mm thick deposits (with maximum >150 depth) suggests likely accumulated an extended period time, documented loss region associated erosion could potentially offset centuries sequestration.

Language: Английский

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