Carbon stocks and accumulation rates in Red Sea seagrass meadows

Abstract Increasing the protection of coastal vegetated ecosystems has been suggested as one strategy to compensate for increasing carbon dioxide (CO2) in the atmosphere as the capacity of these habitats to sequester and store carbon exceeds that of terrestrial habitats. Seagrasses are a group of foundation species that grow in shallow coastal and estuarine systems and have an exceptional ability to sequester and store large quantities of carbon in biomass and, particularly, in sediments. However, carbon stocks (Corg stocks) and carbon accumulation rates (Corg accumulation) in seagrass meadows are highly variable both spatially and temporally, making it difficult to extrapolate this strategy to areas where information is lacking. In this study, Corg stocks and Corg accumulation were determined at 11 eelgrass meadows across New England, representing a range of eutrophication and exposure conditions. In addition, the environmental factors and structural characteristics of meadows related to variation in Corg stocks were identified. The objectives were accomplished by assessing stable isotopes of δ13C and δ15N as well as %C and %N in plant tissues and sediments, measuring grain size and 210Pb of sediment cores, and through assessing site exposure. Variability in Corg stocks in seagrass meadows is well predicted using commonly measured environmental variables such as grain size distribution. This study allows incorporation of data and insights for the northwest Atlantic, where few studies on carbon sequestration by seagrasses have been conducted.

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The sediment carbon stocks of intertidal seagrass meadows in Scotland

Estuarine Coastal and Shelf Science ◽

10.1016/j.ecss.2021.107442 ◽

2021 ◽

pp. 107442

Author(s):

Maria Potouroglou ◽

Danielle Whitlock ◽

Luna Milatovic ◽

Gillian MacKinnon ◽

Hilary Kennedy ◽

...

Keyword(s):

Carbon Stocks ◽

Seagrass Meadows ◽

Intertidal Seagrass ◽

Sediment Carbon

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Investing in Blue Natural Capital to Secure a Future for the Red Sea Ecosystems

Frontiers in Marine Science ◽

10.3389/fmars.2020.603722 ◽

2021 ◽

Vol 7 ◽

Author(s):

Maha J. Cziesielski ◽

Carlos M. Duarte ◽

Nojood Aalismail ◽

Yousef Al-Hafedh ◽

Andrea Anton ◽

...

Keyword(s):

Sustainable Development ◽

Red Sea ◽

Natural Capital ◽

Economic Benefits ◽

Environmental Conservation ◽

Coastal Development ◽

Population Pressure ◽

Economic Losses ◽

Seagrass Meadows ◽

Marine Habitats

For millennia, coastal and marine ecosystems have adapted and flourished in the Red Sea’s unique environment. Surrounded by deserts on all sides, the Red Sea is subjected to high dust inputs and receives very little freshwater input, and so harbors a high salinity. Coral reefs, seagrass meadows, and mangroves flourish in this environment and provide socio-economic and environmental benefits to the bordering coastlines and countries. Interestingly, while coral reef ecosystems are currently experiencing rapid decline on a global scale, those in the Red Sea appear to be in relatively better shape. That said, they are certainly not immune to the stressors that cause degradation, such as increasing ocean temperature, acidification and pollution. In many regions, ecosystems are already severely deteriorating and are further threatened by increasing population pressure and large coastal development projects. Degradation of these marine habitats will lead to environmental costs, as well as significant economic losses. Therefore, it will result in a missed opportunity for the bordering countries to develop a sustainable blue economy and integrate innovative nature-based solutions. Recognizing that securing the Red Sea ecosystems’ future must occur in synergy with continued social and economic growth, we developed an action plan for the conservation, restoration, and growth of marine environments of the Red Sea. We then investigated the level of resources for financial and economic investment that may incentivize these activities. This study presents a set of commercially viable financial investment strategies, ecological innovations, and sustainable development opportunities, which can, if implemented strategically, help ensure long-term economic benefits while promoting environmental conservation. We make a case for investing in blue natural capital and propose a strategic development model that relies on maintaining the health of natural ecosystems to safeguard the Red Sea’s sustainable development.

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Geochemistry, sulfur isotope composition, and accumulation rates of Red Sea geothermal deposits

Economic Geology ◽

10.2113/gsecongeo.75.3.445 ◽

1980 ◽

Vol 75 (3) ◽

pp. 445-459 ◽

Cited By ~ 64

Author(s):

W. C. Shanks ◽

J. L. Bischoff

Keyword(s):

Red Sea ◽

Sulfur Isotope ◽

Isotope Composition ◽

Accumulation Rates ◽

Sulfur Isotope Composition

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Holocene Carbon Stocks and Carbon Accumulation Rates Altered in Soils Undergoing Permafrost Thaw

Ecosystems ◽

10.1007/s10021-011-9500-4 ◽

2011 ◽

Vol 15 (1) ◽

pp. 162-173 ◽

Cited By ~ 57

Author(s):

Caitlin E. Hicks Pries ◽

Edward A. G. Schuur ◽

K. Grace Crummer

Keyword(s):

Carbon Stocks ◽

Carbon Accumulation ◽

Accumulation Rates ◽

Permafrost Thaw ◽

Carbon Accumulation Rates

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Organic carbon in surface sediments of the North Sea and Skagerrak

10.5194/bg-2020-352 ◽

2020 ◽

Author(s):

Markus Diesing ◽

Terje Thorsnes ◽

Lilja Rún Bjarnadóttir

Keyword(s):

Organic Carbon ◽

North Sea ◽

Carbon Stocks ◽

Carbon Accumulation ◽

Complex Nature ◽

Accumulation Rates ◽

The North ◽

Continental Shelves ◽

Shelf Sediments ◽

The North Sea

Abstract. Continental shelf sediments are places of both rapid organic carbon turnover and accumulation, while at the same time increasingly subjected to human-induced disturbances. Recent research suggests that shelf sediments might have a role to play as a natural climate solution, e.g. by protecting the seafloor against human-induced disturbance. However, we have an incomplete understanding about the centres of organic carbon accumulation and storage on continental shelves. To better constrain the rate of accumulation and the mass of organic carbon that is stored in sediments, we developed and applied a spatial modelling framework that allows to estimate those quantities from sparse observations and predictor variables known or suspected to influence the spatial patterns of these parameters. This paper presents spatial distribution patterns of organic carbon densities and accumulation rates in the North Sea and Skagerrak. We found that organic carbon stocks and accumulation rates are highest in the Norwegian Trough, while large parts of the North Sea are characterised by low stocks and zero net-accumulation. The total stock of organic carbon that is stored in the upper 0.1 m of sediments amounted to 230.5 ± 134.5 Tg, of which approximately 26 % are stored in the Norwegian Trough. Rates of organic carbon accumulation in the Norwegian Trough are on par with those reported from nearby fjords. We provide baseline datasets that could be used in marine management, e.g. for the establishment of carbon protection zones. Additionally, we highlight the complex nature of continental shelves with zones of rapid carbon cycling and accumulation juxtaposed, which will require further detailed and spatially explicit analyses to constrain sedimentary organic carbon stocks and accumulation rates globally.

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Carbon Stocks and Accumulation Rates in Salt Marshes of the Pacific Coast of Canada

10.5194/bg-2018-166 ◽

2018 ◽

Cited By ~ 1

Author(s):

Stephen G. Chastain ◽

Karen Kohfeld ◽

Marlow G. Pellatt

Keyword(s):

Salt Marsh ◽

Salt Marshes ◽

Pacific Coast ◽

Carbon Stocks ◽

Carbon Accumulation ◽

Climate Mitigation ◽

Accumulation Rates ◽

The Pacific ◽

Clayoquot Sound ◽

Carbon Accumulation Rates

Abstract. Tidal salt marshes are known to accumulate blue carbon at high rates relative to their surface area and have been put forth as a potential means for enhanced CO2 sequestration. However, estimates of salt marsh carbon accumulation rates are based on a limited number of marshes globally and the estimation of carbon accumulation rates require detailed dating to provide accurate estimates. We address one data gap along the Pacific Coast of Canada by estimating carbon stocks in 34 sediment cores and estimating carbon accumulation rates using 210Pb dating on four cores from seven salt marshes within the Clayoquot Sound UNESCO Biosphere Reserve and Pacific Rim National Park Reserve of Canada (49.2° N, 125.80° W). Carbon stocks averaged 80.6 ± 43.8 megagrams of carbon per hectare (Mg C ha−1) between the seven salt marshes, and carbon accumulation rates averaged 146 ± 102 grams carbon per square meter per year (g C m−2 yr−1). These rates are comparable to those found in salt marshes further south along the Pacific coast of North America (32.5–38.2° N) and at similar latitudes in Eastern Canada and Northern Europe (43.6–55.5° N). The seven Clayoquot Sound salt marshes currently accumulate carbon at a rate of 54.28 Mg C yr−1 over an area of 46.94 ha, 87 % of which occurs in the high marsh zone. On a per-hectare basis, Clayoquot Sound salt marsh soils accumulate carbon at least one order of magnitude more quickly than the average of global boreal forest soils, and approximately two times larger than rates for forests in British Columbia. However, because of their relatively small area, we suggest that their carbon accumulation rate capacity could best be considered as a climate mitigation co-benefit when conserving for other salt marsh ecosystem services.

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Anomalies in the Carbonate System of Red Sea Coastal Habitats

10.5194/bg-2019-200 ◽

2019 ◽

Author(s):

Kimberlee Baldry ◽

Vincent Saderne ◽

Daniel C. McCorkle ◽

James H. Churchill ◽

Susana Agusti ◽

...

Keyword(s):

Red Sea ◽

Dissolved Inorganic Carbon ◽

Total Alkalinity ◽

Carbonate Precipitation ◽

Mangrove Forests ◽

Sedimentary Processes ◽

Carbonate System ◽

Seagrass Meadows ◽

Basin Scale ◽

The Impact

Abstract. We use observations of dissolved inorganic carbon (DIC) and total alkalinity (TA) to assess the impact of ecosystem metabolic processes on coastal waters of the eastern Red Sea. A simple, single-end-member mixing model is used to account for the influence of mixing with offshore waters and evaporation/precipitation, and to model ecosystem-driven perturbations on the carbonate system chemistry of coral reefs, seagrass meadows and mangrove forests. We find that (1) along-shelf changes in TA and DIC exhibit strong linear trends that are consistent with basin-scale net calcium carbonate precipitation; (2) ecosystem-driven changes in TA and DIC are larger than offshore variations in > 85 % of sampled seagrass meadows and mangrove forests, changes which are influenced by a combination of longer water residence times and community metabolic rates; and (3) the sampled mangrove forests show strong and consistent contributions from both organic respiration and other sedimentary processes (carbonate dissolution and secondary redox processes), while seagrass meadows display more variability in the relative contributions of photosynthesis and other sedimentary processes (carbonate precipitation and oxidative processes).

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Warming enhances carbon dioxide and methane fluxes from Red Sea seagrass (<i>Halophila stipulacea</i>) sediments

10.5194/bg-2019-93 ◽

2019 ◽

Author(s):

Celina Burkholz ◽

Neus Garcias-Bonet ◽

Carlos M. Duarte

Keyword(s):

Carbon Dioxide ◽

Red Sea ◽

Seawater Temperature ◽

Isotopic Signature ◽

Feedback Mechanism ◽

Maximum Temperature ◽

Co2 Fluxes ◽

Seagrass Meadows ◽

Halophila Stipulacea ◽

Carbon Dioxide Co2

Abstract. Seagrass meadows are autotrophic ecosystems storing carbon in their biomass and sediments, but they have also been shown to be sources of carbon dioxide (CO2) and methane (CH4). Seagrasses can be negatively affected by increasing seawater temperatures, but the effects of warming on CO2 and CH4 fluxes in seagrass meadows have not yet been reported. Here, we examine the effect of two disturbances on air-seawater fluxes of CO2 and CH4 in Red Sea Halophila stipulacea communities compared to adjacent unvegetated sediments using cavity ring-down spectroscopy. We first characterized CO2 and CH4 fluxes in vegetated and adjacent unvegetated sediments, and then experimentally examined their response, along with that of the C isotopic signature of CO2 and CH4, to gradual warming from 25 °C (winter seawater temperature) to 37 °C, 2 °C above current maximum temperature. In addition, we assessed the response to prolonged darkness, thereby providing insights into the possible role of suppressing plant photosynthesis in supporting CO2 and CH4 fluxes. We detected distinct differences between vegetated and unvegetated sediments, with the vegetated sediments supporting 6-fold higher CO2 fluxes, and 10- to 100-fold higher CH4 fluxes. Warming led to an increase in net CO2 and CH4 fluxes, reaching average fluxes of 10,422.18 ± 2,570.12 µmol CO2 m−2 d−1 and 88.11 ± 15.19 µmol CH4 m−2 d−1, while CO2 and CH4 fluxes decreased over time in sediments maintained at 25 °C. Prolonged darkness led to an increase in CO2 fluxes but a decrease in CH4 fluxes in vegetated sediments. These results add to previous research identifying Red Sea seagrass meadows as a significant source of CH4, while also indicating that sublethal warming may lead to increased emissions of greenhouse gases from seagrass meadows, providing a feedback mechanism that may contribute to further enhance global warming.

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Invasion of an invader: a case study from the Suez Channel

10.7287/peerj.preprints.1014v1 ◽

2015 ◽

Author(s):

Yasser Geneid ◽

Amgad El Shaffai

Keyword(s):

Invasive Species ◽

Red Sea ◽

Water Discharge ◽

Algal Species ◽

Suez Canal ◽

Current Status ◽

Fishing Ground ◽

Western Coast ◽

Seagrass Meadows ◽

The Mediterranean

After the year 1869, a major change in the Mediterranean marine ecosystem occurred. A pathway called Suez Canal was created allowing the passage of alien invasive species from the Red Sea to the Mediterranean, which is currently harboring over 900 introduced marine species. About 54% of these established non-native species reached through the Suez Canal. Whilst most of the studies dealing with marine invasive species focused on the Mediterranean, very few were done in the Suez Canal itself. The goal of this study is to review the distribution and current status of two invasive marine plants in the Suez Canal, specifically the Bitter Lakes area. This area was selected because of its special environmental conditions and its importance as a major fishing ground in the entire canal. Visual observations of the marine vegetation in the study sites were carried out starting year 2001. Halophila stipulacea , a tropical seagrass distributed along the coasts of the western Indian Ocean and the Red Sea, has migrated and is widely found around the Mediterranean. It was recorded in the Suez Canal by the Cambridge Expedition in 1924 and is known to occur in the shallow sandy-muddy bottom areas along its western coast. Since 2000, different studies along the Bitter Lakes have shown total disappearance of seagrass meadows caused by another invader that have replaced the seagrass plants and reached a percentage cover of nearly 100% in some of the studied sites. A new intruder was the green seaweed Caulerpa prolifera, a Mediterranean algal species that was recorded in the Gulf of Suez in 1984, among few species migrated from the Mediterranean to the Red Sea. It has rapidly colonized different locations in the Suez Canal replacing H. stipulacea meadows. However, in 2004, a dramatic change took place in the study area where C. prolifera began diminishing allowing the previously found H. stipulacea to inhabit the seafloor. While salinity reduction from hypersaline conditions – due to growing of coastal communities along the Bitter Lakes with more fresh water discharge – may cause the expansion of C. prolifera in the study area, the reasons why it declined and disappeared are still unclear.

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