Carbon sequestration in aquatic ecosystems: Recent advances and challenges

Santos, Isaac R.; Hatje, Vanessa; Serrano, Óscar; Bastviken, David; Krause‐Jensen, Dorte

doi:10.1002/lno.12268

Cited by 5 publications

(3 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Dissolved inorganic carbon (DIC) used for autochthonous primary production can be from t-OM decomposition—an inorganic carbon pathway of terrestrial subsidy that has been largely overlooked (Lennon et al 2006; Demars et al 2020). Such a neglect may be partly due to the assumption that primary producers use DIC mainly from atmospheric carbon dioxide (CO 2 ), but accumulating studies show that most freshwater ecosystems are net carbon sources (Santos et al 2022).…”

Section: Introductionmentioning

confidence: 99%

Terrestrial Support of Aquatic Food Webs via an Overlooked Pathway—Inorganic Carbon and its Significance to Global Carbon Cycle

Wang

Durand

Lawler

et al. 2023

Preprint

View full text Add to dashboard Cite

Freshwater ecosystems receive substantial terrestrial organic matter (t-OM) from surrounding landscapes. How the t-OM is transferred affects aquatic food webs and global carbon budgets. Previous studies have emphasized terrestrial support of aquatic ecosystems via direct organic carbon subsidy, overlooking the dissolved inorganic carbon (DIC) pathway, that is, DIC from t-OM decomposition is used by aquatic primary producers, supporting higher trophic levels. Using 2-year13C and15N measurements of phytoplankton, zooplankton, terrestrial plants, sediments, dissolved and particulate organic matter from seasonal wetlands, we found that while zooplankton (mid-trophic consumers) used t-OM directly in January, in March and May zooplankton were mainly supported by phytoplankton that used DIC recycled from t-OM mineralization and methanogenesis. The dominance of this DIC pathway is tightly coupled with the characteristics of these systems. Mineralization and methanogenesis of rich fresh t-OM resulted in supersaturated CO2 with high CO2 and CH4 emissions. Atmospheric CO2 diffusion and methanogenesis significantly enriched δ13C of DIC, leading to wide variations in δ13C of DIC between -12.4 and 6.7 ‰, which provided ideal conditions to quantify carbon cycling in these widespread but understudied ecosystems. Our findings draw attention to potentially high carbon emissions from temporary freshwater ecosystems that are being increasingly common under warming climate.

show abstract

Section: Introductionmentioning

confidence: 99%

Terrestrial Support of Aquatic Food Webs via an Overlooked Pathway—Inorganic Carbon and its Significance to Global Carbon Cycle

Wang

Durand

Lawler

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…20% of the global primary production on Earth (Gattuso et al, 1998). In temperate regions, this is largely due both to massive phytoplankton blooms and dense colonisation by macroalgae that mostly store carbon in the form of glycans, contributing substantially to local and global carbon sequestration (Santos et al, 2022). Microbial breakdown represents a crucial bottleneck to re‐inject the large pool of algal organic matter in the marine carbon cycle (Buchan et al, 2014), by (i) making it accessible for higher trophic levels, (ii) liberating dissolved or particulate matter for local recycling or further export, (iii) remineralizing it back to atmospheric CO 2 and (iv) eventually influencing how much carbon is sequestered.…”

Section: Introductionmentioning

confidence: 99%

Seasonal dynamics of a glycan‐degrading flavobacterial genus in a tidally mixed coastal temperate habitat

Brunet,

Le Duff,

Rigaut‐Jalabert

et al. 2023

Environmental Microbiology

View full text Add to dashboard Cite

Coastal marine habitats constitute hotspots of primary productivity. In temperate regions, this is due both to massive phytoplankton blooms and dense colonisation by macroalgae that mostly store carbon as glycans, contributing substantially to local and global carbon sequestration. Because they control carbon and energy fluxes, algae‐degrading microorganisms are crucial for coastal ecosystem functions. Environmental surveys revealed consistent seasonal dynamics of alga‐associated bacterial assemblages, yet resolving what factors regulate the in situ abundance, growth rate and ecological functions of individual taxa remains a challenge. Here, we specifically investigated the seasonal dynamics of abundance and activity for a well‐known alga‐degrading marine flavobacterial genus in a tidally mixed coastal habitat of the Western English Channel. We show that members of the genus Zobellia are a stable, low‐abundance component of healthy macroalgal microbiota and can also colonise particles in the water column. This genus undergoes recurring seasonal variations with higher abundances in winter, significantly associated to biotic and abiotic variables. Zobellia can become a dominant part of bacterial communities on decaying macroalgae, showing a strong activity and high estimated in situ growth rates. These results provide insights into the seasonal dynamics and environmental constraints driving natural populations of alga‐degrading bacteria that influence coastal carbon cycling.

show abstract

“…CO 2 enters the ocean via physical, chemical, and biological pathways where it is stored in biomass and sediments, or remineralized to re-enter the atmosphere. The term Blue Carbon refers to the carbon sequestered in the ocean and is usually associated with vegetated coastal ecosystems (Santos et al, 2022).…”

Section: Introductionmentioning

confidence: 99%

Small carbon stocks in sediments of Baltic Sea eelgrass meadows

Billman,

Santos,

Jahnke

2023

Front. Mar. Sci.

Self Cite

View full text Add to dashboard Cite

Seagrass meadows act as an effective carbon sink and store carbon in the sediments for substantial periods of time. The drivers of carbon sequestration are complex, and global and regional estimates of carbon stocks have large uncertainties. Here, we report new carbon stock estimates from 14 sites along the Swedish coast and compile existing literature to estimate the magnitude of carbon stocks of Zostera marina (eelgrass) meadows in the Baltic Sea. Eelgrass meadows in the Baltic Sea have considerably lower carbon content and lower stocks (0.25 ± 0.21% DW, 635 ± 321 g C m-2) than in the Kattegat-Skagerrak region (3.25 ± 2.78% DW, 3457 ± 3382 g C m-2) and the average for temperate regions in general (1.4 ± 0.4% DW, 2721 ± 989 g C m-2). Unfavorable growing conditions for eelgrass in the Baltic Sea often lead to meadows occurring in areas of high hydrodynamics, preventing significant carbon accumulation. Stable isotopes revealed that the dominating source of organic carbon in the meadows was planktonic, further highlighting that Baltic Sea eelgrass meadows are not major carbon reservoirs in comparison to unvegetated sediments and other seagrass areas. The results also highlight that environmental conditions drive intraspecific variation of carbon sequestration on large spatial scales. Overall, the carbon stocks and sequestration potential in eelgrass meadows of the Baltic Sea are small compared to other temperate regions.

show abstract

Carbon sequestration in aquatic ecosystems: Recent advances and challenges

Cited by 5 publications

References 28 publications

Terrestrial Support of Aquatic Food Webs via an Overlooked Pathway—Inorganic Carbon and its Significance to Global Carbon Cycle

Terrestrial Support of Aquatic Food Webs via an Overlooked Pathway—Inorganic Carbon and its Significance to Global Carbon Cycle

Seasonal dynamics of a glycan‐degrading flavobacterial genus in a tidally mixed coastal temperate habitat

Small carbon stocks in sediments of Baltic Sea eelgrass meadows

Contact Info

Product

Resources

About