Challenges to select suitable habitats and demonstrate ‘additionality’ in Blue Carbon projects: A seagrass case study

Lafratta, Anna; Serrano, Óscar; Masqué, Pere; Fernandes, Milena; Gaylard, Sam; Lavery, Paul

doi:10.1016/j.ocecoaman.2020.105295

Cited by 15 publications

(13 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Further studies (e.g. deployment of surface elevation tables to measure sediment accretion in situ) are required to overcome the limitations of radioisotopes 40 . Overall, the high seagrass primary production together with the rapid accumulation of suspended particles results in highly depositional environments that enhance carbon accumulation and preservation, which could explain the relatively high C org storage capacity of seagrass meadows along the Colombian Caribbean compared to other meadows globally.…”

Section: Discussionmentioning

confidence: 99%

“…It is important to note that these estimates are likely underestimating seagrass soil C org storage in the Colombian Caribbean, owing to poor seagrass mapping in some regions and the exclusion of meadows formed by small species meadows of the genera Syringodium , Halophila , Halodule and Ruppia that occur in Colombia. However, owing to the lack of excess 210 Pb in some meadows, further studies are required to determine whether some of the meadows studied continue to accumulate soil C org 40 . Indeed, carbonate burial in seagrass meadows, which is particularly important in tropical regions, likely offsets a portion of the CO 2 sequestered through the burial of C org 53 .…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Seagrass blue carbon stocks and sequestration rates in the Colombian Caribbean

Serrano

Gómez-López

Sánchez-Valencia

et al. 2021

Sci Rep

View full text Add to dashboard Cite

Seagrass ecosystems rank amongst the most efficient natural carbon sinks on earth, sequestering CO2 through photosynthesis and storing organic carbon (Corg) underneath their soils for millennia and thereby, mitigating climate change. However, estimates of Corg stocks and accumulation rates in seagrass meadows (blue carbon) are restricted to few regions, and further information on spatial variability is required to derive robust global estimates. Here we studied soil Corg stocks and accumulation rates in seagrass meadows across the Colombian Caribbean. We estimated that Thalassia testudinum meadows store 241 ± 118 Mg Corg ha−1 (mean ± SD) in the top 1 m-thick soils, accumulated at rates of 122 ± 62 and 15 ± 7 g Corg m−2 year−1 over the last ~ 70 years and up to 2000 years, respectively. The tropical climate of the Caribbean Sea and associated sediment run-off, together with the relatively high primary production of T. testudinum, influencing biotic and abiotic drivers of Corg storage linked to seagrass and soil respiration rates, explains their relatively high Corg stocks and accumulation rates when compared to other meadows globally. Differences in soil Corg storage among Colombian Caribbean regions are largely linked to differences in the relative contribution of Corg sources to the soil Corg pool (seagrass, algae Halimeda tuna, mangrove and seston) and the content of soil particles < 0.016 mm binding Corg and enhancing its preservation. Despite the moderate areal extent of T. testudinum in the Colombian Caribbean (661 km2), it sequesters around 0.3 Tg CO2 year−1, which is equivalent to ~ 0.4% of CO2 emissions from fossil fuels in Colombia. This study adds data from a new region to a growing dataset on seagrass blue carbon and further explores differences in meadow Corg storage based on biotic and abiotic environmental factors, while providing the basis for the implementation of seagrass blue carbon strategies in Colombia.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Seagrass blue carbon stocks and sequestration rates in the Colombian Caribbean

Serrano

Gómez-López

Sánchez-Valencia

et al. 2021

Sci Rep

View full text Add to dashboard Cite

show abstract

“…Seagrass restoration has been suggested as a Blue Carbon strategy for climate change mitigation. The effectiveness of this strategy remains to be demonstrated [288]. Considering the huge cost of transplants, it is also necessary to question the cost-benefit ratio compared to the strategy of reducing carbon emissions.…”

mentioning

confidence: 99%

Restoration of Seagrass Meadows in the Mediterranean Sea: A Critical Review of Effectiveness and Ethical Issues

Boudouresque

Blanfuné

Pergent

et al. 2021

Water

View full text Add to dashboard Cite

Some species of seagrasses (e.g., Zostera marina and Posidonia oceanica) have declined in the Mediterranean, at least locally. Others are progressing, helped by sea warming, such as Cymodocea nodosa and the non-native Halophila stipulacea. The decline of one seagrass can favor another seagrass. All in all, the decline of seagrasses could be less extensive and less general than claimed by some authors. Natural recolonization (cuttings and seedlings) has been more rapid and more widespread than was thought in the 20th century; however, it is sometimes insufficient, which justifies transplanting operations. Many techniques have been proposed to restore Mediterranean seagrass meadows. However, setting aside the short-term failure or half-success of experimental operations, long-term monitoring has usually been lacking, suggesting that possible failures were considered not worthy of a scientific paper. Many transplanting operations (e.g., P. oceanica) have been carried out at sites where the species had never previously been present. Replacing the natural ecosystem (e.g., sandy bottoms, sublittoral reefs) with P. oceanica is obviously inappropriate in most cases. This presupposes ignorance of the fact that the diversity of ecosystems is one of the bases of the biodiversity concept. In order to prevent the possibility of seagrass transplanting from being misused as a pretext for further destruction, a guide for the proper conduct of transplanting is proposed.

show abstract

“…greater loss in the center of a patch during a marine heat wave; Aoki et al 2021), or the losses may be widespread. Lafratta et al (2020) reported that 75%-90% of stored organic carbon was remineralized in the top meter in Australian Posidonia meadows following their loss and partial restoration. A shading experiment in the Gulf of Mexico that induced a small-scale die off resulted in a 50%-65% loss of organic matter in the top 8 cm of sediment, including 50% lost from the top 1 cm (Trevathan-Tackett et al 2017).…”

Section: Global Estimates and Regional Case Studies Of Carbon Stockmentioning

confidence: 99%

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

Johannessen

2022

Environ. Res. Lett.

View full text Add to dashboard Cite

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

show abstract

Challenges to select suitable habitats and demonstrate ‘additionality’ in Blue Carbon projects: A seagrass case study

Cited by 15 publications

References 37 publications

Seagrass blue carbon stocks and sequestration rates in the Colombian Caribbean

Seagrass blue carbon stocks and sequestration rates in the Colombian Caribbean

Restoration of Seagrass Meadows in the Mediterranean Sea: A Critical Review of Effectiveness and Ethical Issues

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

Contact Info

Product

Resources

About