Jeng-Wei Tsai
Keisuke Nakayama- 1Graduate Institute of Bioresources, National Pingtung University of Science and Technology, Pingtung, Taiwan
- 2Graduate School of Engineering, Kobe University, Kobe, Japan
Editorial on the Research Topic
Carbon dynamics in freshwater, coastal and oceanic ecosystems in response to the SDG goals
Introduction
Ocean and coastal areas are buffers against global warming by absorbing 23% CO2 from the atmosphere (Sabine et al., 2004; DeVries et al., 2017). Significantly, coastal and oceanic vegetated ecosystems (such as wetlands, corals, mangroves, seagrass meadows, and kelps), so-called “blue carbon ecosystems” (B.C.E.), have been paid attention to absorb and sequester carbon dioxide from the atmosphere (Nellemann et al., 2009). Recently, freshwater carbon ecosystems, such as lakes, ponds and reservoirs, have also been revealed to contribute to atmospheric carbon sequestration. However, variations in climate patterns, biodiversity spectrums, and anthropogenic activities (e.g., non-sustainable resource extraction, land-based pollution and habitat degradation) across the ecosystems could alter the fragile balance of B.C.E. as carbon sinks or sources (Malhi et al., 2020; Abbass et al., 2022). Also, higher spatiotemporal carbon flux variation was observed in coastal and estuary ecosystems due to intensive anthropogenic activities, natural biological processes, and fluctuating terrestrial loads (Asmala et al., 2016, Asmala et al., 2020). Consequently, understanding the factors and processes that drive the spatiotemporal variations in Dissolved Organic Matter (D.O.M.) quantity and quality under changing environmental conditions would benefit the sustainable use of natural resources in freshwater, coastal and oceanic ecosystems. To contribute to the S.D.G. Goals in Climate Action (Goal 13) and Life Below Water (Goal 14), this Research Topic focuses on carbon dynamics, e.g., GHG emission/storage (blue carbon), as well as environmental stresses such as acidification, fishery resource and pollution (e.g., eutrophication, dead zone and metal pollution) in freshwater, coastal and oceanic ecosystems. Eleven research articles were collected on this Research Topic, as summarized below.
Shallow coastal waters have attracted due to their strong carbon sequestration capacity. Macroalgae culture is considered a natural-based solution for marine carbon sequestration. Research Topics revealed that carbon sequestration by kelp culture is applicable; 5% of DOC released by S. japonica was transformed to refractory DOC, and an estimated 1–2% of the net primary production of cultured kelp was sequestrated as refractory DOC. Also, tidal flats are expected to have the same carbon sequential potential as shallow coastal areas. However, the complicated temporal and spatial variation of carbon dioxide (CO2) makes it difficult to accurately estimate the air-water CO2 fluxes (fCO2). For example, the size of an Submerged Aquatic Vegetation (S.A.V.) patch significantly affects flows and carbon sequestration. In contrast to small-scale phenomena, the higher fCO2 values in the cyclonic and non-eddy regions were revealed due to the upwelling, increasing the surface fCO2. Additionally, physical processes (such as the residence time and water depth) drive CO2 and O2 temporal and spatial patterns; otherwise, biological processes (benthic algae biomass and respiration) may also affect variability within lakes, ponds and reservoirs.
From the water quality perspective, nutrient pollution threatens the seagrass community and may adversely affect their carbon sequestration potential, diminishing the carbon sequestration potential of seagrass ecosystems. Higher nutrient loading elevated labile organic carbon content (e.g., free amino acids and soluble sugars). Contrary, refractory organic carbon compositions of seagrass tissues (i.e., cellulose-associated organic matter) decreased with increasing nutrient loading. Also, an urbanized enclosed bay has environmental problems, such as hypoxia, which degrades carbon dioxide absorption from the atmosphere to the water surface.
As a necessity of new research, the importance of “blue carbon” (marine carbon) in the global quest to achieve carbon neutrality has been well understood. However, freshwater carbon has yet to be considered as a climate change mitigation approach, although freshwater areas (5.0 million km2) are more extensive than coastal areas (1.8 million km2) and are expected to have more significant potential for carbon sequestration. Therefore, we need more investigations on both not only marine carbon but also freshwater carbon. The results of this study provide new and deeper insights into coastal carbon dynamics to propose climate change mitigation in future climate and to achieve the S.D.G.s.
Author contributions
J-WT and KN structured this Research Topic. All guest editors have edited and reviewed the editorial articles, and approved the submitted version.
Funding
This study was supported by National Science and Technology Council, Taiwan, R.O.C. (MOST 111-2313-B-039 -001 -MY3) for J-WT. Also, This study was supported by Japan Society for the Promotion of Science, Japan (18KK0119, 22H01601, 22H05726) for KN.
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
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References
Abbass K., Qasim M. Z., Song H., Murshed M., Mahmood H., Younis I. (2022). A review of the global climate change impacts, adaptation, and sustainable mitigation measures. Environ. Sci. Pollut. Res. 29, 42539–42559. doi: 10.1007/s11356-022-19718-6
Asmala E., Kaartokallio H., Carstensen J., Thomas D. N. (2016). Variation in riverine inputs affect dissolved organic matter characteristics throughout the estuarine gradient. Front. Mar. Sci. 2. doi: 10.3389/fmars.2015.00125
Asmala E., Osburn C. L., Paerl R. W., Paerl H. W. (2020). Elevated organic carbon pulses persist in estuarine environment after major storm events. Limnology Oceanography Lett. 6, 43–50. doi: 10.1002/lol2.10169
DeVries T., Holzer M., Primeau F. (2017). Recent increase in oceanic carbon uptake driven by weaker upper-ocean overturning. Nature 542, 215–218. doi: 10.1038/nature21068
Malhi Y., Janet F., Nathalie S., Martin S., Monica G. T., Christopher B. F., et al. (2020). Climate change and ecosystems: threats, opportunities and solutions. Philos. Trans. R. Soc. B. 375:20190104. doi: 10.1098/rstb.2019.0104
Nellemann C., Corcoran E., Duarte C. M., Valdes L., De Young C., Fonseca L., et al. (2009). Blue carbon. a rapid response assessment (GRID-Arendal, Birkeland Trykkeri AS, Birkeland: United Nations Environmental Programme).
Keywords: dissolved organic matters (DOM), blue carbon, climate change, natural solution, hydrological modeling
Citation: Tsai J-W and Nakayama K (2023) Editorial: Carbon dynamics in freshwater, coastal and oceanic ecosystems in response to the SDG goals. Front. Mar. Sci. 10:1212305. doi: 10.3389/fmars.2023.1212305
Received: 26 April 2023; Accepted: 23 May 2023;
Published: 01 June 2023.
Edited and Reviewed by:
Eric 'Pieter Achterberg, Helmholtz Association of German Research Centres (HZ), GermanyCopyright © 2023 Tsai and Nakayama. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Jeng-Wei Tsai, dHNhaWp3QG1haWwubnB1c3QuZWR1LnR3; Keisuke Nakayama, bmFrYXlhbWFAcGhvZW5peC5rb2JlLXUuYWMuanA=