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Pessarrodona A, Franco-Santos RM, Wright LS, Vanderklift MA, Howard J, Pidgeon E, Wernberg T, Filbee-Dexter K. Carbon sequestration and climate change mitigation using macroalgae: a state of knowledge review. Biol Rev Camb Philos Soc 2023; 98:1945-1971. [PMID: 37437379 DOI: 10.1111/brv.12990] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 06/05/2023] [Accepted: 06/07/2023] [Indexed: 07/14/2023]
Abstract
The conservation, restoration, and improved management of terrestrial forests significantly contributes to mitigate climate change and its impacts, as well as providing numerous co-benefits. The pressing need to reduce emissions and increase carbon removal from the atmosphere is now also leading to the development of natural climate solutions in the ocean. Interest in the carbon sequestration potential of underwater macroalgal forests is growing rapidly among policy, conservation, and corporate sectors. Yet, our understanding of whether carbon sequestration from macroalgal forests can lead to tangible climate change mitigation remains severely limited, hampering their inclusion in international policy or carbon finance frameworks. Here, we examine the results of over 180 publications to synthesise evidence regarding macroalgal forest carbon sequestration potential. We show that research efforts on macroalgae carbon sequestration are heavily skewed towards particulate organic carbon (POC) pathways (77% of data publications), and that carbon fixation is the most studied flux (55%). Fluxes leading directly to carbon sequestration (e.g. carbon export or burial in marine sediments) remain poorly resolved, likely hindering regional or country-level assessments of carbon sequestration potential, which are only available from 17 of the 150 countries where macroalgal forests occur. To solve this issue, we present a framework to categorize coastlines according to their carbon sequestration potential. Finally, we review the multiple avenues through which this sequestration can translate into climate change mitigation capacity, which largely depends on whether management interventions can increase carbon removal above a natural baseline or avoid further carbon emissions. We find that conservation, restoration and afforestation interventions on macroalgal forests can potentially lead to carbon removal in the order of 10's of Tg C globally. Although this is lower than current estimates of natural sequestration value of all macroalgal habitats (61-268 Tg C year-1 ), it suggests that macroalgal forests could add to the total mitigation potential of coastal blue carbon ecosystems, and offer valuable mitigation opportunities in polar and temperate areas where blue carbon mitigation is currently low. Operationalizing that potential will necessitate the development of models that reliably estimate the proportion of production sequestered, improvements in macroalgae carbon fingerprinting techniques, and a rethinking of carbon accounting methodologies. The ocean provides major opportunities to mitigate and adapt to climate change, and the largest coastal vegetated habitat on Earth should not be ignored simply because it does not fit into existing frameworks.
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Affiliation(s)
- Albert Pessarrodona
- UWA Oceans Institute and School of Biological Sciences, University of Western Australia, Crawley, 6009, Western Australia, Australia
- Conservation International, 2011 Crystal Dr., Suite 600, Arlington, VA, USA
- International Blue Carbon Institute, 42B Boat Quay, Singapore, 049831, Singapore
| | - Rita M Franco-Santos
- CSIRO Environment, Indian Ocean Marine Research Centre, Crawley, 6009, Western Australia, Australia
| | - Luka Seamus Wright
- UWA Oceans Institute and School of Biological Sciences, University of Western Australia, Crawley, 6009, Western Australia, Australia
- CSIRO Environment, Indian Ocean Marine Research Centre, Crawley, 6009, Western Australia, Australia
| | - Mathew A Vanderklift
- CSIRO Environment, Indian Ocean Marine Research Centre, Crawley, 6009, Western Australia, Australia
| | - Jennifer Howard
- Conservation International, 2011 Crystal Dr., Suite 600, Arlington, VA, USA
- International Blue Carbon Institute, 42B Boat Quay, Singapore, 049831, Singapore
| | - Emily Pidgeon
- Conservation International, 2011 Crystal Dr., Suite 600, Arlington, VA, USA
- International Blue Carbon Institute, 42B Boat Quay, Singapore, 049831, Singapore
| | - Thomas Wernberg
- UWA Oceans Institute and School of Biological Sciences, University of Western Australia, Crawley, 6009, Western Australia, Australia
- Institute of Marine Research, Nye Flødevigveien 20, His, 4817, Norway
| | - Karen Filbee-Dexter
- UWA Oceans Institute and School of Biological Sciences, University of Western Australia, Crawley, 6009, Western Australia, Australia
- Institute of Marine Research, Nye Flødevigveien 20, His, 4817, Norway
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Luo Y, Zheng J, Ren Q, Wang Z, Huang F, Liu Z, Luo Z. Elevated nano-α-Fe 2O 3 enhances arsenic metabolism and dissolved organic carbon release of Microcystis aeruginosa under a phytate environment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:87659-87668. [PMID: 37430079 DOI: 10.1007/s11356-023-28658-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 07/03/2023] [Indexed: 07/12/2023]
Abstract
Little information is available on the effects of nano-α-Fe2O3 on arsenic (As) metabolism of algae and potential associated carbon (C) storage in As-contaminated water with dissolved organic phosphorus (DOP) as a phosphorus (P) source. In this study, Microcystis aeruginosa (M. aeruginosa) was used to investigate impacts of nano-α-Fe2O3 on cell growth and As metabolism of algae under a phytate (PA) environment as well as potential associated C storage. Results showed that nano-α-Fe2O3 had a subtle influence on algal cell growth in a PA environment. Herein, algal cell density (OD680) and chlorophyll a (Chla) were inhibited at elevated nano-α-Fe2O3 levels, which simultaneously limited the decrease of Yield. As suggested, the complexation of PA with nano-α-Fe2O3 could alleviate the negative influence on algal cell growth. Furthermore, the elevated nano-α-Fe2O3 increased As methylation in the PA environment due to higher monomethylarsenic (MMA) and dimethylarsenic (DMA) concentrations in the test media. Additionally, microcystins (MCs) in the media changed consistently with UV254, both of which were relatively lower at 10.0 mg·L-1 nano-α-Fe2O3. Enhanced As(V) methylation of algal cells was found to simultaneously reduce the release risk of As(III) and MC while increasing dissolved organic carbon (DOC) content in media, suggesting unfavorable C storage. Three-dimensional fluorescence analysis revealed that the main DOC constituent was the tryptophan-like component in aromatic proteins. Correlation analysis showed that decreases in pH and the zeta potential and an increase in Chla may lead to metabolic As improvements in M. aeruginosa. The obtained findings highlight the need for greater focus on the potential risks of DOP combined with nano-α-Fe2O3 on algal blooms as well as the biogeochemical cycling processes of As and C storage in As-contaminated water with DOP as the P source.
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Affiliation(s)
- Yinchai Luo
- Key Laboratory of Karst Dynamics, Ministry of Natural Resources (MNR) and Guangxi, Institute of Karst Geology, CAGS, Guilin, 541004, China
- College of Chemical Engineering, Huaqiao University, Xiamen, 361021, China
| | - Jieru Zheng
- College of Chemical Engineering, Huaqiao University, Xiamen, 361021, China
| | - Qiuyao Ren
- College of Chemical Engineering, Huaqiao University, Xiamen, 361021, China
| | - Zhenhong Wang
- College of Chemistry, Chemical Engineering and Environment, Minnan Normal University, Key Laboratory of Modern Separation and Analysis Science and Technology, Key Laboratory of Pollution Monitoring and Control, Zhangzhou, 363000, China
| | - Fen Huang
- Key Laboratory of Karst Dynamics, Ministry of Natural Resources (MNR) and Guangxi, Institute of Karst Geology, CAGS, Guilin, 541004, China
| | - Zixi Liu
- College of Chemical Engineering, Huaqiao University, Xiamen, 361021, China
| | - Zhuanxi Luo
- Key Laboratory of Karst Dynamics, Ministry of Natural Resources (MNR) and Guangxi, Institute of Karst Geology, CAGS, Guilin, 541004, China.
- College of Chemical Engineering, Huaqiao University, Xiamen, 361021, China.
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Photosynthetic Toxicity of Enrofloxacin on Scenedesmus obliquus in an Aquatic Environment. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19095545. [PMID: 35564941 PMCID: PMC9105898 DOI: 10.3390/ijerph19095545] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 04/25/2022] [Accepted: 04/29/2022] [Indexed: 12/30/2022]
Abstract
Aquaculture facilities are a potential source of antibiotics in aquatic environments, having adverse effects on the algae species. In this study, the toxicity induced by enrofloxacin (ENR) on the algae Scenedesmus obliquus was evaluated. The uptake of ENR and the change in the growth and photosynthesis of algae were analyzed. At the exposure doses of 10-300 μg/L, the accumulated levels of ENR in algae were 10.61-18.22 μg/g and 12.09-18.34 μg/g after 48 h and 96 h of treatment, respectively. ENR inhibited the growth of algae, with a concentration for 50% effect of 119.74 μg/L, 53.09 μg/L, 64.37 μg/L, and 52.64 μg/L after 24 h, 48 h, 72 h and 96 h of treatment, respectively, indicating the self-protection and repair ability of algae in a short period of time. Furthermore, the chlorophyll contents decreased in all treatment groups, and the photosynthetic system Ⅱ parameters decreased in a dose-dependent manner under ENR stress, suggesting that ENR caused a disorder in the electron transport of the photosynthesis of algae, and the carbon fixation and assimilation processes were thus damaged. These results indicate that ENR poses a considerable risk to aquatic environments, affects the carbon sinks, and even has an adverse effect on human health.
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