Innovative spectral characterisation of beached pelagic sargassum towards remote estimation of biochemical and phenotypic properties
Innovative spectral characterisation of beached pelagic sargassum towards remote estimation of biochemical and phenotypic properties
In recent years, pelagic sargassum (S. fluitans and S. natans – henceforth sargassum) macroalgal blooms have become more frequent and larger with higher biomass in the Tropical Atlantic region. They have environmental and socio-economic impacts, particularly on coastal ecosystems, tourism, fisheries and aquaculture industries, and on public health. Despite these challenges, sargassum biomass has the potential to offer commercial opportunities in the blue economy, although, it is reliant on key chemical and physical characteristics of the sargassum for specific use. In this study, we aim to utilise remotely sensed spectral profiles to determine species/morphotypes at different decomposition stages and their biochemical composition to support monitoring and valorisation of sargassum. For this, we undertook dedicated field campaigns in Barbados and Ghana to collect, for the first time, in situ spectral measurements between 350 and 2500 nm using a Spectra Vista Corp (SVC) HR-1024i field spectrometer of pelagic sargassum stranded biomass. The spectral measurements were complemented by uncrewed aerial system surveys using a DJI Phantom 4 drone and a DJI P4 multispectral instrument. Using the ground and airborne datasets this research developed an operational framework for remote detection of beached sargassum; and created spectral profiles of species/morphotypes and decomposition maps to infer biochemical composition. We were able to identify some key spectral regions, including a consistent absorption feature (920 – 1080 nm) found in all of the sargassum morphotype spectral profiles; we also observed distinction between fresh and recently beached sargassum particularly around 900 – 1000 nm. This work can support pelagic sargassum management and contribute to effective utilisation of the sargassum biomass to ultimately alleviate some of the socio-economic impacts associated with this emerging environmental challenge.
Coastal management, Macroalgae, Marine ecosystems, Remote sensing, Sargassum
Fidai, Y.A.
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Machado, C. Botelho
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Dominguez Almela, V.
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Oxenford, H.A.
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Jayson-Quashigah, P.N.
86caa2a2-ad16-4572-960b-117989e3be66
Tonon, T.
388adba4-77c4-4257-915d-0788827bcec0
Dash, J.
51468afb-3d56-4d3a-aace-736b63e9fac8
1 March 2024
Fidai, Y.A.
941762b1-5865-4263-9b51-268e9ce148a5
Machado, C. Botelho
0e50aaa1-1e26-436d-94da-37557364b6fd
Dominguez Almela, V.
c46c331c-e5ba-4da9-8f58-207a4999e02e
Oxenford, H.A.
1e6243ac-340b-48eb-8129-02c794ec826d
Jayson-Quashigah, P.N.
86caa2a2-ad16-4572-960b-117989e3be66
Tonon, T.
388adba4-77c4-4257-915d-0788827bcec0
Dash, J.
51468afb-3d56-4d3a-aace-736b63e9fac8
Fidai, Y.A., Machado, C. Botelho, Dominguez Almela, V., Oxenford, H.A., Jayson-Quashigah, P.N., Tonon, T. and Dash, J.
(2024)
Innovative spectral characterisation of beached pelagic sargassum towards remote estimation of biochemical and phenotypic properties.
Science of the Total Environment, 914, [169789].
(doi:10.1016/j.scitotenv.2023.169789).
Abstract
In recent years, pelagic sargassum (S. fluitans and S. natans – henceforth sargassum) macroalgal blooms have become more frequent and larger with higher biomass in the Tropical Atlantic region. They have environmental and socio-economic impacts, particularly on coastal ecosystems, tourism, fisheries and aquaculture industries, and on public health. Despite these challenges, sargassum biomass has the potential to offer commercial opportunities in the blue economy, although, it is reliant on key chemical and physical characteristics of the sargassum for specific use. In this study, we aim to utilise remotely sensed spectral profiles to determine species/morphotypes at different decomposition stages and their biochemical composition to support monitoring and valorisation of sargassum. For this, we undertook dedicated field campaigns in Barbados and Ghana to collect, for the first time, in situ spectral measurements between 350 and 2500 nm using a Spectra Vista Corp (SVC) HR-1024i field spectrometer of pelagic sargassum stranded biomass. The spectral measurements were complemented by uncrewed aerial system surveys using a DJI Phantom 4 drone and a DJI P4 multispectral instrument. Using the ground and airborne datasets this research developed an operational framework for remote detection of beached sargassum; and created spectral profiles of species/morphotypes and decomposition maps to infer biochemical composition. We were able to identify some key spectral regions, including a consistent absorption feature (920 – 1080 nm) found in all of the sargassum morphotype spectral profiles; we also observed distinction between fresh and recently beached sargassum particularly around 900 – 1000 nm. This work can support pelagic sargassum management and contribute to effective utilisation of the sargassum biomass to ultimately alleviate some of the socio-economic impacts associated with this emerging environmental challenge.
More information
Accepted/In Press date: 28 December 2023
e-pub ahead of print date: 3 January 2024
Published date: 1 March 2024
Additional Information:
Publisher Copyright:
© 2024 The Authors
Keywords:
Coastal management, Macroalgae, Marine ecosystems, Remote sensing, Sargassum
Identifiers
Local EPrints ID: 486007
URI: http://eprints.soton.ac.uk/id/eprint/486007
ISSN: 0048-9697
PURE UUID: 5352327d-7d21-475c-a9d7-1b5c89b6e33a
Catalogue record
Date deposited: 05 Jan 2024 17:46
Last modified: 03 May 2024 16:30
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Contributors
Author:
C. Botelho Machado
Author:
H.A. Oxenford
Author:
P.N. Jayson-Quashigah
Author:
T. Tonon
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