Mapping the in situ microspatial distribution of ice algal biomass through hyperspectral imaging of sea-ice cores
Abstract Ice-associated microalgae make a significant seasonal contribution to primary production and biogeochemical cycling in polar regions. However, the distribution of algal cells is driven by strong physicochemical gradients which lead to a degree of microspatial variability in the microbial bi...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2020-12-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-020-79084-6 |
| _version_ | 1818856194144468992 |
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| author | Emiliano Cimoli Vanessa Lucieer Klaus M. Meiners Arjun Chennu Katerina Castrisios Ken G. Ryan Lars Chresten Lund-Hansen Andrew Martin Fraser Kennedy Arko Lucieer |
| author_facet | Emiliano Cimoli Vanessa Lucieer Klaus M. Meiners Arjun Chennu Katerina Castrisios Ken G. Ryan Lars Chresten Lund-Hansen Andrew Martin Fraser Kennedy Arko Lucieer |
| author_sort | Emiliano Cimoli |
| collection | DOAJ |
| description | Abstract Ice-associated microalgae make a significant seasonal contribution to primary production and biogeochemical cycling in polar regions. However, the distribution of algal cells is driven by strong physicochemical gradients which lead to a degree of microspatial variability in the microbial biomass that is significant, but difficult to quantify. We address this methodological gap by employing a field-deployable hyperspectral scanning and photogrammetric approach to study sea-ice cores. The optical set-up facilitated unsupervised mapping of the vertical and horizontal distribution of phototrophic biomass in sea-ice cores at mm-scale resolution (using chlorophyll a [Chl a] as proxy), and enabled the development of novel spectral indices to be tested against extracted Chl a (R2 ≤ 0.84). The modelled bio-optical relationships were applied to hyperspectral imagery captured both in situ (using an under-ice sliding platform) and ex situ (on the extracted cores) to quantitatively map Chl a in mg m−2 at high-resolution (≤ 2.4 mm). The optical quantification of Chl a on a per-pixel basis represents a step-change in characterising microspatial variation in the distribution of ice-associated algae. This study highlights the need to increase the resolution at which we monitor under-ice biophysical systems, and the emerging capability of hyperspectral imaging technologies to deliver on this research goal. |
| first_indexed | 2024-12-19T08:20:37Z |
| format | Article |
| id | doaj.art-7fbae12bd6e74dd4b09f4aecb0db44bd |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-12-19T08:20:37Z |
| publishDate | 2020-12-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-7fbae12bd6e74dd4b09f4aecb0db44bd2022-12-21T20:29:24ZengNature PortfolioScientific Reports2045-23222020-12-0110111710.1038/s41598-020-79084-6Mapping the in situ microspatial distribution of ice algal biomass through hyperspectral imaging of sea-ice coresEmiliano Cimoli0Vanessa Lucieer1Klaus M. Meiners2Arjun Chennu3Katerina Castrisios4Ken G. Ryan5Lars Chresten Lund-Hansen6Andrew Martin7Fraser Kennedy8Arko Lucieer9Institute for Marine and Antarctic Studies, College of Sciences and Engineering, University of TasmaniaInstitute for Marine and Antarctic Studies, College of Sciences and Engineering, University of TasmaniaAustralian Antarctic Division, Department of Agriculture, Water and the EnvironmentMax Planck Institute for Marine MicrobiologyInstitute for Marine and Antarctic Studies, College of Sciences and Engineering, University of TasmaniaSchool of Biological Sciences, Victoria University of WellingtonAquatic Biology, Department of Bioscience, Aarhus UniversityInstitute for Marine and Antarctic Studies, College of Sciences and Engineering, University of TasmaniaInstitute for Marine and Antarctic Studies, College of Sciences and Engineering, University of TasmaniaDiscipline of Geography and Spatial Sciences, School of Technology, Environments and Design, College of Sciences and Engineering, University of TasmaniaAbstract Ice-associated microalgae make a significant seasonal contribution to primary production and biogeochemical cycling in polar regions. However, the distribution of algal cells is driven by strong physicochemical gradients which lead to a degree of microspatial variability in the microbial biomass that is significant, but difficult to quantify. We address this methodological gap by employing a field-deployable hyperspectral scanning and photogrammetric approach to study sea-ice cores. The optical set-up facilitated unsupervised mapping of the vertical and horizontal distribution of phototrophic biomass in sea-ice cores at mm-scale resolution (using chlorophyll a [Chl a] as proxy), and enabled the development of novel spectral indices to be tested against extracted Chl a (R2 ≤ 0.84). The modelled bio-optical relationships were applied to hyperspectral imagery captured both in situ (using an under-ice sliding platform) and ex situ (on the extracted cores) to quantitatively map Chl a in mg m−2 at high-resolution (≤ 2.4 mm). The optical quantification of Chl a on a per-pixel basis represents a step-change in characterising microspatial variation in the distribution of ice-associated algae. This study highlights the need to increase the resolution at which we monitor under-ice biophysical systems, and the emerging capability of hyperspectral imaging technologies to deliver on this research goal.https://doi.org/10.1038/s41598-020-79084-6 |
| spellingShingle | Emiliano Cimoli Vanessa Lucieer Klaus M. Meiners Arjun Chennu Katerina Castrisios Ken G. Ryan Lars Chresten Lund-Hansen Andrew Martin Fraser Kennedy Arko Lucieer Mapping the in situ microspatial distribution of ice algal biomass through hyperspectral imaging of sea-ice cores Scientific Reports |
| title | Mapping the in situ microspatial distribution of ice algal biomass through hyperspectral imaging of sea-ice cores |
| title_full | Mapping the in situ microspatial distribution of ice algal biomass through hyperspectral imaging of sea-ice cores |
| title_fullStr | Mapping the in situ microspatial distribution of ice algal biomass through hyperspectral imaging of sea-ice cores |
| title_full_unstemmed | Mapping the in situ microspatial distribution of ice algal biomass through hyperspectral imaging of sea-ice cores |
| title_short | Mapping the in situ microspatial distribution of ice algal biomass through hyperspectral imaging of sea-ice cores |
| title_sort | mapping the in situ microspatial distribution of ice algal biomass through hyperspectral imaging of sea ice cores |
| url | https://doi.org/10.1038/s41598-020-79084-6 |
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