Mapping the in situ microspatial distribution of ice algal biomass through hyperspectral imaging of sea-ice cores
Emiliano Cimoli
Vanessa Lucieer
Klaus M. Meiners
Arjun Chennu
Katerina Catrisios
Ken G. Ryan
Lars Cherten Lund-Hansen
Andrew Martin
Fraser Kennedy
Arko Lucieer
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.
Cimoli E., Lucieer V., Meiners K.M., Chennu A., Catrisios K., Ryan K.G., Lund-Hansen L.C., Martin A., Kennedy F. and Lucieer A. (2020) Mapping the in situ microspatial distribution of ice algal biomass through hyperspectral imaging of sea-ice cores. Scientific Reports 10. 10.1038/s41598-020-79084-6
@article{Cimoli2020,
Title = {Mapping the in situ microspatial distribution of ice algal biomass through hyperspectral imaging of sea-ice cores},
Author = {Cimoli, Emiliano and Lucieer, Vanessa and Meiners, Klaus M. and Chennu, Arjun and Catrisios, Katerina and Ryan, Ken G. and Lund-Hansen, Lars Cherten and Martin, Andrew and Kennedy, Fraser and Lucieer, Arko},
Editor = {},
Journal = {Scientific Reports},
Year = {2020},
Volume = {10},
Doi = {10.1038/s41598-020-79084-6},
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.},
}
TY - JOUR
AU - Cimoli, Emiliano
AU - Lucieer, Vanessa
AU - Meiners, Klaus M.
AU - Chennu, Arjun
AU - Catrisios, Katerina
AU - Ryan, Ken G.
AU - Lund-Hansen, Lars Cherten
AU - Martin, Andrew
AU - Kennedy, Fraser
AU - Lucieer, Arko
TI - Mapping the in situ microspatial distribution of ice algal biomass through hyperspectral imaging of sea-ice cores
T2 - Scientific Reports
PY - 2020
VL - 10
DO - 10.1038/s41598-020-79084-6
AB - 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.
ER -
