scholarly journals Measuring light scattering and absorption in corals with Inverse Spectroscopic Optical Coherence Tomography (ISOCT): a new tool for non-invasive monitoring

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
G. L. C. Spicer ◽  
A. Eid ◽  
D. Wangpraseurt ◽  
T. D. Swain ◽  
J. A. Winkelmann ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Properties ◽  
Light Scattering ◽  
Light Propagation ◽  
Coral Tissue ◽  
Coral Host ◽  
Invasive Monitoring ◽  
Optical Coherence ◽  
Invasive Approach ◽  
Non Invasive

Abstract The success of reef-building corals for >200 million years has been dependent on the mutualistic interaction between the coral host and its photosynthetic endosymbiont dinoflagellates (family Symbiodiniaceae) that supply the coral host with nutrients and energy for growth and calcification. While multiple light scattering in coral tissue and skeleton significantly enhance the light microenvironment for Symbiodiniaceae, the mechanisms of light propagation in tissue and skeleton remain largely unknown due to a lack of technologies to measure the intrinsic optical properties of both compartments in live corals. Here we introduce ISOCT (inverse spectroscopic optical coherence tomography), a non-invasive approach to measure optical properties and three-dimensional morphology of living corals at micron- and nano-length scales, respectively, which are involved in the control of light propagation. ISOCT enables measurements of optical properties in the visible range and thus allows for characterization of the density of light harvesting pigments in coral. We used ISOCT to characterize the optical scattering coefficient (μs) of the coral skeleton and chlorophyll a concentration of live coral tissue. ISOCT further characterized the overall micro- and nano-morphology of live tissue by measuring differences in the sub-micron spatial mass density distribution (D) that vary throughout the tissue and skeleton and give rise to light scattering, and this enabled estimates of the spatial directionality of light scattering, i.e., the anisotropy coefficient, g. Thus, ISOCT enables imaging of coral nanoscale structures and allows for quantifying light scattering and pigment absorption in live corals. ISOCT could thus be developed into an important tool for rapid, non-invasive monitoring of coral health, growth and photophysiology with unprecedented spatial resolution.

scholarly journals Microscale light management and inherent optical properties of intact corals studied with optical coherence tomography

2019 ◽  
Vol 16 (151) ◽  
pp. 20180567 ◽  
Author(s):  
Daniel Wangpraseurt ◽  
Steven Jacques ◽  
Niclas Lyndby ◽  
Jacob Boiesen Holm ◽  
Christine Ferrier Pages ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Properties ◽  
Light Scattering ◽  
Soft Tissues ◽  
Coral Species ◽  
High Efficiency ◽  
Coral Tissue ◽  
Optical Coherence ◽  
Stylophora Pistillata ◽  
Inherent Optical Properties

Coral reefs are highly productive photosynthetic systems and coral optics studies suggest that such high efficiency is due to optimized light scattering by coral tissue and skeleton. Here, we characterize the inherent optical properties, i.e. the scattering coefficient, μ s , and the anisotropy of scattering, g , of eight intact coral species using optical coherence tomography (OCT). Specifically, we describe light scattering by coral skeletons, coenoarc tissues, polyp tentacles and areas covered by fluorescent pigments (FP). Our results reveal that light scattering between coral species ranges from μ s = 3 mm −1 ( Stylophora pistillata ) to μ s = 25 mm −1 ( Echinopora lamelosa ) . For Platygyra pini , μ s was 10-fold higher for tissue versus skeleton, while in other corals (e.g. Hydnophora pilosa ) no difference was found between tissue and skeletal scattering. Tissue scattering was threefold enhanced in coenosarc tissues ( μ s = 24.6 mm −1 ) versus polyp tentacles ( μ s = 8.3 mm −1 ) in Turbinaria reniformis . FP scattering was almost isotropic when FP were organized in granule chromatophores ( g = 0.34) but was forward directed when FP were distributed diffusely in the tissue ( g = 0.96). Our study provides detailed measurements of coral scattering and establishes a rapid approach for characterizing optical properties of photosynthetic soft tissues via OCT in vivo .

scholarly journals Author Correction: Measuring light scattering and absorption in corals with Inverse Spectroscopic Optical Coherence Tomography (ISOCT): a new tool for non-invasive monitoring

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
G. L. C. Spicer ◽  
A. Eid ◽  
D. Wangpraseurt ◽  
T. D. Swain ◽  
J. A. Winkelmann ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Light Scattering ◽  
Invasive Monitoring ◽  
Optical Coherence ◽  
Non Invasive

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

scholarly journals Microscale light management and inherent optical properties of intact corals studied with optical coherence tomography

2018 ◽  
Author(s):  
Daniel Wangpraseurt ◽  
Steven Jacques ◽  
Niclas Lyndby ◽  
Jacob Boiesen Holm ◽  
Christine Ferrier Pages ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Properties ◽  
Light Scattering ◽  
Soft Tissues ◽  
Coral Species ◽  
High Efficiency ◽  
Coral Tissue ◽  
Optical Coherence ◽  
Stylophora Pistillata ◽  
Inherent Optical Properties

AbstractCoral reefs are highly productive photosynthetic systems and coral optics studies suggest that such high efficiency is due to optimised light scattering by coral tissue and skeleton. Here, we characterise the inherent optical properties, i.e., the scattering coefficient, μs, and the anisotropy of scattering, g, of 8 intact coral species using optical coherence tomography (OCT). Specifically, we describe light scattering by coral skeletons, coenoarc tissues, polyp tentacles and areas covered by fluorescent pigments (FP). Our results reveal that light scattering between coral species ranges from μs = 3 mm−1 (Stylophora pistillata) to μs= 25 mm−1 (Echinopora lamelosa). For Platygyra pini, μs was 10-fold higher for tissue vs skeleton, while in other corals (e.g. Hydnophora pilosa) no difference was found between tissue and skeletal scattering. Tissue scattering was 3-fold enhanced in coenosarc tissues (μs = 24.6 mm−1) vs polyp tentacles (μs = 8.3 mm−1) in Turbinaria reniformis. FP scattering was almost isotropic when FP were organized in granule chromatophores (g=0.34) but was forward directed when FP were distributed diffusely in the tissue (g=0.96). Our study provides detailed measurements of coral scattering and establishes a rapid approach for characterising optical properties of photosynthetic soft tissues via OCT in vivo.

scholarly journals Complementary use of Optical Coherence Tomography (OCT) and Reflection FTIR spectroscopy for in-situ non-invasive monitoring of varnish removal from easel paintings

2018 ◽  
Vol 138 ◽  
pp. 7-18 ◽  
Author(s):  
Magdalena Iwanicka ◽  
Patrizia Moretti ◽  
Saskia van Oudheusden ◽  
Marcin Sylwestrzak ◽  
Laura Cartechini ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Ftir Spectroscopy ◽  
Invasive Monitoring ◽  
Optical Coherence ◽  
Non Invasive

scholarly journals In vivoimaging of coral tissue and skeleton with optical coherence tomography

2016 ◽  
Author(s):  
Daniel Wangpraseurt ◽  
Camilla Wentzel ◽  
Steven L. Jacques ◽  
Michael Wagner ◽  
Michael Kuhl
Keyword(s):  
Optical Coherence Tomography ◽  
Surface Area ◽  
Fluorescent Protein ◽  
Coral Tissue ◽  
Optical Coherence ◽  
Pocillopora Damicornis ◽  
Dynamic Changes ◽  
Linear Contraction ◽  
Non Invasive

AbstractOptical coherence tomography (OCT) is a non-invasive three-dimensional imaging technique with micrometer resolution allowing microstructural characterization of tissuesin vivoand in real time. We present the first application of OCT forin vivoimaging of tissue and skeleton structure of intact living corals spanning a variety of morphologies and tissue thickness. OCT visualized different coral tissue layers (e.g. endoderm vs ectoderm), special structures such as mesenterial filaments and skeletal cavities, as well as mucus release from living corals. We also developed a new approach for non-invasive imaging and quantification of chromatophores containing green fluorescent protein (GFP)-like host pigment granules in coral tissue. The chromatophore system is hyper-reflective and can thus be imaged with good optical contrast in OCT, enabling quantification of chromatophore size, distribution and abundance. Because of its rapid imaging speed, OCT can also be used to quantify coral tissue movement showing that maximal linear contraction velocity was ~120 μm per second upon high light stimulation. Based on OCT imaging of tissue expansion and contraction, we made first estimates of dynamic changes in the coral tissue surface area, which varied by a factor of 2 between the contracted and expanded state of the coralPocillopora damicornis. We conclude that OCT is an excellent novel tool forin vivotomographic imaging of corals that can reveal tissue and skeleton organization as well as quantify dynamic changes in tissue structure and coral surface area non-invasively and at high spatio-temporal resolution.

scholarly journals In vivo imaging of coral tissue and skeleton with optical coherence tomography

2017 ◽  
Vol 14 (128) ◽  
pp. 20161003 ◽  
Author(s):  
Daniel Wangpraseurt ◽  
Camilla Wentzel ◽  
Steven L. Jacques ◽  
Michael Wagner ◽  
Michael Kühl
Keyword(s):  
Optical Coherence Tomography ◽  
Near Infrared ◽  
Fluorescent Protein ◽  
Coral Tissue ◽  
Coral Host ◽  
Live Coral ◽  
Optical Coherence ◽  
Linear Contraction ◽  
Green Fluorescent

Application of optical coherence tomography (OCT) for in vivo imaging of tissue and skeleton structure of intact living corals enabled the non-invasive visualization of coral tissue layers (endoderm versus ectoderm), skeletal cavities and special structures such as mesenterial filaments and mucus release from intact living corals. Coral host chromatophores containing green fluorescent protein-like pigment granules appeared hyper-reflective to near-infrared radiation allowing for excellent optical contrast in OCT and a rapid characterization of chromatophore size, distribution and abundance. In vivo tissue plasticity could be quantified by the linear contraction velocity of coral tissues upon illumination resulting in dynamic changes in the live coral tissue surface area, which varied by a factor of 2 between the contracted and expanded state of a coral. Our study provides a novel view on the in vivo organization of coral tissue and skeleton and highlights the importance of microstructural dynamics for coral ecophysiology.

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