Laser-sharp insights into calcification
High-resolution images help understand crucial processes
To understand more precisely how global warming and ocean acidification affect the key process of calcification and, as a consequence, the ability of corals to form reefs, highly detailed insights are necessary. Researchers at GEOMAR Helmholtz Centre for Ocean Research Kiel have now succeeded for the first time in mapping the spatial distribution and composition of the element boron in the skeleton of cold-water corals Lophelia pertusa (synonym since 2018: Desmophyllum pertusum) at high resolution. Their samples were collected at Trondheim Fjord on a research expedition with submersible JAGO in 2011. The methods and findings are described in an article published in the scientific journal Science Advances today.
To make boron and boron isotopes visible in a cross-section of the coral skeleton, the Kiel researchers used a novel imaging technique from laser ablation in combination with mass spectrometry (laser ablation multi-collector inductively coupled plasma mass spectrometer, LA-MC-ICP-MS). The images allow conclusions to be drawn about the different control mechanisms as well as the transport pathways from the external seawater to the site of calcification. These unique insights underline the need to re-evaluate and extend common calcification models. The publication presents alternatives that need to be reviewed in the future.
Publication
Fietzke, J., Wall, M. (2022): Distinct fine-scale variations in calcification control revealed by high-resolution 2D boron laser images in the cold-water coral Lophelia pertusa. In: Science Advances, doi: 10.1126/sciadv.abj4172
Image: Lophelia pertusa sample section boron laser images. a) Optical image; red rectangle indicating the area covered by high resolution LA-MC-ICP-MS (c and d). b) LA-MC-ICP-MS image of boron (10B+11B) normalized to carbon (12C) ion intensity as a semi-quantitative measure of boron concentration distribution (resolution: 100μm (LA spot size) and 80x50μm (data collection steps); image size: 17x15 mm2). c) Boron concentration image based on calibrated LA-MC-ICP-MS boron (10B+11B) normalized to carbon (12C) ion intensities. d) Boron isotope (δ11B) image obtained by LA-MC-ICP-MS, measured against NIST-SRM610 standard glass and renormalized to NBS951. The area displayed in c) and d) (resolution: 20μm (LA spot size) 15x10μm (data collection step size); image size: 1.7 x 1.5 mm2) is located within the skeletal part marked by the red square in a.
