The effect of natural radioactivity on diatom communities in mineral springs

ABSTRACT

Diatoms are good indicators of water quality because of their great diversity and wide ecological range. They are also interesting in assessing the impact of radioactivity on ecosystems because of their capacity to absorb radioelements. They also show radio-induced deformities, observed in many species. In order to assess more precisely the impact of natural radioactivity, diatom communities were monitored during a 9-month survey in two mineral springs characterized by radioactivity levels ranging within two orders of magnitude. The experimental data obtained were analyzed using different multivariate and clustering analyses. The richness was high with the dominance of Planothidium frequentissimum and Crenotia angustior. In the most radioactive spring known in Auvergne (above 4000 Bq L⁻¹ radon activity), the average deformation was 24.7%, in contrast with lower teratological rates observed in the less radioactive spring. In the absence of heavy metals, this result confirmed that radioactivity is an environmental stress for the diatoms living in these particular ecosystems. This conclusion was reinforced by the selection of springs from a database of 126 ecosystems comparable to our studied sites except the lower level of radioactivity. In these “mirror” springs, few deformations were observed.

KEYWORDS:

• Natural radioactivity
• mineral springs
• diatoms
• teratological forms
• biocenosis

Acknowledgments

Funding for this research was partly provided by the Direction Régionale de l’Environnement, de l’Aménagement et du Logement Auvergne-Rhône-Alpes, and by the Zone Atelier Territoires Uranifères. Co-funding was provided by in the framework of the DIATOMS project (LIST - Luxembourg Institute of Science and Technology). We are thankful to Pierre-Jean Gauthier for ICPMS analysis of La Montagne 1 sample and Paul Hamilton for his help to use DiaCurv. We also thank Eduardo A. Morales (Laboratório da Água, Universidade de Évora, Portugal) for his precious comments and corrections and Professor Karen K. Serieyssol for her English corrections.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Fanny Millan

Fanny Millan is a student in master’s degree at GEOLAB. Contribution: biological analysis of diatom communities, first version of article.

Cheilla Izere

Cheilla Izere is a student in master’s degree. Contribution: statistical analyses of spring data, first edition of article chapter on results.

Vincent Breton

Vincent Breton is Research Director at CNRS. After 11 years of research in hadronic physics (CNRS bronze medal, 1994), he has been studying for 20 years interfaces between physics, life sciences, health and IT. Co-author of more than 150 publications in scientific journals and peer-reviewed conference proceedings (h index: 46). Contribution: ambient gamma dosimetry measurements; water sample collection; discussion of results and development of manuscript.

Olivier Voldoire

Olivier Voldoire is engineer assistant at the CNRS. He has participated in more than 20 articles. He is specialized in scientific instrumentation and particularly in physical and chemical analyses. He participates in the research program “Biodiversity study of the diatoms of mineral springs of the French Massif Central”. Contribution: participate to the creation of Tables 1–3 and discussion of the physical and chemical results.

David G. Biron

David G. Biron is CNRS researcher. 24 years of research on “host-parasite interactions and the dynamics of biodiversity” via an integrative biology approach from the cell to the ecosystem. 62 publications in “international peer review journals”, 1 ebook (co-editor), 7 book chapters (books); 60 scientific papers in congresses (oral and posters); 48 invited lectures in laboratories and learned societies (h-index: 27). Scholarships obtained for graduates Studies (Master and Thesis, FCAR and CRSNG fellowships) and postgraduate (post-docs, Haigneré and Chateaubriand fellowships). Contribution: discussion of results and development of manuscript.

Carlos E. Wetzel

Carlos E. Wetzel is a botanist and a researcher at the Luxembourg Institute of Science and Technology. He has written over 105 articles (h-index: 15) and he has been working on diatoms in rivers, lakes and soils. He has been teaching numerous training courses on diatom ecology and taxonomy designed for biologists, technicians and ecologists, contributing to the continuous improvement in the Water Framework Directive implementation in Europe. Contribution: discussion of results and development of manuscript.

Didier Miallier

Didier Miallier is a University professor at University Clermont-Auvergne. He has written over 60 articles. He is an expert in radiological measurements. Contribution: water radon activity measurements.

Elisabeth Allain

Elisabeth Allain is a technician at the CNRS. She has participated in more than 20 articles. She is specialized in sampling treatment and preparation and works on diatoms. She participates in the research program “Biodiversity study of the diatoms of mineral springs of the French Massif Central”. Contribution: participate to the part materials and methods.

Luc Ector

Luc Ector is a botanist and senior researcher at the Luxembourg Institute of Science and Technology. He has written over 215 articles (h-index: 26) and has been working on diatoms in rivers, lakes and soils for the last 30 years. He was the President of the “Association des Diatomistes de Langue Française (ADLaF)”, which organizes annual meetings on diatom taxonomy, ecology and related subjects. Over the last 20 years, he has been organizing and teaching numerous training courses on diatom ecology and taxonomy designed for biologists, technicians and ecologists, contributing to the continuous improvement in the Water Framework Directive implementation in Europe. Contribution: provision of literature, discussion of results and development of manuscript.

Aude Beauger

Aude Beauger is an ecologist and a CNRS engineer. She has written over 30 articles and she has been working on diatoms in rivers, lakes and springs. She has been teaching on bioassessment using diatoms. She is the treasurer of the “Association des Diatomistes de Langue Française (ADLaF)” and has organized the annual meeting on diatom taxonomy, ecology and related subjects in 2014. Contribution: create the research program “Biodiversity study of the diatoms of mineral springs of the French Massif Central”, participate to the writing of the results, discussion and development of manuscript.