Sr isotope discrimination of multi species aquaculture productions at a worldwide scale and contribution of the water reservoir in Sr plant input

Emmanuel Delattre; Isabelle Techer; Benjamin Reneaud; Véronique Thireau; Patrick Verdoux; Philippe Prohin

doi:10.1016/j.heliyon.2019.e03075

Sr isotope discrimination of multi species aquaculture productions at a worldwide scale and contribution of the water reservoir in Sr plant input

Heliyon. 2019 Dec 26;6(1):e03075. doi: 10.1016/j.heliyon.2019.e03075. eCollection 2020 Jan.

Authors

Emmanuel Delattre¹, Isabelle Techer¹, Benjamin Reneaud¹, Véronique Thireau¹, Patrick Verdoux¹, Philippe Prohin²

Affiliations

¹ Equipe Associée 7352 CHROME, Université de Nîmes, rue du Dr. Georges Salan, 30021 Nimes, France.
² Nymphéa Distribution, 30740, Le Cailar, France.

Abstract

Aquatic plants commonly used in landscaping or as ornaments are subject to a growing worldwide market that is source of trade between countries which can induce the transfer of unwanted invasive alien plant species. To protect national biodiversity and economy, authorities promote the use of local markets without however providing the method to do so. This study deals with the feasibility of using Sr stable isotopes for discriminating the origin of aquatic plants at a worldwide scale. More than 15 aquatic plant species were collected from main producers in four countries (China, Hungary, Germany, France). Each plant was analysed for its ⁸⁷Sr/⁸⁶Sr ratio and the results are compared within samples from each producer and between countries. For a given produce, significant ⁸⁷Sr/⁸⁶Sr can be measured as a function of the plant species. However, at the scale of Europe, plants from different producers are almost isotopically identical with ⁸⁷Sr/⁸⁶Sr ratios of 0.71228 ± 218.10^-5, 0.71116 ± 178.10^-5 and 0.71066 ± 156.10^-5 for France, Hungary and Germany, respectively. These values are clearly distinguishable from those measured in Chinese aquatic plants, which yield a mean ⁸⁷Sr/⁸⁶Sr ratio of 0.70591 ± 168.10^-5. This Sr isotopic discrimination between European and Chinese aquatic plants is explained by the specific agricultural and hydrogeological environments of the producing countries. Indeed, the cycle of Sr in aquatic plants is studied here for the first time. Natural and anthropic materials of French origin were collected and characterized in terms of ⁸⁷Sr/⁸⁶Sr. Mixing models reveal that irrigation water is the main source of Sr for plants (35-85%). Clays from the substrate (4-38%) and fertilizers (5-19%) can also contribute, in proportions depending on the plant species. This model accounts for the small variations in ⁸⁷Sr/⁸⁶Sr ratios of species from the same producer and allows a discrimination between producers using different agricultural practices.

Keywords: 87Sr/86Sr; Aquatic ecology; Aquatic plants; Biogeochemistry; Environmental engineering; Environmental geochemistry; Flora; Geochemistry; Geographical origin discrimination; International trade; Isotope geochemistry; Isotopic identification; Sr-cycling.