The influence of water, diet, and temperature on 87Sr/86Sr in fin spines of juvenile Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus

• Published in: Journal of experimental marine biology and ecology 2023-11, Vol.570
• Main Authors: Neary, Joshua J., Pracheil, Brenda M., Gabitov, Rinat I., Li, Menghe H., Allen, Peter J.
• Format: Article
• Language: English
• Subjects: BASIC BIOLOGICAL SCIENCES; Fin spine; LA-ICP-MS; Microchemistry; Movement; Strontium; Sturgeon
• ISSN: 0022-0981

Analysis of microchemistry in fish fin spines offers a non-lethal approach to address key questions relating to spatial patterns and habitat use of fish. Reconstruction of life history is based on chemical changes within calcified structures with an underlying assumption of elemental incorporation relative to environmental concentration. However, information is limited on the relative influence of water and diet concentrations of elements to corresponding concentrations within fin spines. Strontium (Sr) is commonly used in trace element studies because of its predictable changes within watersheds, with recent applications showing utility of 87Sr/86Sr for greater spatial resolution. Therefore, this study evaluated the influence of water and diet 87Sr/86Sr on pectoral fin spines of Atlantic Sturgeon A. oxyrinchus oxyrinchus in controlled laboratory experiments. In the first experiment, fish were exposed to a control, water spiked with 0.10 mg/L of 87Sr or diet spiked with 0.25 µg/g or 0.50 µg/g of 87Sr in replicated tanks for 12 weeks. In a second experiment, to determine the time duration required to occupy a different environment for fin spine chemistry to change, fish were maintained in water- or diet-spiked treatments for 1, 2, 3, or 6 weeks. Additionally, to determine if temperature has an influence on 87Sr/86Sr in fin spines, fish were held at 15 and 25°C for 12 weeks. Fin spines were analyzed using laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS), and water and diet samples were analyzed using solution based ICP-MS. Results from Experiment 1 indicate water is the primary contributor and diet a secondary contributor of 87Sr/86Sr in pectoral fin spines of Atlantic Sturgeon. Results from Experiment 2 indicate fin spine 87Sr/86Sr can be influenced by water after 1 week and diet after 12 weeks. Additionally, although sample size was limited (n=3), water temperature did not have an effect on 87Sr/86Sr fin spine chemistry. In conclusion, these results provide guidance for interpretation of 87Sr/86Sr in pectoral fin spines of sturgeon and indicate usefulness of the technique for retrospectively estimating movement and habitat use.