Simultaneous use of strontium:calcium and barium:calcium ratios in otoliths as markers of habitat: Application to the European eel (Anguilla anguilla) in the Adour basin, South West France

Abstract

Sr:Ca and Ba:Ca ratios in water from the Adour estuary show a clear relationship with the salinity of the surrounding water for salinities <20, while ratios are almost constant above this level of salinity. A positive relationship was observed for the Sr:Ca ratio, whereas it was inverse for the Ba:Ca ratio. These two elemental ratios were measured in the otoliths of the European eels (Anguilla anguilla L.) using femtosecond laser ablation linked to an ICP-MS (fs-LA-ICP-MS). There was a direct relationship between the elemental ratios recorded in eel otoliths and those found in water from fresh and marine areas, suggesting that Sr:Ca and Ba:Ca ratios in eel otoliths can be used as markers of habitat in this estuary. Continuous profiling allowed the determination of three behaviour patterns in terms of habitat: freshwater, estuary and migratory individuals. Finally, the above results support the simultaneous use of both ratios for a better understanding of the migratory contingents and also as a relevant method to avoid a misidentification of environmental migratory history due to the presence of vaterite crystal in the otolith matrix.

Otolith Sr:Ca ratio and morphometry as indicators of habitat of a euryhaline species: The case of the silverside Odontesthes bonariensis

“…Debido a que existe una relación positiva entre la salinidad y la relación estroncio:calcio (Sr:Ca) del agua y del otolito de algunas especies de peces (Secor et al 1995, Zlokovitz et al 2003, Kraus y Secor 2004, Schuchert et al 2010, Tabouret et al 2010, se han desarrollado estudios que permiten relacionar parámetros del agua (Sr:Ca y salinidad) con la relación Sr:Ca de los otolitos para identificar rutas migratorias y poblaciones pesqueras (e.g., Secor et al 1995;Zlokovitz et al 2003;Tabouret et al 2010;Avigliano et al 2015bAvigliano et al , 2015c. Otra herramienta ampliamente utilizada para la determinación de poblaciones pesqueras es la morfometría del otolito (e.g., Longmore et al 2010, Cañás et al 2012, Keating et al 2014.…”

Is otolith microchemistry (Sr: Ca and Ba:Ca ratios) useful to identify Mugil curema populations in the southeastern Caribbean Sea?

“…In order to examine the relationship between otolith microchemistry and water chemistry, the mean individual elemental ratio (Sr:Ca) and the averages of all water samples within each site were compared using the partition coefficient described as (Tabouret et al, 2010) (1)…”

“…In the last decade, the analysis of otolith chemical composition has been increasingly used to study fish movements and identify fish stocks (Zlokovitz et al, 2003;Kraus and Secor, 2004;Schuchert et al, 2010;Tabouret et al, 2010;. In this regard, the determination of strontium (Sr) and barium (Ba) concentrations has proven to be of major importance (Campana, 1999;McCulloch et al, 2003;Elsdon and Gillanders, 2005;Hamer et al, 2006;Tabouret et al, 2010;.…”

“…In this regard, the determination of strontium (Sr) and barium (Ba) concentrations has proven to be of major importance (Campana, 1999;McCulloch et al, 2003;Elsdon and Gillanders, 2005;Hamer et al, 2006;Tabouret et al, 2010;. Sr concentration in otoliths was reported to vary mainly due to the chemical composition of the water where fish live (Campana, 1999;Wells et al, 2003;Kraus and Secor, 2004).…”

“…On the other hand, Ba concentrations in otoliths were found to be negatively correlated with water salinity (Miller, 2011;. For this, the simultaneous analysis of the otolith Sr:Ca and Ba:Ca ratios has been applied in previous years to study life history of fish and the differentiation of fish stocks (Tabouret et al, 2010;Ferguson et al, 2011;.…”