Does the trace element composition of brown trout Salmo trutta eggs remain unchanged in spawning redds?

Abstract

The temporal stability of trace element concentrations in fertilized, artificially incubated anadromous brown trout Salmo trutta eggs and newly hatched fry was investigated. The anadromous status of the parental fish was confirmed using strontium isotopic analysis of otoliths. Whilst manganese concentrations in eggs varied over time, concentrations of aluminium, potassium, magnesium, strontium, barium and calcium were all unchanged 1 week and 6 weeks post-fertilization as well as in recently hatched larvae. The results clearly suggest that the distinctive trace element signature present in the eggs and newly hatched larvae of anadromous S. trutta (typically characterized by high strontium, low barium) is stable over time. Therefore analysis of the trace element composition of eggs is concluded to be a cost-effective and reliable method for determining the spatial and temporal extent of upstream spawning migration by anadromous salmonids. The temporal variability of at least one element in this study suggests the stability of untested multi-element signatures cannot automatically be assumed.

The prevalence of plagioclase antecrysts and xenocrysts in andesite magma, exemplified by lavas of the Tongariro volcanic complex, New Zealand

“…Sr/ 86 Sr ratios in plagioclase were measured at the Centre for Trace-Element Analysis, University of Otago using a Nu Plasma-HR multiple-collector inductively coupled plasma mass spectrometer (MC-ICPMS), coupled to a RESOlution excimer laser-ablation system (Australian Scientific Instruments and Resonetics) fitted with an M-50 laser-ablation cell (Lauren Technic Ltd and the Australian National University) (see Gabrielsson et al 2012;Coote et al 2018;Scanlan et al 2018). Laser-ablation zones were selected based on BSE imaging, and where possible, were oriented parallel to major crystal growth bands to avoid crossing major compositional domains.…”

A bioavailable strontium (87Sr/86Sr) isoscape for Aotearoa New Zealand: Implications for food forensics and biosecurity

“…Apart from food science applications, the bioavailable 87 Sr/ 86 Sr isoscape can assist with identifying the origin of new pests, unidentified materials, illegal agricultural products, and origin mislabeling. Specifically, 87 Sr/ 86 Sr can help biosecurity organizations within Aotearoa determine if a pest encountered post-border represents a newly introduced pest or an established population bearing local 87 Sr/ 86 Sr values [ 1 , 99 , 100 , 127 , 128 ]. For the key pastoral industry, Ferguson et al [ 127 ] estimated that invasive invertebrates alone cost the sector between $1.7 to $2.3 billion NZD annually.…”

“…Strontium isotope measurement of the collected plant and GNS topsoil samples was conducted at the Centre for Trace Element Analysis, University of Otago using a Nu Plasma-HR MC ICP-MS (Nu Instruments Ltd., UK) following previously reported protocols [ 76 , 95 – 99 ]. Repeated measurement of the NIST SRM 987 strontium isotope reference material (sourced from the National Institute of Standards and Technology (NIST), USA) and the HPS in-house strontium isotope standard, that bracketed every six samples, were used to monitor the accuracy and external precision of the measurements.…”

Straying of brown trout in the catchment of a large New Zealand river evaluated by otolith microchemistry

“…The assumption is based on the results of analyses of otolith microstructure completed by Dodson et al (2013) and results of YoY otolith analyses completed by Jones et al (2019) in the Taieri catchment. We avoided using the chemical composition of the area located near the core of the otolith, given this region may carry a maternal trace element signature (Gabrielsson et al, 2012). We assumed a temporal consistency in the trace element signature in the otoliths collected from the various spawning streams (see Barnett‐Johnson et al, 2010; Martin et al, 2013; Ryan et al, 2016).…”