Age estimation of barramundi (

Abstract

The age of whole otoliths from barramundi (Lates calcarifer) obtained from the southern Gulf of Carpentaria were estimated using Fourier transform near-infrared (FT-NIR) spectroscopy. Otoliths from 1716 barramundi collected in 2006, 2009 and 2012-2015 were used in this study. Partial least-squares regression models (PLS-R) and multiple linear regression models (MLR) were developed from the diffuse reflectance spectra and the age was obtained from traditional sectioned otoliths. Calibration models were built up over consecutive years (2012)(2013)(2014)(2015) by using a subset of the samples and used to predict the age of the remaining samples and samples from the following year. Results suggest that when seasonal (temporal) variability is incorporated into the calibration model, FT-NIR has the ability to predict barramundi age (validation R 2 ranged from 0.73 to 0.78; RMSEP ranged from 6.92 to 7.64 months). The predicted age class was within 1 year of the reference age in over 96% of the samples. These models were also able to predict the age of otoliths from 2006 and 2009, which were retrieved from long-term storage (validation R 2 ranged from 0.77 to 0.84; RMSEP ranged from 8.66 to 10.88 months). The results from this study have shown the potential for barramundi from the southern Gulf of Carpentaria to be aged quickly and accurately by using FT-NIR.

River flows affect the growth of a tropical finfish in the wet-dry rivers of northern Australia, with implications for water resource development

“…Commercial catches of barramundi from the Southern Gulf of Carpentaria genetic stock have been monitored annually for length, age and sex since 2000 (Fisheries Queensland, 2010). This includes collection and thinsectioning (350 to 400 lm) of sagittal otoliths for agedetermination as per standard protocols (Fisheries Queensland, 2010;2012) that have been reported on elsewhere (Wright et al, 2021). Thin-sectioned barramundi otoliths were retrieved from this historic collection for collection years between 2000 and 2018 (Supplementary Material 1).…”

Aging Pacific cod (Gadus macrocephalus) from otoliths using Fourier‐transformed near‐infrared spectroscopy

“…2020, Wright et al. 2021). Applications of this technology are emerging in other ecological disciples including non‐invasive gender identification in anurans (Vance et al.…”

“…2020, Wright et al. 2021). The model development process is complete when a predictive calibration model is evaluated against reference ages and tested by predicting a completely new set of representative unknown samples (external validation).…”

“…The goal to increase both the precision and cost efficiency of aging fish has led researchers to explore alternative age estimation techniques. In recent years, near-infrared spectroscopy (NIRs) has been explored as an alternative to microscopic age estimation to reduce cost, increase precision, and improve repeatability in estimating fish and elasmobranch ages (Wedding et al 2014, Rigby et al 2015, Passerotti et al 2020, Wright et al 2021. Applications of this technology are emerging in other ecological disciples including non-invasive gender identification in anurans (Vance et al 2014) and Chinook salmon (Hampton et al 2002) in addition to determination of dietary contents in fecal samples (Jean et al 2014).…”

“…In otoliths, these spectral signatures are a good proxy for fish age. Using multivariate calibration methods, such as partial least squares regression (PLSr), they can be related to the reference ages, which are estimated by the traditional microscopic approach (Wedding et al 2014, Rigby et al 2015, Passerotti et al 2020, Wright et al 2021. The model development process is complete when a predictive calibration model is evaluated against reference ages and tested by predicting a completely new set of representative unknown samples (external validation).…”