A transformative approach to ageing fish otoliths using Fourier transform-near infrared spectroscopy (NIRS): a case study of eastern Bering Sea walleye pollock (Gadus chalcogrammus)

• Main Authors: Helser, Thomas E, Benson, Irina, Erickson, Jason, Healy, Jordan, Kastelle, Craig R, Short, Jonathan A.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: NRC Research Press (a division of Canadian Science Publishing) 2018
• Subjects: Bering Sea
• Online Access: http://hdl.handle.net/1807/93158; http://www.nrcresearchpress.com/doi/abs/10.1139/cjfas-2018-0112

We investigated the use of Fourier transform-near infrared spectroscopy (FT-NIRS), which is a method of measuring light absorbance signatures, to derive ages from eastern Bering Sea walleye pollock (Gadus chalcogrammus) otoliths. This approach is based on a predictive model between near infrared spectra in the otolith and fish age, which is calibrated and validated. The advantage of FT-NIRS over traditional methods is the speed and repeatability with which age estimates are generated. The application of FT-NIRS to walleye Pollock otoliths yielded r2 values between 0.91 and 0.95 for the calibration models, and good validation performance (between 0.82 and 0.93). This approach can be expected to predict fish age within Âą 1.0 year of age 67% of the time. When comparing approaches, the FT-NIRS had as good or slightly better precision (75% agreement) than the traditional ageing (66% agreement), and showed little or no bias at age before 12 years of age. Once the predictive FT-NIR model is calibrated and validated, age-estimates using FT-NIRS can be done at 10 times the rate compared to traditional methods. The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author.