Validating Star-Oddi heart rate and acceleration data storage tags for use in Atlantic salmon (Salmo salar)

• Published in: Animal Biotelemetry
• Main Authors: Zoe Amanda Zrini, A. Kurt Gamperl
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2021
• Subjects: Data storage tags; Atlantic salmon; Heart rate; Surgical recovery; Acceleration; Swimming speed; Ecology; QH540-549.5; Animal biochemistry; QP501-801; Salmo salar
• Online Access: https://doi.org/10.1186/s40317-021-00235-1; https://doaj.org/article/7240353298b14c19bb80051dd5170e49

Abstract Background Data storage tags (DSTs) record and store information about animals and their environment, and can provide important data relevant to fish culture, ecology and conservation. A DST has recently been developed that records heart rate (f H), electrocardiograms (ECGs), tri-axial acceleration and temperature. However, at the time of this study, no research using these tags had been performed on fish or determined the quality of the data collected. Thus, our research asked: do these DSTs provide reliable and meaningful data? To examine this question, Atlantic salmon (1.4 ± 0.7 kg) were implanted with DSTs, then swam at increasing speeds in a swim tunnel after 1 week of recovery. Further, in two separate experiments, salmon (2.4 ± 0.1 kg) were implanted with DSTs and held in a large tank with conspecifics for 1 week at 11 °C or 6 weeks at 8–12 °C. Results External acceleration (EA) and variation in EA (VAR) increased exponentially with swimming speed and tail beat frequency. The quality index (QI) assigned to ECG recordings (where QI0 means very good quality, and QI1, QI2 and QI3 are of reduced quality) did not change significantly with increasing swimming speed (QI0 ~ 60–80%). However, we found that the accuracy of the tag algorithm in estimating f H from ECGs was reduced when QI>0. Diurnal patterns of f H and EA were evident from the time the salmon were placed in the tank. Heart rate appeared to stabilize by ~ 4 days post-surgery in the first experiment, but extended holding showed that f H declined for 2–3 weeks. During extended holding, the tag had difficulty recording low f H values < 30 bpm, and for this reason, in addition to the fact that the algorithm can miscalculate f H, it is highly recommended that ECGs be saved when possible for quality control and so that f H values with QI>0 can be manually calculated. Conclusions With these DSTs, parameters of acceleration can be used to monitor the activity of free-swimming salmon. Further, changes in f H and heart rate variability (HRV) ...