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

• Main Authors: Zrini, Zoe Amanda, A. Kurt Gamperl
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: figshare 2021
• Subjects: 59999 Environmental Sciences not elsewhere classified; FOS Earth and related environmental sciences; Ecology; FOS Biological sciences; 69999 Biological Sciences not elsewhere classified; Inorganic Chemistry; FOS Chemical sciences; Science Policy; 111714 Mental Health; FOS Health sciences; Atlantic salmon; Salmo salar
• Online Access: https://dx.doi.org/10.6084/m9.figshare.c.5337480.v1; https://springernature.figshare.com/collections/Validating_Star-Oddi_heart_rate_and_acceleration_data_storage_tags_for_use_in_Atlantic_salmon_Salmo_salar_/5337480/1

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 (fH), 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 fH from ECGs was reduced when QI>0. Diurnal patterns of fH 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 fH declined for 2–3 weeks. During extended holding, the tag had difficulty recording low fH values 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 fH and heart rate variability (HRV) due to diurnal rhythms, and in response to temperature, activity and stressors, can be recorded.