Atlantic Salmon (Salmo salar) Cage-Site Distribution, Behavior, and Physiology During a Newfoundland Heat Wave

Background: Climate change is leading to increased water temperatures and reduced oxygen levels at sea-cage sites, and this is a challenge that the Atlantic salmon aquaculture industry must adapt to it if it needs to grow sustainably. However, to do this, the industry must better understand how sea-cage conditions influence the physiology and behavior of the fish.Method: We fitted ~2.5 kg Atlantic salmon on the south coast of Newfoundland with Star-Oddi milli-HRT ACT and Milli-TD data loggers (data storage tags, DSTs) in the summer of 2019 that allowed us to simultaneously record the fish's 3D acceleration (i.e., activity/behavior), electrocardiograms (and thus, heart rate and heart rate variability), depth, and temperature from early July to mid-October.Results: Over the course of the summer/fall, surface water temperatures went from ~10–12 to 18–19.5°C, and then fell to 8°C. The data provide valuable information on how cage-site conditions affected the salmon and their determining factors. For example, although the fish typically selected a temperature of 14–18°C when available (i.e., this is their preferred temperature in culture), and thus were found deeper in the cage as surface water temperatures peaked, they continued to use the full range of depths available during the warmest part of the summer. The depth occupied by the fish and heart rate were greater during the day, but the latter effect was not temperature-related. Finally, while the fish generally swam at 0.4–1.0 body lengths per second (25–60 cm s−1), their activity and the proportion of time spent using non-steady swimming (i.e., burst-and-coast swimming) increased when feeding was stopped at high temperatures.Conclusion: Data storage tags that record multiple parameters are an effective tool to understand how cage-site conditions and management influence salmon (fish) behavior, physiology, and welfare in culture, and can even be used to provide fine-scale mapping of environmental conditions. The data collected here, and that in recent publications, strongly suggest that pathogen (biotic) challenges in combination with high temperatures, not high temperatures + moderate hypoxia (~70% air saturation) by themselves, are the biggest climate-related challenge facing the salmon aquaculture industry outside of Tasmania.

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

Animal Biotelemetry ◽

10.1186/s40317-021-00235-1 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Zoe Amanda Zrini ◽

A. Kurt Gamperl

Keyword(s):

Heart Rate ◽

Atlantic Salmon ◽

Data Storage ◽

Swimming Speed ◽

Beat Frequency ◽

Diurnal Rhythms ◽

Post Surgery ◽

Axial Acceleration ◽

Data Storage Tags ◽

Response To Temperature

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 < 30 bpm, and for this reason, in addition to the fact that the algorithm can miscalculate fH, it is highly recommended that ECGs be saved when possible for quality control and so that fH 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 fH and heart rate variability (HRV) due to diurnal rhythms, and in response to temperature, activity and stressors, can be recorded.

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Marine feeding areas and vertical movements of Atlantic salmon (Salmo salar) as inferred from recoveries of data storage tags

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2014-0562 ◽

2015 ◽

Vol 72 (7) ◽

pp. 1087-1098 ◽

Cited By ~ 14

Author(s):

Sigurður Guðjónsson ◽

Sigurður Már Einarsson ◽

Ingi Rúnar Jónsson ◽

Jóhannes Guðbrandsson

Keyword(s):

Atlantic Salmon ◽

Data Storage ◽

Salmo Salar ◽

Sea Surface ◽

Vertical Movements ◽

Atlantic Salmon Salmo Salar ◽

Irminger Sea ◽

Data Storage Tags ◽

Solar Noon ◽

Diurnal Behavior

We released 598 Atlantic salmon (Salmo salar) hatchery smolts in a river in Iceland in 2005 and 2006 tagged with data storage tags recording temperature and (depth) continuously. Five salmon returned in 2006 and two in 2007, all spending 1 year at sea. The complete temperature and depth profiles of the whole ocean migration were measured. The salmon stayed close to the surface most of the time and showed diurnal behavior, staying at slightly deeper waters during day. The salmon were in temperatures from 6 to 15 °C, with warmer temperatures in the summer. We compared the fish-recorded temperature with sea surface temperature from an available National Oceanic and Atmospheric Administration database to locate the fish at different times. Utilizing the diurnal behavior of the salmon, we estimated solar noon each day during winter. Sea surface temperatures and diurnal activity were used to estimate daily locations using established Hidden Markov Model for fish geolocation. The salmon in the study stayed southwest of Iceland in the Irminger Sea during the first summer months, but in the fall they moved towards the Faroes Islands and then back to the Irminger Sea where they stayed, until returning to the river. The salmon also took shorter and deeper dives (>100 m) during the latter part of their ocean migration.

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Heart rate and swimming activity as indicators of post-surgical recovery time of Atlantic salmon (Salmo salar)

10.21203/rs.3.rs-23506/v3 ◽

2020 ◽

Author(s):

Martin Føre ◽

Eirik Svendsen ◽

Finn Økland ◽

Albin Gräns ◽

Jo Arve Alfredsen ◽

...

Keyword(s):

Heart Rate ◽

Atlantic Salmon ◽

Data Storage ◽

Salmo Salar ◽

Recovery Time ◽

Complete Recovery ◽

Accelerometer Data ◽

Recovery Times ◽

In The Wild ◽

Fish Telemetry

Abstract Background: Fish telemetry using electronic transmitter or data storage tags has become a common method for studying free-swimming fish both in the wild and in aquaculture. However, fish used in telemetry studies must be handled, anaesthetised and often subjected to surgical procedures to be equipped with tags, processes that will shift the fish from their normal physiological and behavioural states. In many projects, information is needed on when the fish has recovered after handling and tagging so that only the data recorded after the fish has fully recovered are used in analyses. We aimed to establish recovery times of adult Atlantic salmon (Salmo salar) after an intraperitoneal tagging procedure featuring handling, anaesthesia and surgery. Results: Based on ECG and accelerometer data collected with telemetry from nine individual Atlantic salmon during the first period after tagging, we found that heart rate was initially elevated in all fish, and that it took an average of ≈4 days and a maximum of 6 days for heart rate to return to an assumed baseline level. One activity tag showed no consistent decline in activity, and two others did not show strong evidence of complete recovery by the end of the experiment: baseline levels of the remaining tags were on average reached after ≈ 3.3 days. Conclusion: Our findings showed that the Atlantic salmon used in this study required an average of ≈ 4 days, with a maximum interval of 6 days, of recovery after tagging before tag data could be considered valid. Moreover, the differences between recovery times for heart rate and activity imply that recovery time recommendations should be developed based on a combination of indicators and not just on e.g. behavioural observations.

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Heart rate and swimming activity as indicators of post-surgical recovery time of Atlantic salmon (Salmo salar)

10.21203/rs.3.rs-23506/v1 ◽

2020 ◽

Cited By ~ 1

Author(s):

Martin Føre ◽

Eirik Svendsen ◽

Finn Økland ◽

Albin Gräns ◽

Jo Arve Alfredsen ◽

...

Keyword(s):

Heart Rate ◽

Atlantic Salmon ◽

Data Storage ◽

Salmo Salar ◽

Recovery Time ◽

Activity Levels ◽

Accelerometer Data ◽

Atlantic Salmon Salmo Salar ◽

Recovery Times ◽

In The Wild

Abstract Background: Fish telemetry using electronic transmitter or data storage tags has become a common method for studying free-swimming fish both in the wild and in aquaculture. However, fish used in aquatic telemetry studies must be handled, anaesthetised and often subjected to surgical procedures to be equipped with tags, processes that will shift the fish from their normal physiological and behavioural states. In many projects, information is needed on when the fish has recovered after handling and tagging so that only the data recorded after the fish has fully recovered are used in analyses. We aimed to establish recovery times of adult Atlantic salmon (Salmo salar) after an intraperitoneal tagging procedure featuring handling, anaesthesia and surgery.Results: Based on ECG and accelerometer data collected with telemetry from nine individual Atlantic salmon during the first period after tagging, we found that heart rate was initially elevated in all fish, and that it took an average of 4 days for heart rate to return to an assumed baseline level. Although activity levels assessed from acceleration appeared to be less affected by the tagging procedure, baseline levels were on average reached after 3.4 days for this parameter.Conclusion: Our findings showed that the Atlantic salmon used in this study on average required 3-4 days of recovery after tagging before tag data could be considered valid. Moreover, the differences between recovery times for heart rate and activity imply that recovery time recommendations should be developed based on a combination of indicators and not just on e.g. behavioural observations.

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Heart rate and swimming activity as indicators of post-surgical recovery time of Atlantic salmon (Salmo salar)

10.21203/rs.3.rs-23506/v2 ◽

2020 ◽

Author(s):

Martin Føre ◽

Eirik Svendsen ◽

Finn Økland ◽

Albin Gräns ◽

Jo Arve Alfredsen ◽

...

Keyword(s):

Heart Rate ◽

Atlantic Salmon ◽

Data Storage ◽

Salmo Salar ◽

Recovery Time ◽

Activity Levels ◽

Accelerometer Data ◽

Recovery Times ◽

In The Wild ◽

Fish Telemetry

Abstract Background: Fish telemetry using electronic transmitter or data storage tags has become a common method for studying free-swimming fish both in the wild and in aquaculture. However, fish used in telemetry studies must be handled, anaesthetised and often subjected to surgical procedures to be equipped with tags, processes that will shift the fish from their normal physiological and behavioural states. In many projects, information is needed on when the fish has recovered after handling and tagging so that only the data recorded after the fish has fully recovered are used in analyses. We aimed to establish recovery times of adult Atlantic salmon (Salmo salar) after an intraperitoneal tagging procedure featuring handling, anaesthesia and surgery. Results: Based on ECG and accelerometer data collected with telemetry from nine individual Atlantic salmon during the first period after tagging, we found that heart rate was initially elevated in all fish, and that it took an average of ≈4 days and a maximum of 6 days for heart rate to return to an assumed baseline level. Although activity levels assessed from acceleration appeared to be less affected by the tagging procedure, baseline levels were on average reached after ≈ 5 days for this parameter. Conclusion: Our findings showed that the Atlantic salmon used in this study required an average of ≈ 4 days, with a maximum interval of 6 days, of recovery after tagging before tag data could be considered valid. Moreover, the differences between recovery times for heart rate and activity imply that recovery time recommendations should be developed based on a combination of indicators and not just on e.g. behavioural observations.

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Differential effects of internal tagging depending on depth treatment in Atlantic salmon: a cautionary tale for aquatic animal tag use

Current Zoology ◽

10.1093/cz/zoy093 ◽

2018 ◽

Vol 65 (6) ◽

pp. 665-673 ◽

Cited By ~ 10

Author(s):

Daniel W Wright ◽

Lars H Stien ◽

Tim Dempster ◽

Frode Oppedal

Keyword(s):

Atlantic Salmon ◽

Data Storage ◽

Animal Behavior ◽

Aquatic Animal ◽

Cautionary Tale ◽

Behavioral Differences ◽

Neutral Buoyancy ◽

Data Storage Tags ◽

And Behavior ◽

Electronic Tags

Abstract Electronic tags are widespread tools for studying aquatic animal behavior; however, tags risk behavioral manipulation and negative welfare outcomes. During an experiment to test behavioral differences of Atlantic salmon Salmo salar in different aquaculture cage types, including ones expected to elicit deeper swimming behavior, we found negative tagging effects depending on whether cages were depth-modified. In the experiment, data storage tags implanted in Atlantic salmon tracked their depth behavior and survival in unmodified sea-cages and depth-modified sea-cages that forced fish below or into a narrow seawater- or freshwater-filled snorkel tube from a 4 m net roof to the surface. All tagged individuals survived in unmodified cages; however, survival was reduced to 62% in depth-modified cages. Survivors in depth-modified cages spent considerably less time above 4 m than those in unmodified cages, and dying individuals in depth-modified cages tended to position in progressively shallower water. The maximum depth that fish in our study could attain neutral buoyancy was estimated at 22 m in seawater. We calculated that the added tag weight in water reduced this to 8 m, and subtracting the tag volume from the peritoneal cavity where the swim bladder reinflates reduced this further to 4 m. We conclude that the internal tag weight and volume affected buoyancy regulation as well as the survival and behavior of tagged fish. Future tagging studies on aquatic animals should carefully consider the buoyancy-related consequences of internal tags with excess weight in water, and the inclusion of data from dying tagged animals when estimating normal depth behaviors.

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Heart rate and swimming activity as indicators of post-surgical recovery time of Atlantic salmon (Salmo salar)

Animal Biotelemetry ◽

10.1186/s40317-020-00226-8 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

M. Føre ◽

E. Svendsen ◽

F. Økland ◽

A. Gräns ◽

J. A. Alfredsen ◽

...

Keyword(s):

Heart Rate ◽

Atlantic Salmon ◽

Data Storage ◽

Salmo Salar ◽

Recovery Time ◽

Complete Recovery ◽

Accelerometer Data ◽

Recovery Times ◽

In The Wild ◽

Fish Telemetry

Abstract Background Fish telemetry using electronic transmitter or data storage tags has become a common method for studying free-swimming fish both in the wild and in aquaculture. However, fish used in telemetry studies must be handled, anaesthetised and often subjected to surgical procedures to be equipped with tags, processes that will shift the fish from their normal physiological and behavioural states. In many projects, information is needed on when the fish has recovered after handling and tagging so that only the data recorded after the fish has fully recovered are used in analyses. We aimed to establish recovery times of adult Atlantic salmon (Salmo salar) after an intraperitoneal tagging procedure featuring handling, anaesthesia and surgery. Results Based on ECG and accelerometer data collected with telemetry from nine individual Atlantic salmon during the first period after tagging, we found that heart rate was initially elevated in all fish and that it took an average of ≈ 4 days and a maximum of 6 days for heart rate to return to an assumed baseline level. One activity tag showed no consistent decline in activity, and two others did not show strong evidence of complete recovery by the end of the experiment: baseline levels of the remaining tags were on average reached after ≈ 3.3 days. Conclusion Our findings showed that the Atlantic salmon used in this study required an average of ≈ 4 days, with a maximum interval of 6 days, of recovery after tagging before tag data could be considered valid. Moreover, the differences between recovery times for heart rate and activity imply that recovery time recommendations should be developed based on a combination of indicators and not just on e.g. behavioural observations.

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Summer Is Coming! Tackling Ocean Warming in Atlantic Salmon Cage Farming

Animals ◽

10.3390/ani11061800 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1800

Author(s):

Ricardo Calado ◽

Vasco C. Mota ◽

Diana Madeira ◽

Miguel C. Leal

Keyword(s):

Atlantic Salmon ◽

Heat Waves ◽

Seawater Temperature ◽

Ocean Warming ◽

Tolerance Limits ◽

Precision Breeding ◽

Aquaculture Industry ◽

Production Cycles ◽

Cage Aquaculture ◽

Sea Cage

Atlantic salmon (Salmo salar) cage farming has traditionally been located at higher latitudes where cold seawater temperatures favor this practice. However, these regions can be impacted by ocean warming and heat waves that push seawater temperature beyond the thermo-tolerance limits of this species. As more mass mortality events are reported every year due to abnormal sea temperatures, the Atlantic salmon cage aquaculture industry acknowledges the need to adapt to a changing ocean. This paper reviews adult Atlantic salmon thermal tolerance limits, as well as the deleterious eco-physiological consequences of heat stress, with emphasis on how it negatively affects sea cage aquaculture production cycles. Biotechnological solutions targeting the phenotypic plasticity of Atlantic salmon and its genetic diversity, particularly that of its southernmost populations at the limit of its natural zoogeographic distribution, are discussed. Some of these solutions include selective breeding programs, which may play a key role in this quest for a more thermo-tolerant strain of Atlantic salmon that may help the cage aquaculture industry to adapt to climate uncertainties more rapidly, without compromising profitability. Omics technologies and precision breeding, along with cryopreservation breakthroughs, are also part of the available toolbox that includes other solutions that can allow cage farmers to continue to produce Atlantic salmon in the warmer waters of the oceans of tomorrow.

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