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

2015 ◽  
Vol 72 (7) ◽  
pp. 1087-1098 ◽  
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.

Otolith-derived estimates of marine temperature use by West Greenland Atlantic salmon (Salmo salar)

2015 ◽  
Vol 72 (7) ◽  
pp. 2139-2148 ◽  
Author(s):  
Vanessa Minke-Martin ◽  
J. Brian Dempson ◽  
Timothy F. Sheehan ◽  
Michael Power
Keyword(s):  
Individual Differences ◽  
Atlantic Salmon ◽  
Data Storage ◽  
Salmo Salar ◽  
Late Summer ◽  
Growth Zone ◽  
Micro Milling ◽  
West Greenland ◽  
Atlantic Salmon Salmo Salar ◽  
Preferred Temperatures

Abstract Otolith-derived estimates of mean marine temperatures used by West Greenland 1SW Atlantic salmon (Salmo salar) of North American origin were determined for fish collected in 2009 and 2010. Otolith material corresponding to the second summer at sea was subsampled, via micro-milling, and analysed by mass spectrometry to produce stable oxygen isotope (δ18O) values from which temperature use estimates were obtained from a salmonid-based fractionation equation. Mean temperature estimates did not differ significantly by period (early vs. late summer), or capture year. The mean and variation estimates were also consistent with temperature use values previously published in the literature or derived from the limited number of data storage tags that have been retrieved for Atlantic salmon, with 80% of all individuals occupying temperatures in the 3.9–9.7°C range. Among-individual differences in temperature use did not correlate with measured otolith growth zone widths. Given the temporal, spatial and methodological variation associated with the derivation of marine temperature use estimates for Atlantic salmon, the data were interpreted to define a range of preferred temperatures within which among-individual differences in growth were driven by the interaction of feeding and temperature use, possibly as a result of the opportunistic feeding behaviour known to predominate among Atlantic salmon.

scholarly journals Vertical movements of “escaped” farmed Atlantic salmon (Salmo salar L.)—a simulation study in a western Norwegian fjord

2009 ◽  
Vol 66 (2) ◽  
pp. 278-288 ◽  
Author(s):  
Ove T. Skilbrei ◽  
Jens Christian Holst ◽  
Lars Asplin ◽  
Marianne Holm
Keyword(s):  
Atlantic Salmon ◽  
Vertical Distribution ◽  
Salmo Salar ◽  
Simulation Study ◽  
Vertical Movements ◽  
Atlantic Salmon Salmo Salar ◽  
Wide Range ◽  
Norwegian Fjord ◽  
Farmed Atlantic Salmon ◽  
The Vertical Distribution

Abstract Skilbrei, O. T., Holst, J. C., Asplin, L., and Holm, M. 2009. Vertical movements of “escaped” farmed Atlantic salmon (Salmo salar L.)—a simulation study in a western Norwegian fjord. – ICES Journal of Marine Science, 66: 278–288. To study the vertical distribution of fish that had been allowed to escape, farmed Atlantic salmon were tagged with acoustic tags equipped with depth sensors, and then released on five different dates in the course of a year from two fish farms in the Hardanger Fjord in western Norway. Release stimulated the fish to dive to deeper than 15 m during the first hours or days post-release, often down to 50–80 m. However, during the following 4 weeks, most of the escapees spent most of their time above the pycnocline at depths of 0–4 m. The fish were more widely distributed in the water column after release during winter, but still spent most of the time in the cold surface layers. There was a wide range in the vertical distribution of individual fish, and the proportion of detections below 14-m depth ranged from 0 to 90%. There was a significant diurnal cycle in all seasons except midsummer, when the fish were less abundant in the upper layer during daylight, especially on brighter days. The results suggest that salmon diving activity following escape may complicate the recapture of escaped fish at the farm site but that the subsequent tendency of most fish to stay near the surface, virtually irrespective of the time of year, may facilitate recapture.

Role of Olfaction in the Behavioral and Neuronal Responses of Atlantic Salmon, Salmo salar, to Hydrographic Stratification

1985 ◽  
Vol 42 (10) ◽  
pp. 1658-1667 ◽  
Author(s):  
Kjell B. Døving ◽  
Håkan Westerberg ◽  
Peter B. Johnsen
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Water Samples ◽  
Olfactory Nerve ◽  
Control Fish ◽  
Fine Scale ◽  
Vertical Movements ◽  
Atlantic Salmon Salmo Salar ◽  
Hydrographic Features ◽  
Ultrasonic Tracking

The behavior of sham-operated and anosmic Atlantic salmon, Salmo salar, was studied in a fjord system with close reference to the fine-scale hydrographic features. Control fish made small-amplitude vertical movements, with sudden large-amplitude excursions. The anosmic fish made large continuous searches up and down in the water column, descended below the sill depth of the fjord, and followed the bottom contours. None of these three behaviors was seen in the control fish. The trauma caused by the surgical incision did not prevent the fish from active swimming, and a fish with unilateral sectioning of the olfactory nerve returned to the river of release. Activity of single olfactory bulb neurons was recorded during stimulation of salmon olfactory epithelium with water samples taken from different depths of the fjord. These water samples had been taken from regions that showed layering and to which migrating salmon demonstrated behavioral preferences in ultrasonic tracking experiments. Ninety percent of responding neurons showed differencial responses to the water samples, indicating the capacity of the olfactory system to discriminate among stratified water layers found in the ocean. We conclude that olfactory discrimination of fine-scale hydrographic features may provide a necessary reference system for successful orientation in nearshore regions by salmon.

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

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 ◽  
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.

Microstructure and texture of fresh and smoked Atlantic salmon, Salmo salar L., fillets from fish reared and slaughtered under different conditions

2001 ◽  
Vol 32 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Sjofn Sigurgisladottir ◽  
Margret S. Sigurdardottir ◽  
Helga Ingvarsdottir ◽  
Ole J. Torrissen ◽  
Hannes Hafsteinsson
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Atlantic Salmon Salmo Salar

Persistence of Orally Administered Salmonella enterica Serovars Agona and Montevideo in Atlantic Salmon (Salmo salar L.)

2005 ◽  
Vol 68 (7) ◽  
pp. 1336-1339 ◽  
Author(s):  
L. L. NESSE ◽  
T. LØVOLD ◽  
B. BERGSJØ ◽  
K. NORDBY ◽  
C. WALLACE ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Salmonella Enterica ◽  
Most Probable Number ◽  
Fish Feed ◽  
Internal Organs ◽  
Probable Number ◽  
Atlantic Salmon Salmo Salar ◽  
Gastric Intubation

The objective of our experiments was to study the persistence and dissemination of orally administered Salmonella in smoltified Atlantic salmon. In experiment 1, salmon kept at 15°C were fed for 1 week with feed contaminated with 96 most-probable-number units of Salmonella Agona per 100 g of feed and then starved for 2 weeks. Samples were taken from the gastrointestinal tract and examined for Salmonella 1, 2, 8, 9, 15, and 16 days after the feeding ended. In experiment 2, Salmonella Agona and Montevideo were separately mixed with feed and administered by gastric intubation. Each fish received 1.0 × 108, 1.0 × 106, or 1.0 × 104 CFU. The different groups were kept in parallel at 5 and 15°C and observed for 4 weeks. Every week, three fish in each group were sacrificed, and samples were taken from the skin, the pooled internal organs, the muscle, and the gastrointestinal tract and examined for the presence of Salmonella. The results from the two experiments showed that the persistence of Salmonella in the fish was highly dependent on the dose administered. Salmonella was not recovered from any of the fish that were fed for 1 week with the lowest concentration of Salmonella. In the fish given the highest dose of Salmonella, bacteria persisted for at least 4 weeks in the gastrointestinal tract as well as, to some extent, the internal organs. The present study shows that under practical conditions in Norway, the risk of Salmonella in fish feed being passed on to the consumer of the fish is negligible.

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