Fjord migration and survival of wild and hatchery-reared Atlantic salmon and wild brown trout post-smolts

Thorstad, Eva B.; Økland, Finn; Finstad, Bengt; Sivertsgård, Rolf; Plantalech, Núria; Bjørn, Pål Arne; McKinley, R. S.

doi:10.1007/978-1-4020-6237-7_11

Cited by 41 publications

(86 citation statements)

References 24 publications

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“…While estimates of swimming speed show some variability (e.g. from 0.53 body lengths per second (bl s −1 ) [58] up to 4 bl s −1 [52]), an average routine rate of 1 bl s −1 is common [63]. Laboratory swimming respirometry studies have found that a speed of 1 bl s −1 is associated with a minimum gross cost of transport [64].…”

Section: Resultsmentioning

confidence: 99%

A Synthesis of Tagging Studies Examining the Behaviour and Survival of Anadromous Salmonids in Marine Environments

et al. 2012

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This paper synthesizes tagging studies to highlight the current state of knowledge concerning the behaviour and survival of anadromous salmonids in the marine environment. Scientific literature was reviewed to quantify the number and type of studies that have investigated behaviour and survival of anadromous forms of Pacific salmon (Oncorhynchus spp.), Atlantic salmon (Salmo salar), brown trout (Salmo trutta), steelhead (Oncorhynchus mykiss), and cutthroat trout (Oncorhynchus clarkii). We examined three categories of tags including electronic (e.g. acoustic, radio, archival), passive (e.g. external marks, Carlin, coded wire, passive integrated transponder [PIT]), and biological (e.g. otolith, genetic, scale, parasites). Based on 207 papers, survival rates and behaviour in marine environments were found to be extremely variable spatially and temporally, with some of the most influential factors being temperature, population, physiological state, and fish size. Salmonids at all life stages were consistently found to swim at an average speed of approximately one body length per second, which likely corresponds with the speed at which transport costs are minimal. We found that there is relatively little research conducted on open-ocean migrating salmonids, and some species (e.g. masu [O. masou] and amago [O. rhodurus]) are underrepresented in the literature. The most common forms of tagging used across life stages were various forms of external tags, coded wire tags, and acoustic tags, however, the majority of studies did not measure tagging/handling effects on the fish, tag loss/failure, or tag detection probabilities when estimating survival. Through the interdisciplinary application of existing and novel technologies, future research examining the behaviour and survival of anadromous salmonids could incorporate important drivers such as oceanography, tagging/handling effects, predation, and physiology.

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Section: Resultsmentioning

confidence: 99%

A Synthesis of Tagging Studies Examining the Behaviour and Survival of Anadromous Salmonids in Marine Environments

et al. 2012

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“…Anadromity is a more characteristic lifehistory event of salmon than of trout. While salmon quickly leave estuarine and coastal areas and enter full strength seawater (Finstad et al 1989;Thorstad et al 2007), brown trout/sea trout and other salmonids (e.g. Arctic charr) may reside in or close to the estuaries for most of the marine life stage, thus reducing the need for complete preadaptation of ion regulatory capacity to full strength seawater (Bystriansky et al 2006).…”

Section: Discussionmentioning

confidence: 99%

“…Atlantic salmon smolts quickly leave estuarine and coastal areas and enter full strength seawater, while brown trout and other salmonid smolts [e.g. Arctic char (Salvelinus alpinus L.)] may reside in low salinity areas for much of the marine life stage (Lacroix and McCurdy 1996;Bystriansky et al 2006;Thorstad et al 2007). Thus, they have a reduced need for complete preadaptation of ion regulatory capacity to full strength seawater (Finstad et al 1989;Bystriansky et al 2006).…”

Section: Introductionmentioning

confidence: 99%

Seawater tolerance in Atlantic salmon, Salmo salar L., brown trout, Salmo trutta L., and S. salar × S. trutta hybrids smolt

Urke

Koksvik

Arnekleiv

et al. 2009

Fish Physiol Biochem

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High levels of hybridization between Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) have been reported in the Gyrodactylus salaris infected Rivers Vefsna and Driva in Norway. The survival and behaviour during the sea phase of such hybrids is unknown. The reported work documents ionoregulatory status after 24 h seawater challenge tests (24hSW) and gill Na+/K+-ATPase (NKA) activity of migrating wild smolts of Atlantic salmon, brown trout and hybrids at two sampling dates during the 2006 smolt run in River Driva. Salmon, trout and hybrids contributed to 27, 52 and 21% of the catches, respectively. The large contribution of hybrids suggests both a high hybridization rate and a high survival rate from fry to smolt. Both salmon and hybrids had a well-developed seawater tolerance at the time of downstream migration, revealed by small ionoregulatory effects and no or low mortality rates during the 24hSW tests. The trout were not fully adapted to seawater, and high mortality rates were observed (71 and 92%) during the 24hSW tests. The NKA activity was not significantly different between salmon and hybrids. Most of the hybrids were physiologically capable of direct entry to full strength seawater. The incomplete seawater tolerance in trout compared to salmon corresponds well with differences in life-history patterns between these two species. The life history strategy of the hybrids during the sea phase is not known, and further investigations on the marine behaviour and survival is needed to evaluate the role of hybrids in the risk of spreading G. salaris to nearby river systems.

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“…This indicates that either all groups of brown trout suffered a high mortality in the fjord system, or that they stayed in parts of the system not covered by the listening stations. New results also indicate that predation risk can be very high in estuarine and inner fjord areas (Thorstad et al, 2007;Niels Jepsen, pers. comm.).…”

Section: Discussionmentioning

confidence: 93%

Effects of salmon lice infection and salmon lice protection on fjord migrating Atlantic salmon and brown trout post-smolts

Sivertsgård¹,

Thorstad²,

Økland³

et al. 2007

Hydrobiologia

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Effects of artificial salmon lice infection and pharmaceutical salmon lice prophylaxis on survival and rate of progression of Atlantic salmon (n = 72) and brown trout post-smolts (n = 72) during their fjord migration, were studied by telemetry. The infected groups were artificially exposed to infective salmon lice larvae in the laboratory immediately before release in the inner part of the fjord to simulate a naturally high infection pressure. Groups of infected Atlantic salmon (n = 20) and brown trout (n = 12) were also retained in the hatchery to control the infection intensity and lice development during the study period. Neither salmon lice infection nor pharmaceutical prophylaxis had any effects on survival and rate of progression of fjord migrating Atlantic salmon post-smolts compared to control fish. Atlantic salmon spent on average only 151.2 h (maximum 207.3 h) in passing the 80 km fjord system and had, thus, entered the ocean when the more pathogenic pre-adult and adult lice stages developed. The brown trout, in comparison to Atlantic salmon, remained to a larger extent than Atlantic salmon in the inner part of the fjord system. No effect of salmon lice infection, or protection, was found in brown trout during the first weeks of their fjord migration. Brown trout will, to a larger extent than Atlantic salmon, stay in the fjord areas when salmon lice infections reach the more pathogenic pre-adult and adult stages. In contrast to Atlantic salmon, they will thereby possess the practical capability of returning to freshwater when encountering severe salmon lice attacks.

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Fjord migration and survival of wild and hatchery-reared Atlantic salmon and wild brown trout post-smolts

Cited by 41 publications

References 24 publications

A Synthesis of Tagging Studies Examining the Behaviour and Survival of Anadromous Salmonids in Marine Environments

A Synthesis of Tagging Studies Examining the Behaviour and Survival of Anadromous Salmonids in Marine Environments

Seawater tolerance in Atlantic salmon, Salmo salar L., brown trout, Salmo trutta L., and S. salar × S. trutta hybrids smolt

Effects of salmon lice infection and salmon lice protection on fjord migrating Atlantic salmon and brown trout post-smolts

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