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Kang S.,NFRDI | Kim S.,Pukyong National University | Telmer K.,University of Victoria | Welch D.,Kintama Research Services Ltd | Lee Y.-H.,Marine Ecosystem Research Division
Ocean Science Journal | Year: 2014

Chum salmon (Oncorhynchus keta) in the North Pacific Ocean are anadromous fish, and spend most of their life in the sea until spawning in natal streams. To identify the stock and habitat characteristics of chum salmon, the composition of chemical elements (Ca, Mn, Sr, Zn, and Ba) in otolith was examined using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). Two main types of analytical work have been carried out; discrete spot analysis and line scan analysis of otolith sections. Salmon otoliths were obtained from the eastern (Canada and USA) and western (Japan and Korea) North Pacific during 1997-1999 spawning seasons. Spot analysis of otolith cores demonstrated significant differences in the element concentration among countries (p = 0.003). Line scanning from the core to the margin showed that Sr concentrations were elevated at the core of the otoliths, decreased during the freshwater stage, increased suddenly at a certain point, and oscillated periodically towards the margin matching with year-ring. The elevated Sr concentration at the core may reflect the maternal contribution to the egg, and the oscillations toward the margin may reflect salinity gradients between onshore/offshore or north/south migrations. The Zn profiles also oscillated and corresponded to the annual ring of the otolith. However, the profiles of Sr and Zn oscillated oppositely after salmon migrated to saline water and the Zn uptake declined toward the rim of the otolith while Sr uptake increased. © KSO, KIOST and Springer 2014.


Tucker S.,Canadian Department of Fisheries and Oceans | Trudel M.,Canadian Department of Fisheries and Oceans | Trudel M.,University of Victoria | Welch D.W.,Canadian Department of Fisheries and Oceans | And 6 more authors.
Marine Ecology Progress Series | Year: 2012

While recent studies have evaluated the stock-specific coastal migration of juvenile Chinook salmon, it remains unclear if these seasonal patterns are consistent between years, particularly when ocean conditions change dramatically. Here we contrast the abundance, distribution and seasonal stock compositions of juvenile Chinook salmon between years in 3 oceanographic regions of the Pacific from southern British Columbia to southeast Alaska. Between 1998 and 2008, we surveyed salmon in various months from June through March, in different regions along the shelf. Variable conditions in the North Pacific Ocean, as well as large overall shifts in ocean regimes were extensively documented over this decade. We employed genetic stock identification to identify mixed-stock compositions; fish (n = 6274) were allocated to one of 15 regional and 40 subregional stocks. Catch-per-unit-effort and distribution of salmon, as denoted by centre of mass, varied significantly between seasons, regions and years. In a similar manner, fish body size and dryweight varied significantly between years, seasons and regions. Despite these inter-annual differences in catch, distribution, fish growth performance and large variations in ocean conditions encountered by salmon over the time period of the study, we observed no response in terms of shifts in stock-specific distributions. Regional stock composition was similar between years, suggesting migration patterns for all stocks remain consistent despite fluctuations in the marine environment: local stocks remain resident in respective coastal areas during their first year at sea, except for Columbia River salmon, which move quickly into waters north of Vancouver Island in summer. © 2012 Fisheries and Oceans Canada.


Tucker S.,Canadian Department of Fisheries and Oceans | Trudel M.,Canadian Department of Fisheries and Oceans | Trudel M.,University of Victoria | Welch D.W.,Canadian Department of Fisheries and Oceans | And 6 more authors.
Transactions of the American Fisheries Society | Year: 2011

The ocean feeding grounds of juvenile Pacific salmon Oncorhynchus spp. range over several thousand kilometers in which ocean conditions, prey quality and abundance, and predator assemblages vary greatly. Therefore, the fate of individual stocks may depend on where they migrate and how much time they spend in different regions. Juvenile (n = 6,266) and immature (n = 659) Chinook salmon Oncorhynchus tshawytscha were collected from coastal Washington to Southeast Alaska in coastal trawl surveys from February to November 1998-2008, which allowed us to reconstruct changes in stock composition for seasons and regions by means of DNA stock identification techniques. Individuals were allocated to 12 regional stocks. The genetic stock assignments were directly validated by showing that 96% of the 339 known-origin, coded-wire-tagged fish were accurately allocated to their region of origin. Overall, the analyses performed in this study support the main findings of previous work based on tagging. However, given that the sample sizes for all stocks were larger and additional stocks were analyzed, we can extend those results; coastal residency of local stocks in their first year at sea with differences between smolt classes for southern stocks. Notably, yearling Chinook salmon moved quickly into waters north of the west coast of Vancouver Island, including Southeast Alaska. Furthermore, subyearling salmon were found over shallower bottom depths than yearling fish. Summer catches in all regions were dominated by Columbia River yearling fish, which suggests a rapid northward migration. In contrast, very fewColumbiaRiver subyearling fish were recovered north ofVancouver Island. Columbia River fish were a minor component of the catches in fall and winter, as fish originating from other southern stocks dominated catches off the west coast of Vancouver Island while northern British Columbia and Southeast Alaska stocks dominated northern regions during these time periods. In addition, we found no effect of hatchery origin on the distribution of fish. © American Fisheries Society 2011.


Collins A.L.,University of British Columbia | Hinch S.G.,University of British Columbia | Welch D.W.,Kintama Research Services Ltd | Cooke S.J.,Carleton University | Clark T.D.,Australian Institute of Marine Science
Transactions of the American Fisheries Society | Year: 2013

Juvenile hatchery-reared Sockeye Salmon Oncorhynchus nerka from Cultus Lake, British Columbia, were implanted during their smolt phase with one of three sizes of dummy acoustic tags to assess how tag burden (tag mass: body mass ratios ranging from 1.3% to 13.6% in air) influenced prolonged swimming performance, survival, and postsurgical wound healing in freshwater for up to 16.5 d and following a transition to seawater for 9 d. Tagged fish were compared with surgical shams and control fish (no tag, no surgery). Fish subjected to sham surgery treatments had mean swim times similar to those of control fish; however, tagged fish had a significantly lower probability of swimming the mean time of nontagged control fish. In addition, we found that the effect of tagging on swimming performance was exacerbated by tag burden and that higher tag burdens decreased the swimming performance of tagged individuals. Fish with tag burdens ≥8% had shorter swimming durations than fish with tag burdens <8%. The incisions of fish implanted with smaller tags healed more quickly than those of fish implanted with the largest tag. Overall, survival was high (≥95%) and in freshwater mortalities only occurred in fish that had tag burdens greater than 6%. These findings have important implications for studies using tagging technologies to examine the behavior and survival of migrating salmon smolts.Received October 13, 2011; accepted October 22, 2012. © 2013 Copyright Taylor and Francis Group, LLC.


Jeffries K.M.,University of British Columbia | Hinch S.G.,University of British Columbia | Gale M.K.,University of British Columbia | Clark T.D.,Australian Institute of Marine Science | And 7 more authors.
Molecular Ecology | Year: 2014

We present the first data to link physiological responses and pathogen presence with subsequent fate during migration of wild salmonid smolts. We tagged and non-lethally sampled gill tissue from sockeye salmon (Oncorhynchus nerka) smolts as they left their nursery lake (Chilko Lake, BC, Canada) to compare gene expression profiles and freshwater pathogen loads with migration success over the first ~1150 km of their migration to the North Pacific Ocean using acoustic telemetry. Fifteen per cent of smolts were never detected again after release, and these fish had gene expression profiles consistent with an immune response to one or more viral pathogens compared with fish that survived their freshwater migration. Among the significantly upregulated genes of the fish that were never detected postrelease were MX (interferon-induced GTP-binding protein Mx) and STAT1 (signal transducer and activator of transcription 1-Alpha/beta), which are characteristic of a type I interferon response to viral pathogens. The most commonly detected pathogen in the smolts leaving the nursery lake was infectious haematopoietic necrosis virus (IHNV). Collectively, these data show that some of the fish assumed to have died after leaving the nursery lake appeared to be responding to one or more viral pathogens and had elevated stress levels that could have contributed to some of the mortality shortly after release. We present the first evidence that changes in gene expression may be predictive of some of the freshwater migration mortality in wild salmonid smolts. © 2014 John Wiley & Sons Ltd.


Melnychuk M.C.,University of British Columbia | Korman J.,Ecometric Research | Hausch S.,University of Calgary | Welch D.W.,Kintama Research Services Ltd | And 2 more authors.
Canadian Journal of Fisheries and Aquatic Sciences | Year: 2014

We observed large survival differences between wild and hatchery-reared steelhead trout (Oncorhynchus mykiss) during the juvenile downstream migration immediately after release, which persisted through adult life. Following a railway spill of sodium hydroxide into the Cheakamus River, British Columbia, a short-term conservation hatchery rearing program was implemented for steelhead. We used acoustic telemetry and mark-recapture models to estimate survival of wild and (or) hatchery-reared steelhead during 4 years of the smolt migration, with both groups released in 2008. After adjusting for estimated freshwater residualization, 7%-13% of wild smolts and 30%-40% of hatchery smolts died in the first 3 km of the migration. Estimated survival from release to ocean entry was 71%-84% for wild fish and 26%-40% for hatchery fish and to exit from the Strait of Georgia system was 22%-33% for wild fish and 3.5%-6.7% for hatchery fish. A calculated 2.3-fold survival difference established during the downstream migration was similar to that after the return of adult spawners, as return rates were 8.0% for wild fish and 4.1% for hatchery fish. Contrary to current understanding, a large proportion of salmon mortality in the smolt-to-adult period, commonly termed "marine mortality", may actually occur prior to ocean entry.


Furey N.B.,University of British Columbia | Vincent S.P.,Seymour Salmonid Society | Hinch S.G.,University of British Columbia | Welch D.W.,Kintama Research Services Ltd.
PLoS ONE | Year: 2015

Variability in animal migratory behavior is expected to influence fitness, but few empirical examples demonstrating this relationship exist. The initial marine phase in the migration of juvenile salmon smolts has been identified as a potentially critical life history stage to overall population productivity, yet how fine-scale migration routes may influence survival are unknown. Large-scale acoustic telemetry studies have estimated survival rates of outmigrant Pacific salmon smolts through the Strait of Georgia (SOG) along the British Columbian coastline to the Pacific Ocean, but these data have not been used to identify and characterize fine-scale movements. Data collected on over 850 sockeye salmon (Oncorhynchus nerka) and steelhead (Oncorhynchus mykiss) smolts detected at an array in the Strait of Georgia in 2004-2008 and 2010-2013 were analyzed to characterize migration routes and link movements to subsequent survival at an array 250 km further along the marine migration pathway. Both species exhibited disproportionate use of the most eastern route in the Strait of Georgia (Malaspina Strait). While many smolts moved across the northern Strait of Georgia acoustic array with no indication of long-term milling or large-scale east-to-west movements, large proportions (20-40% of sockeye and 30-50% of steelhead) exhibited a different behavior, apparently moving in a westward or counterclockwise pattern. Variability in migratory behavior for both species was linked to subsequent survival through the Strait of Georgia. Survival for both species was influenced by initial east-to-west location, and sockeye were further influenced by migration timing and duration of time spent near the northern Strait of Georgia array. Westward movements result in a net transport of smolts from Malaspina Strait to the Strait of Georgia, particularly for steelhead. Counterclockwise movements may be due to the currents in this area during the time of outmigration, and the higher proportion of steelhead smolts exhibiting this counterclockwise behavior may reflect a greater exposure to wind-altered currents for the more surface-oriented steelhead. Our results provide an empirical example of how movements can affect migration survival, for which examples remain rare in movement ecology, confirming that variability in movements themselves are an important part of the migratory process. Copyright: © 2015 Furey et al.


Balfry S.,University of British Columbia | Balfry S.,Center for Aquaculture and Environmental Research | Welch D.W.,Kintama Research Services Ltd. | Atkinson J.,University of British Columbia | And 2 more authors.
PLoS ONE | Year: 2011

Early marine migratory behaviour and apparent survival of hatchery-reared Seymour River steelhead (Oncorhynchus mykiss) smolts was examined over a four year period (2006-2009) to assess the impact of various management strategies on improving early marine survival. Acoustically tagged smolts were released to measure their survival using estuary and coastal marine receivers forming components of the Pacific Ocean Shelf Tracking (POST) array. Early marine survival was statistically indistinguishable between releases of summer run and winter run steelhead races, night and day releases, and groups released 10 days apart. In 2009, the survival of summer run steelhead released into the river was again trialed against groups released directly into the ocean at a distance from the river mouth. Apparent survival was improved significantly for the ocean released groups. The health and physiological status of the various release groups were monitored in years 2007-2009, and results indicate that the fish were in good health, with no clinical signs of disease at the time of release. The possibility of a disease event contributing to early marine mortality was further examined in 2009 by vaccinating half of the released fish against common fish diseases (vibriosis, furunculosis). The results suggest that marine survival may be enhanced using this approach, although not to the extent observed when the smolts were transported away from the river mouth before release. In summary, direct experimental testing of different release strategies using the POST array to measure ocean survival accelerated the scientific process by allowing rapid collection of data which enabled the rejection of several existing theories and allowed tentative identification of several new alternative approaches that might improve early marine survival of Seymour River steelhead. © 2011 Balfry et al.


PubMed | University of British Columbia, Kintama Research Services Ltd. and Seymour Salmonid Society
Type: Journal Article | Journal: PloS one | Year: 2015

Variability in animal migratory behavior is expected to influence fitness, but few empirical examples demonstrating this relationship exist. The initial marine phase in the migration of juvenile salmon smolts has been identified as a potentially critical life history stage to overall population productivity, yet how fine-scale migration routes may influence survival are unknown. Large-scale acoustic telemetry studies have estimated survival rates of outmigrant Pacific salmon smolts through the Strait of Georgia (SOG) along the British Columbian coastline to the Pacific Ocean, but these data have not been used to identify and characterize fine-scale movements. Data collected on over 850 sockeye salmon (Oncorhynchus nerka) and steelhead (Oncorhynchus mykiss) smolts detected at an array in the Strait of Georgia in 2004-2008 and 2010-2013 were analyzed to characterize migration routes and link movements to subsequent survival at an array 250 km further along the marine migration pathway. Both species exhibited disproportionate use of the most eastern route in the Strait of Georgia (Malaspina Strait). While many smolts moved across the northern Strait of Georgia acoustic array with no indication of long-term milling or large-scale east-to-west movements, large proportions (20-40% of sockeye and 30-50% of steelhead) exhibited a different behavior, apparently moving in a westward or counterclockwise pattern. Variability in migratory behavior for both species was linked to subsequent survival through the Strait of Georgia. Survival for both species was influenced by initial east-to-west location, and sockeye were further influenced by migration timing and duration of time spent near the northern Strait of Georgia array. Westward movements result in a net transport of smolts from Malaspina Strait to the Strait of Georgia, particularly for steelhead. Counterclockwise movements may be due to the currents in this area during the time of outmigration, and the higher proportion of steelhead smolts exhibiting this counterclockwise behavior may reflect a greater exposure to wind-altered currents for the more surface-oriented steelhead. Our results provide an empirical example of how movements can affect migration survival, for which examples remain rare in movement ecology, confirming that variability in movements themselves are an important part of the migratory process.


PubMed | Kintama Research Services Ltd.
Type: | Journal: Scientific reports | Year: 2012

Many juvenile Snake River Chinook salmon are transported downriver to avoid hydroelectric dams in the Columbia River basin. As mortality to the final dam is 50%, transported fish should return as adults at roughly double the rate of nontransported fish; however, the benefit of transportation has not been realized consistently. Delayed mortality caused by transportation-induced stress is one hypothesis to explain reduced returns of transported fish. Differential timing of ocean entry is another. We used a large-scale acoustic telemetry array to test whether survival of transported juvenile spring Chinook is reduced relative to in-river migrant control groups after synchronizing ocean entry timing. During the initial 750km, 1 month long migration after release, we found no evidence of decreased estuarine or ocean survival of transported groups; therefore, decreased survival to adulthood for transported Chinook is likely caused by factors other than delayed effects of transportation, such as earlier ocean entry.

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