Exposure to high temperature influences the behaviour, physiology, and survival of sockeye salmon during spawning migration

2008 ◽  
Vol 86 (2) ◽  
pp. 127-140 ◽  
Author(s):  
G. T. Crossin ◽  
S. G. Hinch ◽  
S. J. Cooke ◽  
D. W. Welch ◽  
D. A. Patterson ◽  
...  

Since 1996, some populations of Fraser River sockeye salmon ( Oncorhynchus nerka Walbaum in Artedi, 1792) have begun spawning migrations weeks earlier than normal, and most perish en route as a result. We suspect that a high midsummer river temperature is the principal cause of mortality. We intercepted 100 sockeye during normal migration near a spawning stream and measured somatic energy and aspects of plasma biochemistry. Fish were then held at either 10 or 18 °C for 24 days. Before release, fish were biopsied again and implanted with acoustic transmitters. A group of biopsied but untreated control salmon were released at the same time. Sixty-two percent (8 of 13) of control salmon and 68% (21 of 31) of 10 °C salmon reached spawning areas. The 18 °C-treated fish were half as successful (35%; 6 of 17). During the holding period, mortality was 2 times higher and levels of Parvicapsula minibicornis (Kent, Whitaker and Dawe, 1997) infection were higher in the 18 °C-treated group than in the 10 °C-treated group. The only physiological difference between treatments was a change in gill Na+,K+-ATPase activity. This drop correlated negatively with travel times for the 18 °C-treated males. Reproductive-hormone levels and stress measures did not differ between treatments but showed significant correlations with individual travel times.

2006 ◽  
Vol 63 (7) ◽  
pp. 1469-1480 ◽  
Author(s):  
Steven J Cooke ◽  
Scott G Hinch ◽  
Glenn T Crossin ◽  
David A Patterson ◽  
Karl K English ◽  
...  

Beginning in 1995, segments of the late-run sockeye salmon (Oncorhynchus nerka) stocks from the Fraser River, British Columbia, have initiated upriver spawning migration up to 6 weeks earlier than historical records; and those fish have experienced high rates of en route mortality. We examined the correlations between physiological and energetic status prior to river entry with subsequent migratory performance of individual salmon using telemetry and noninvasive biopsies for Adams–Thompson–Shuswap (Adams) and Weaver–Harrison (W–H) stocks. Salmon that failed to reach the river were characterized by a tendency to have elevated levels of chronic and acute stress indicators. For one stock of fish (i.e., Adams) that entered the river, those that died before reaching spawning grounds were individuals with low gross somatic energy. Furthermore, females tended to have elevated plasma estradiol levels. When contrasting fish with different behaviours and fates, fish that did not hold in the estuary and subsequently died tended to have less energy than fish that held and reached spawning areas. Females from the former group also had higher 11-ketotestosterone and estradiol levels relative to those from the later group. These data suggest that differences in physiological and energetic status may be associated with high en route mortality in late-run sockeye salmon.


1968 ◽  
Vol 25 (6) ◽  
pp. 1115-1131 ◽  
Author(s):  
H. H. Harvey ◽  
W. S. Hoar ◽  
C. R. Bothern

When frightened, sockeye and kokanee salmon dive into deeper waters. This is termed the "sounding response."The sounding response in these fish is accompanied by the expulsion of gas from the swimbladder via the pneumatic duct. This gas loss is active and results from the contraction of the circular muscle fibers in the wall of the swimbladder.Gas loss on sounding is reduced or obviated after exposure to adrenergic blocking agents and enhanced in fish treated with sympathomimetics. Circular muscle fibers in intact and isolated strips of swimbladder contracted in response to sympathomimetics, but this response was prevented after adrenergic blockade. These results suggest the concentration of the swimbladder and associated gas expulsion is under adrenergic control.In untreated fish, an average pressure of 28.1 mm Hg was required to force gas out of the swimbladder through the pneumatic duct. In antropine-treated fish this duct-release pressure fell to an average of 0.2 mm Hg. This suggests constriction of the pneumatic duct is under cholinergic control.Histologically, the pneumatic duct was continuous with the oesophagus and extended as a convoluted duct to the anterior end of the swimbladder. Smooth muscle fibers surrounded the duct along its length and some striated fibers were present at the point where the duct joined the oesophagus. Occlusion of the pneumatic duct may be through the contraction of either of these types of fibers.The term "Gasspuckreflex" as originally used by Franz described the loss of gas from the swimbladder of physostomes in response to decompression. The authors suggest this term be reserved for this passive loss of gas, and not applied to fright-induced gas loss, resulting from active contraction of the bladder wall.


2005 ◽  
Vol 62 (9) ◽  
pp. 2124-2133 ◽  
Author(s):  
G N Wagner ◽  
S G Hinch ◽  
L J Kuchel ◽  
A Lotto ◽  
S RM Jones ◽  
...  

Adult sockeye salmon (Oncorhynchus nerka) acquire infections with the myxosporean kidney parasite Parvicapsula minibicornis during their spawning migration in the Fraser River, British Columbia. Controlled infections with this parasite in wild sockeye salmon had no significant impact on plasma ionic status, metabolic rates, and initial maximum prolonged swimming performance (Ucrit) for fish ranked as either strongly, weakly, or noninfected by polymerase chain reaction analysis of kidney tissue. However, strongly infected fish had significantly lower second Ucrit and recovery ratio (8%) values, indicating decreased ability to recover from exercise. As the present study shows that the severity of infection is affected by time and temperature, the accumulated thermal units (ATU) of exposure in this study were compared with those experienced by naturally migrating sockeye salmon. A parallel telemetry study revealed that early-timed sockeye experienced significantly more ATU (741.4 ± 29.4 °C) than normally migrating salmon (436.0 ± 20.0 °C) prior to spawning because of a significantly longer holding period in the lake system. The present data are discussed in the context of a threshold of >450 °C ATU for severe infection that would first manifest in early-timed fish in the upper reaches of the Fraser River and certainly on the spawning grounds.


2012 ◽  
Vol 69 (2) ◽  
pp. 330-342 ◽  
Author(s):  
Eduardo G. Martins ◽  
Scott G. Hinch ◽  
David A. Patterson ◽  
Merran J. Hague ◽  
Steven J. Cooke ◽  
...  

Recent studies have shown that warm temperatures reduce survival of adult migrating sockeye salmon ( Oncorhynchus nerka ), but knowledge gaps exist on where high-temperature-related mortality occurs along the migration and whether females and males are differentially impacted by river temperature. In this study, we monitored 437 radio-tagged Fraser River sockeye salmon and used capture–mark–recapture modelling approaches to investigate whether river thermal conditions differentially influence (i) spatial patterns of survival along a 413-km stretch of migration and (ii) survival of the sexes. Regardless of water temperature, survival decreased in the river section containing the most hydraulically difficult passages of the migration. However, when water temperature was warm (19 °C), survival decreased even further in the final 186 km of the migration prior to reaching the spawning grounds, particularly in females. Female and male survival differed but only when they experienced warm river temperatures. Under such conditions, the overall freshwater migration survival of males was 1.6 times higher (0.79 ± 0.09 standard error, SE) than that of females (0.50 ± 0.11 SE). As maturing female sockeye salmon maintain higher levels of plasma cortisol compared with males, we suspect that females could be immuno-compromised and thus less resistant to pathogens whose rates of development are accelerated by warm temperatures.


2010 ◽  
Vol 17 (1) ◽  
pp. 99-114 ◽  
Author(s):  
EDUARDO G. MARTINS ◽  
SCOTT G. HINCH ◽  
DAVID A. PATTERSON ◽  
MERRAN J. HAGUE ◽  
STEVEN J. COOKE ◽  
...  

1933 ◽  
Vol 8 (1) ◽  
pp. 345-355
Author(s):  
R. E. FOERSTER

Eggs spawned naturally by 3,883 females in 1925 were estimated as amounting to 17,470,000. Approximately 12,500 fry (0.07% of eggs) migrated to sea in 1926, 183,272 yearlings (1.05%) in 1927, and 1,722 two-year-olds (0.01%) in 1928, making 1.13% in all. Returning fish consisted of no three-year (32 group), 4,463 four-year (42 group), and 1,112 five-year fish (no 52 group, all being of the 53 group). None of the fish was reported returning to other spawning areas.


1952 ◽  
Vol 8c (7) ◽  
pp. 453-468 ◽  
Author(s):  
J. R. Brett

Population estimates made from observations on the number of sockeye salmon in the various spawning streams of the Skeena River, B.C., during the period 1944–48 are presented. The methods used include a fence count at Babine Lake, the most important spawing area, supplemented by stream counting in the other areas and sample tagging at Lakelse. Estimates made at Babine by the latter methods were compared with the fence counts; the stream count estimates were about one-third of the actual number present, whereas estimates from tagging were about twice the actual.A brief description of the spawning streams of the Skeena is accompanied by a map showing their location. Best estimates of 1946–47 escapements to major spawning areas are: Babine, 480,000; Morice, 70,000; Bear, 42,000; Lakelse, 29,000. These comprise 92 per cent of the total for the river system. The area of the spawning beds used by sockeye in the system is about 100 acres, or of the order of 1.5 square yards per spawning pair. The division of the whole run is approximately 45 per cent to the commercial fishery, 6 per cent to the Indian fishery, and 49 per cent escapement.


1972 ◽  
Vol 29 (6) ◽  
pp. 699-715 ◽  
Author(s):  
W. L. Hartman ◽  
R. L. Burgner

Many important, recently glaciated oligotrophic lakes that lie in coastal regions around the northern rim of the Pacific Ocean produce anadromous populations of sockeye salmon, Oncorhynchus nerka. This paper describes the limnology and fish ecology of two such lakes in British Columbia, five in Alaska, and one in Kamchatka. Then we discuss the following general topics: the biogenic eutrophication of nursery lakes from the nutrients released from salmon carcasses wherein during years of highest numbers of spawners, lake phosphate balances in Lakes Babine, Iliamna, and Dalnee are significantly affected; the use of nursery lakes by young sockeye that reveals five patterns related to size and configuration of lake basins and the distribution of spawning areas; the interactions between various life history stages of sockeye salmon and such resident predators, competitors, and prey as Arctic char, lake trout, Dolly Varden, cutthroat trout, lake whitefish, pygmy whitefish, pond smelt, sticklebacks, and sculpins; the self-regulation of sockeye salmon abundance in these nursery lakes as controlled by density-dependent processes; the interrelations between young sockeye salmon biomass and growth rates, and zooplankton abundance in Babine Lake; and finally, the diel, vertical, pelagial migratory behavior of young sockeye in Babine Lake and the new hypothesis dealing with bioenergetic conservation.


1982 ◽  
Vol 39 (11) ◽  
pp. 1444-1452 ◽  
Author(s):  
Randall M. Peterman

A method is derived to determine whether ocean abundance of a salmon stock affects either the survival rate between particular ages or the proportion of the ocean population which migrates back to freshwater spawning areas. The approach, similar to Fredin's smolt indices method, uses data on brood-year contributions to adult returns in successive years. Survival rate and proportion maturing are found to be independent of stock abundance after age 3, except in Naknek River sockeye (Oncorhynchus nerka) data. In cases such as Babine Lake sockeye salmon, where nonlinearity has been identified previously in the relation between smolt abundance and total adult returns, this lack of density dependence in the older ages means that the mortality processes which cause that nonlinearity act early in smolt life. The relations between abundance of adult returns of age n in year t and returns of age n + 1 from the same brood class in year t + 1 are useful as preseason forecasting techniques. The method derived here, which uses logarithms of abundances, improves upon the existing forecasting method. Deviations from the relation between abundances of brood-year returns can in some cases be explained by smolt weight, which is shown to affect mean age at return.Key words: salmon age structure, marine survival, age-at-return, smolt weight, preseason forecasting


1997 ◽  
Vol 54 (12) ◽  
pp. 2837-2846 ◽  
Author(s):  
Michael L Murphy ◽  
K V Koski ◽  
J Mitchel Lorenz ◽  
John F Thedinga

Migrations of juvenile Pacific salmon (Oncorhynchus spp.) in the glacial Taku River (seventh order) were studied to assess movement from upriver spawning areas (in British Columbia) into lower-river rearing areas (in Alaska). Differences between fyke-net catches in the river and seine catches in the river's estuary indicated that many downstream migrants remained in the lower river instead of migrating to sea. In particular, age-0 coho salmon (O. kisutch) and chinook salmon (O. tshawytscha) moved downriver from May to November but were not caught in the estuary. Age-0 sockeye salmon (O. nerka), coho presmolts, and other groups delayed entry into the estuary after moving downriver. We tagged groups of juvenile coho (ages 0-2) from the fyke net with coded-wire to determine when they left the river. One-third of all tags recovered from sport and commercial fisheries occurred 2-3 years later, showing that many coho remained in fresh water for 1-2 years after moving to the lower river. Lower-river areas of large glacial rivers like the Taku River can provide essential rearing habitat for juvenile salmon spawned upriver and are important to consider in integrated whole-river management of transboundary rivers.


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