Effects of Some Environmental Factors on Survival, Condition, and Timing of Emergence of Chum Salmon Fry (Oncorhynchus keta)

1970 ◽  
Vol 27 (1) ◽  
pp. 196-201 ◽  
Author(s):  
L. M. Dill ◽  
T. G. Northcote
Keyword(s):  
Environmental Factors ◽  
Chum Salmon ◽  
Oncorhynchus Keta ◽  
Burial Depth ◽  
Gravel Size ◽  
Salmon Fry ◽  
Survival Condition

In an experiment in incubation channels at Robertson Creek, B.C., survival of chum salmon from planting of eggs to emergence of fry was higher in large gravel (2–4 inches, 5.1–10.2 cm) than in small gravel (0.4–1.5 inches, 1.0–3.8 cm). Neither condition coefficient nor timing of emergence was affected by gravel size. There were no significant effects of egg burial depth (8 and 12 inches, 20.3 and 30.5 cm) or density (50 and 100 per treatment) on condition coefficient, or timing of emergence.

Spawning Behavior of Chum Salmon (Oncorhynchus keta) and Rainbow Trout (Salmo gairdneri)

1975 ◽  
Vol 32 (5) ◽  
pp. 633-642 ◽  
Author(s):  
A. F. Tautz ◽  
C. Groot
Keyword(s):  
Rainbow Trout ◽  
Chum Salmon ◽  
Nest Site ◽  
Salmo Gairdneri ◽  
Oncorhynchus Keta ◽  
Spawning Behavior ◽  
Current Pattern ◽  
Chum Salmon Oncorhynchus Keta ◽  
Nest Sites ◽  
Gravel Size

Detailed accounts of the spawning behavior of chum salmon (Oncorhynchus keta) and rainbow trout (Salmo gairdneri) in laboratory flumes are provided. The behavioral activities, quivering, probing, and crossing over increase in frequency as a function of time prior to spawning whereas digging remains constant or decreases slightly. Maps of digging locations and movie films suggest nest shape and current pattern are monitored by the female, allowing her to intensify her digging activity near the center of the nest. Probing appears to be a signal to the male indicating approach of oviposition and also provides information to the female regarding the shape and suitability of the nest site. The probing act is also used in the synchronization of the male and female spawning acts. Changes in velocity do not appear to markedly affect nest construction either in terms of number of digs to oviposition or in size of nest constructed. It is inferred that velocity and gravel size are important insofar as they influence the construction of a suitable nest depression. Nest sites would appear to be selected on the basis of acceleration of flow rather than velocity per se though high limits must obviously exist.

The utilization of cold-water zooplankton as prey for chum salmon fry (Oncorhynchus keta) in Yamada Bay, Iwate, Pacific coast of northern Japan

2019 ◽  
Vol 29 ◽  
pp. 100633
Author(s):  
Yuichiro Yamada ◽  
Kei Sasaki ◽  
Kodai Yamane ◽  
Miwa Yatsuya ◽  
Yuichi Shimizu ◽  
...  
Keyword(s):  
Chum Salmon ◽  
Pacific Coast ◽  
Cold Water ◽  
Oncorhynchus Keta ◽  
Salmon Fry ◽  
Northern Japan

Behavioral Ecology of Chum Salmon Fry (Oncorhynchus keta) in a Small Estuary

1974 ◽  
Vol 31 (1) ◽  
pp. 83-92 ◽  
Author(s):  
J. C. Mason
Keyword(s):  
Fresh Water ◽  
Behavioral Ecology ◽  
Chum Salmon ◽  
Oncorhynchus Keta ◽  
Natural Systems ◽  
Active Selection ◽  
Resource Managers ◽  
Salmon Fry ◽  
Seaward Migration ◽  
And Behavior

Chum salmon fry (Oncorhynchus keta) in the estuary of a small coastal stream exploited fresh water, estuarine, and marine food chains and, by so doing, were exposed to marked, daily fluctuations in salinity that demanded active selection of fresh water on ebbing tides day and night. The resulting delay in seaward migration and associated behavioral observations are inadequately reflected in published accounts of the life history and behavior of chum fry in natural systems and laboratory situations, and the downstream displacement theory. The biological basis for delayed seaward migration of chum fry merits the attention of fishery researchers and resource managers alike.

Effects of hatchery chum salmon fry on density-dependent intra- and interspecific competition between wild chum and masu salmon fry

2014 ◽  
Vol 71 (10) ◽  
pp. 1475-1482 ◽  
Author(s):  
Koh Hasegawa ◽  
Kentaro Morita ◽  
Kazumasa Ohkuma ◽  
Tsutomu Ohnuki ◽  
Yasutaka Okamoto
Keyword(s):  
Interspecific Competition ◽  
Chum Salmon ◽  
Masu Salmon ◽  
Oncorhynchus Keta ◽  
Negative Effects ◽  
Density Dependent ◽  
Interacting Species ◽  
Salmon Fry ◽  
Foraging Rate ◽  
Principal Method

Stocking with hatchery fish is the principal method for harvest augmentation and, recently, restoring endangered populations. However, there is increasing concern about the negative effects of competition between hatchery and wild fish. In this study, enclosure experiments were conducted to evaluate the effects of hatchery chum salmon fry (Oncorhynchus keta) on wild masu (Oncorhynchus masou) and chum salmon fry through density-dependent competition. For masu and chum salmon, density-dependent performance (foraging rate and growth) varied depending on the presence or absence of competitor species. The negative effects on the foraging rate (evaluated by stomach content mass) and growth of wild masu salmon caused by wild conspecifics were greater than those exerted by wild and hatchery chum salmon. Wild chum salmon decreased foraging rate with increasing density of conspecifics and masu salmon and also in the presence of hatchery chum salmon. Although we could not evaluate growth under interspecific competition, wild chum salmon show body mass loss in the presence of hatchery chum salmon. These results suggest that the effects of stocking with hatchery chum salmon vary depending on the interacting species.

LOCOMOTOR PERFORMANCE OF CHUM SALMON FRY (ONCORHYNCHUS KETA) DURING OSMOREGULATORY ADAPTATION TO SEA WATER

1959 ◽  
Vol 37 (4) ◽  
pp. 591-605 ◽  
Author(s):  
Arthur Hillier Houston
Keyword(s):  
Chum Salmon ◽  
Sea Water ◽  
Experimental Period ◽  
Oncorhynchus Keta ◽  
Locomotor Performance ◽  
Entire Experimental Period ◽  
Salmon Fry ◽  
Initial Effect ◽  
Total Body ◽  
Slight Depression

Transfer into sea water produced an immediate and marked depression of the cruising speed of chum salmon fry. Despite considerable recovery from this initial effect the fish exhibited a continuing slight depression of cruising speed over the entire experimental period (80 hours). Variations in total body levels of chloride and water were significantly correlated with changes in cruising speed, suggesting that variations in activity might be related to the process of osmoregulatory adaptation to sea water. Possible mechanisms underlying this effect have been discussed.

Decreased Seawater Adaptability of Chum Salmon (Oncorhynchus keta) Fry Following Prolonged Rearing in Freshwater

1982 ◽  
Vol 39 (3) ◽  
pp. 509-514 ◽  
Author(s):  
Munehico Iwata ◽  
Sanae Hasegawa ◽  
Tetsuya Hirano
Keyword(s):  
Body Weight ◽  
Chum Salmon ◽  
Sea Water ◽  
Oncorhynchus Keta ◽  
Direct Transfer ◽  
Chum Salmon Oncorhynchus Keta ◽  
Salmon Fry ◽  
Seaward Migration ◽  
Osmoregulatory Ability

Chum salmon (Oncorhynchus keta) fry weighing about 1 g maintained plasma Na+ concentrations at 134–140 mmol/L during seaward migration in the Otsuchi River. The plasma Na+ level increased slightly in the estuary, and reached 150–160 mmol/L in the fry caught in the bay. On direct transfer from freshwater to seawater, the plasma Na+ concentrations of the fry weighing 0.4–2.3 g increased markedly after 1 h and reached a maximum after 3–12 h. The fry of < 1.4 g attained sea water-acclimated plasma Na+ level of 156 mmol/L within 24 h after transfer, whereas fry of 1.8–2.3 g failed to adapt to seawater within 24 h. When seawater adaptability of fry of different lots was examined simultaneously in late April, 83–109 d after hatch, the smaller fry adjusted their plasma Na+ levels more easily than the larger fry: the smallest fry attained seawater level after 12 h without showing any peak. Changes in seawater adaptability of the same lots of fry were also followed until 5 mo after hatching, and the osmoregulatory ability of the fry in seawater decreased gradually with an increase in body weight or in the time spent in freshwater.Key words: chum salmon fry, seaward migration, plasma Na+ concentration, seawater adaptability, Oncorhynchus keta

Influence of the Abundance, Size, and Yolk Reserves of Juvenile Chum Salmon (Oncorhynchus keta) on Predation by Freshwater Fishes in a Small Coastal Stream

1987 ◽  
Vol 44 (2) ◽  
pp. 236-243 ◽  
Author(s):  
Kurt L. Fresh ◽  
Steven L. Schroder
Keyword(s):  
Chum Salmon ◽  
Coho Salmon ◽  
Salmo Gairdneri ◽  
Oncorhynchus Keta ◽  
Predator Prey ◽  
Chum Salmon Oncorhynchus Keta ◽  
Salmon Fry ◽  
Juvenile Chum Salmon ◽  
Controlled Flow ◽  
The Relationship

Predator–prey interactions between juvenile chum salmon (Oncorhynchus keta) and piscivores were studied in a small coastal stream and in sections of a controlled-flow channel. The predators were primarily large [Formula: see text] rainbow trout (Salmo gairdneri) and large [Formula: see text] coho salmon (O. kisutch). The relationship between chum salmon fry abundance and the quantity consumed by predators suggested a type II functional response. Neither prey size nor prey abundance influenced predation, but predators did select fry with relatively high yolk reserves. Our results suggest that the numbers of juvenile chum salmon needed to satiate predators and to enhance fry survival are attainable by enhancement projects located on smaller rivers and streams.

Spatial variability of stream bed scour and fill: a comparison of scour depth in chum salmon (Oncorhynchus keta) redds and adjacent bed

2000 ◽  
Vol 57 (5) ◽  
pp. 928-938 ◽  
Author(s):  
Colin D Rennie ◽  
Robert G Millar
Keyword(s):  
Spatial Variability ◽  
Spatial Autocorrelation ◽  
Chum Salmon ◽  
Oncorhynchus Keta ◽  
Scour Depth ◽  
Burial Depth ◽  
Flood Events ◽  
Chum Salmon Oncorhynchus Keta ◽  
Bed Scour ◽  
Winter Flood

Scour depth in egg pockets of chum salmon (Oncorhynchus keta) egg nests (redds) in a short gravel-bed spawning reach (45 × 20 m) of Kanaka Creek, British Columbia, was not significantly different from that in the adjacent bed during 1997-1998 winter flood events, whereas the scour depth in tailspills of redds was greater. Over the course of the incubation period, none of the egg pocket locations (zero of four), all of the tailspills (three of three), and 17% of the immediately adjacent bed locations (three of 18) scoured to the assumed egg burial depth of 15 cm below the initial postspawning surface elevation. Egg pocket scour depth has not previously been monitored, and the reliance of earlier studies on tailspill monitoring as an indication of redd scour may have led to faulty assessment of embryo loss. Only one flood event, which exceeded bankfull, caused widespread and deep scour and fill. Despite implementation of the most spatially intensive array of wiffle-ball scour monitors to date, scour was so variable that there was no spatial autocorrelation of scour depths.

Changes in Body Chloride, Density, and Water Content of Chum (Oncorhynchus keta) and Coho (O. kisutch) Salmon Fry when Transferred from Fresh Water to Sea Water

1951 ◽  
Vol 8b (3) ◽  
pp. 164-177 ◽  
Author(s):  
Virginia Safford Black
Keyword(s):  
Water Content ◽  
Fresh Water ◽  
Chum Salmon ◽  
Coho Salmon ◽  
Sea Water ◽  
The Body ◽  
Oncorhynchus Keta ◽  
Normal Range ◽  
Experimental Conditions ◽  
Salmon Fry

Changes in body chloride, density and water content of chum and coho salmon fry were measured when these fish were transferred from fresh water to sea water, and the reverse. Both species tolerated 50% sea water (8–9‰ Cl). Chum fry survived direct transfer from fresh water to sea water (15–17‰ Cl), but showed a marked increase in body chloride during the first 12 hours, followed by a return to the normal range between 12 and 24 hours. Coho, however, died within the first 36 hours, after a 60% increase in chloride. Coho fry lost more water than chum fry after introduction to sea water. The density of both species approximated that of the water within an hour of transfer to the new medium. When returned to fresh water after 12 hours in sea water the body chloride, density, and water content of both species regained normal levels within 10 hours. Chum salmon go to sea as fry, whereas cohos remain in fresh water a year or more. Although coho fry seem capable of some adjustment to sea water after a preliminary period in 50% sea water, permanent acclimatization could not be demonstrated under the experimental conditions.

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