Juvenile Chinook salmon, Oncorhynchus tshawytscha, use of the Elwha river estuary prior to dam removal

2013 ◽  
Vol 97 (6) ◽  
pp. 731-740 ◽  
Author(s):  
Thomas P. Quinn ◽  
J. Anne Shaffer ◽  
Justin Brown ◽  
Nicole Harris ◽  
Chris Byrnes ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
River Estuary ◽  
Dam Removal ◽  
Elwha River ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook

Differential Use of the Campbell River Estuary, British Columbia by Wild and Hatchery-Reared Juvenile Chinook Salmon (Oncorhynchus tshawytscha)

1986 ◽  
Vol 43 (7) ◽  
pp. 1386-1397 ◽  
Author(s):  
C. D. Levings ◽  
C. D. McAllister ◽  
B. D. Chang
Keyword(s):  
Transition Zone ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
River Estuary ◽  
Transition Zones ◽  
Juvenile Chinook Salmon ◽  
Hatchery Fish ◽  
Mean Size ◽  
Juvenile Chinook ◽  
Marine Zone

From March 1982 to December 1983, juvenile chinook salmon (Oncorhynchus tshawytscha) were sampled by beach-seine in the Campbell River estuary and adjacent waters of Discovery Passage in order to examine estuarine use by wild and hatchery stocks. Wild juvenile chinook entered the estuary as migrant fry and were present in the estuarine zone mainly in late April to June, in the transition zone in mid-May to July, and in the marine zone in July. Hatchery fish were released from early May to early July. Maximum catches of wild stocks were similar in the estuarine and transition zones, while the maximum catches of most hatchery stocks were higher in the transition zone. For both wild and hatchery chinook, catches in the marine zone were much lower than in the estuarine and transition zones. Wild fry resided in the estuary for 40–60 d, while most hatchery fish used the estuary for about one-half this period. Wild stocks showed a relatively constant rate of increase in mean size from May to September. Higher rates of increase in the mean size of hatchery fish were shown by groups with earlier release dates and smaller mean sizes. Residency time and growth rates for wild fish were comparable with those observed in an estuary without hatchery fish. Potential for interaction between wild and hatchery stocks was greatest in the transition zone, where hatchery fish were most abundant and because hatchery releases occurred when catches of wild fish were highest in this foreshore area.

Ceratomyxa shasta (Myxozoa: Myxosporea) in juvenile chinook salmon (Oncorhynchus tshawytscha): experimental transmission and natural infections in the Fraser River, British Columbia

1985 ◽  
Vol 63 (7) ◽  
pp. 1737-1740 ◽  
Author(s):  
Susan M. Bower
Keyword(s):  
Chinook Salmon ◽  
Sockeye Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Developmental Stages ◽  
River Estuary ◽  
Fraser River ◽  
Experimental Transmission ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook ◽  
Intraperitoneal Inoculation

Ceratomyxa shasta (mainly trophozoites) from the intestinal tract of a naturally infected juvenile chinook salmon (Oncorhynchus tshawytscha) developed in the coelom of laboratory-reared chinook salmon when inoculated intraperitoneally. All developmental stages were observed. Successful subpassages were accomplished by intraperitoneal inoculation of trophozoites and sporoblasts, but an infection did not develop when these stages were pipetted into the esophagus of susceptible fish. Heavy infections, including the presence of C. shasta sporoblasts or spores, were observed in 2 of 28 feral juvenile chinook salmon seined from the Fraser River estuary in late July and early August. Trophozoite-like cells were observed in six other chinook salmon from this group. No C. shasta were observed in 15 juvenile sockeye salmon (Oncorhynchus nerka) caught in the estuary along with the chinook salmon.

Estuarine Growth of Juvenile Chinook Salmon (Oncorhynchus tshawytscha) as Inferred from Otolith Microstructure

1985 ◽  
Vol 42 (5) ◽  
pp. 899-908 ◽  
Author(s):  
John D. Neilson ◽  
Glen H. Geen ◽  
Daniel Bottom
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
River Estuary ◽  
Otolith Microstructure ◽  
Limited Growth ◽  
Juvenile Chinook Salmon ◽  
Otolith Increments ◽  
Juvenile Chinook ◽  
Elevated Water ◽  
Conversion Efficiencies

The growth of juvenile chinook salmon (Oncorhynchus tshawytscha) in the Sixes River Estuary, Oregon, was inferred from otolith microstructure. Otolith increments appeared to be formed daily, on average, and a transition between those produced during freshwater residence and estuary residence was apparent. Otolith microstructure was also examined with respect to time series of water temperature, population density, and benthic standing crop data. While the results supported the hypothesis of food-limited growth, elevated water temperatures in midsummer may have decreased food conversion efficiencies, thus also contributing to an observed growth rate decline. It was also found that from counts of otolith increments formed during freshwater life, fish that hatched relatively late tended to spend less time in freshwater before moving downstream to the estuary.

scholarly journals Managed Wetlands Can Benefit Juvenile Chinook Salmon in a Tidal Marsh

2021 ◽  
Author(s):  
Nicole M. Aha ◽  
Peter B. Moyle ◽  
Nann A. Fangue ◽  
Andrew L. Rypel ◽  
John R. Durand
Keyword(s):  
San Francisco ◽  
Growth Rates ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Nursery Habitat ◽  
San Francisco Estuary ◽  
Rice Fields ◽  
Fish Growth ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook

AbstractLoss of estuarine and coastal habitats worldwide has reduced nursery habitat and function for diverse fishes, including juvenile Chinook salmon (Oncorhynchus tshawytscha). Underutilized off-channel habitats such as flooded rice fields and managed ponds present opportunities for improving rearing conditions and increasing habitat diversity along migratory corridors. While experiments in rice fields have shown enhanced growth rates of juvenile fishes, managed ponds are less studied. To evaluate the potential of these ponds as a nursery habitat, juvenile Chinook salmon (~ 2.8 g, 63 mm FL) were reared in cages in four contrasting locations within Suisun Marsh, a large wetland in the San Francisco Estuary. The locations included a natural tidal slough, a leveed tidal slough, and the inlet and outlet of a tidally muted managed pond established for waterfowl hunting. Fish growth rates differed significantly among locations, with the fastest growth occurring near the outlet in the managed pond. High zooplankton biomass at the managed pond outlet was the best correlate of salmon growth. Water temperatures in the managed pond were also cooler and less variable compared to sloughs, reducing thermal stress. The stress of low dissolved oxygen concentrations within the managed pond was likely mediated by high concentrations of zooplankton and favorable temperatures. Our findings suggest that muted tidal habitats in the San Francisco Estuary and elsewhere could be managed to promote growth and survival of juvenile salmon and other native fishes.

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