Assessment of the Impact of the Myxosporean Parasite Ceratomyxa shasta on Survival of Seaward Migrating Juvenile Chinook Salmon, Oncorhynchus tshawytscha, from the Fraser River, British Columbia

1992 ◽  
Vol 49 (9) ◽  
pp. 1883-1889 ◽  
Author(s):  
L. Margolis ◽  
T. E. McDonald ◽  
D. J. Whitaker
Keyword(s):  
British Columbia ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Infected Fish ◽  
Migration Route ◽  
Fraser River ◽  
Juvenile Chinook Salmon ◽  
Myxosporean Parasite ◽  
Juvenile Chinook ◽  
The Impact

Approximately 3.3% of more than 3500 seaward migrating juvenile chinook salmon (Oncorhynchus tshawytscha) collected from the lower reaches and off the mouth of the Fraser River, British Columbia, between March and August 1985–87 were infected with Ceratomyxa shasta (Protozoa: Myxosporea). The fish were held live for up to 151 d before examination to allow the infections to become patent. The first infected fish were detected in samples taken in late May to early June, approximately 4 wk after the river water temperature had reached 10 °C. By this time, 40–65% of the fish had been collected, indicating that the majority of the juvenile chinook salmon had left the Fraser River before the infective stage of the parasite was present. Significant differences in prevalence of C. shasta were associated with both the migration route chosen by the fish and their age. Fish that used the lower flow rate North Arm had a greater prevalence (6.8%) of infection than those that migrated down the Main Arm (2.1%). Age 0 fish had a significantly higher prevalence (5.2%) of C. shasta than the age 1 group (1.5%). It is concluded that C. shasta is not a major cause of mortality of downstream migrating juvenile Fraser River chinook salmon.

Susceptibility of six Fraser chinook salmon stocks to Ceratomyxa shasta and the effects of salinity on ceratomyxosis

1984 ◽  
Vol 62 (6) ◽  
pp. 1081-1083 ◽  
Author(s):  
Hilda Lei Ching ◽  
D. R. Munday
Keyword(s):  
Chinook Salmon ◽  
Drainage System ◽  
Infected Fish ◽  
Estuarine Environment ◽  
Fish Stock ◽  
Fraser River ◽  
Time Of Death ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook ◽  
High Level

Juvenile chinook salmon representing six stocks from the Fraser River drainage system were tested for susceptibility to the myxozoan pathogen, Ceratomyxa shasta. Of the six stocks tested, three were collected from the Nechako, Quesnel, and Clearwater rivers and three were hatchery stocks originating from Slim Creek and the Bowron and Birkenhead rivers. Of 302 fish exposed in August 1982, 95% became infected and died of ceratomyxosis. Susceptibility was high and time of death varied with the fish stock. High river temperatures during the 10 days of exposure and a high level of abundance of infectious C. shasta contributed to high mortalities of fish. Results of maintenance of infected fish in seawater indicated that ceratomyxosis is not attenuated and fish will continue to die after entering the estuarine environment.

Bioconcentration of Chlorophenols by Juvenile Chinook Salmon (Oncorhynchus tshawytscha) Overwintering in the Upper Fraser River: Field and Laboratory Tests

1988 ◽  
Vol 23 (1) ◽  
pp. 100-113 ◽  
Author(s):  
I. H. Rogers ◽  
J. A. Servizi ◽  
C. D. Levings
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Cold Water ◽  
Pulp Mill ◽  
Wood Preservative ◽  
Fraser River ◽  
Reference Sites ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook ◽  
River Fish

Abstract Juvenile chinook salmon were sampled from August 1986 to March 1987 at stations near Prince George and Quesnel, influenced by sewage and pulp mill discharges. Maximum densities of 0.2 fish·mࢤ2 were recorded. Salmon were collected at reference sites in November 1986 and at Agassiz in April 1987. Fingerling chinook were exposed at 0.7°C to a commercial wood preservative containing 2,3,4,6 - tetrachlorophenol (TeCP) and pentachlorophenol (PCP) in the laboratory to simulate winter conditions in the upper Fraser River. Fish exposed for 62 days to 2 ug·Lࢤ1 contained a mean of 224 ng·gࢤ1 TeCP and 431 ng·gࢤ1 PCP. Chlorophenol uptake in feral fish was low. However, 3,4,5-trichloro-guaiacol levels to 304 ng·gࢤ1 and tetrachloroguaiacol values to 136 ng·gࢤ1 were measured in March. Fish from Agassiz, 518 km downstream of Quesnel, also contained these two substances. Thus chinook salmon can bioconcentrate persistent chlorophenols and chloroguaiacols directly from cold water (< 1°C). The biological consequences are uncertain.

Cytochrome P450 1A and related measurements in juvenile chinook salmon (Oncorhynchus tshawytscha) from the Fraser River

2000 ◽  
Vol 57 (2) ◽  
pp. 405-413 ◽  
Author(s):  
J Y Wilson ◽  
R F Addison ◽  
D Martens ◽  
R Gordon ◽  
B Glickman
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Erod Activity ◽  
Dna Adduct ◽  
Clear Correlation ◽  
Fraser River ◽  
Juvenile Chinook Salmon ◽  
Liver Histopathology ◽  
Polycyclic Aromatic ◽  
Juvenile Chinook

Juvenile chinook salmon (Oncorhynchus tshawytscha) were captured at six sites on the upper Fraser, Nechako, and Thompson rivers, British Columbia, Canada. Biological responses were measured in the liver to assess the effects of contaminants on the fish before they began migration downstream. Both ethoxyresorufin-O-deethylase (EROD) activity and CYP 1A concentrations were significantly enhanced, being two- to three-fold higher in Fraser River samples compared with those fish from reference sites on the Nechako River. DNA adduct concentrations were two- to four-fold higher in Fraser River fish, although liver histopathology appeared unaffected. Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) in the carcasses contributed to total contaminant burdens of less than 1 pg·g-1. Polycyclic aromatic hydrocarbon (PAH) metabolites were undetectable in nearly all samples of bile. There were strong correlations between EROD activity, CYP 1A induction, and DNA adduct concentrations but no clear correlation between these responses and PCDD, PCDF, or PCB concentrations.

A Record of Pacific Herring (Clupea harengus pallasi) Feeding on Juvenile Chinook Salmon (Oncorhynchus tshawytscha) in a British Columbia Estuary

1971 ◽  
Vol 28 (12) ◽  
pp. 1921-1921 ◽  
Author(s):  
Jun Ito ◽  
R. R. Parker
Keyword(s):  
British Columbia ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Clupea Harengus ◽  
Pacific Herring ◽  
Predator Prey ◽  
Juvenile Chinook Salmon ◽  
Clupea Harengus Pallasi ◽  
Juvenile Chinook

An occurrence of Pacific herring (Clupea harengus pallasi) predation on juvenile chinook salmon (Oncorhynchus tshawytscha) is described. This is the first recorded incidence of this particular predator–prey relation.

Comparative resistance of Oregon (Big Creek) and British Columbia (Capilano) juvenile chinook salmon to the myxozoan pathogen, Ceratomyxa shasta, after laboratory exposure to Fraser River water

1984 ◽  
Vol 62 (7) ◽  
pp. 1423-1424 ◽  
Author(s):  
Hilda Lei Ching
Keyword(s):  
British Columbia ◽  
River Water ◽  
High Resistance ◽  
Chinook Salmon ◽  
Juvenile Fish ◽  
Fraser River ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook ◽  
Infectious Stage ◽  
Laboratory Exposure

In a laboratory experiment conducted in the fall 1983, Oregon (Big Creek) and British Columbia (Capilano) hatchery Chinook salmon were exposed to Fraser River water containing the infectious stage of the myxozoan pathogen, Ceratomyxa shasta. The juvenile fish were exposed for 10 days in 370 L of water (74 L replaced every other day for 5 days). While only 1 of 21 Big Creek fish became infected, all 20 of the Capilano fish died of C. shasta within 40 days. The Big Creek fish demonstrated high resistance to the parasite while the Capilano fish had low resistance. These results were similar to those from field exposures in previous studies.

Sign in / Sign up

Export Citation Format

Share Document