Estimation of Sea Mortality Rates for the 1961 Brood-Year Pink Salmon of the Bella Coola Area, British Columbia

1965 ◽  
Vol 22 (6) ◽  
pp. 1523-1554 ◽  
Author(s):  
Robert R. Parker
Keyword(s):  
British Columbia ◽  
Pink Salmon ◽  
Mortality Rates ◽  
Disproportionate Representation ◽  
Natural Mortality ◽  
Marine Waters ◽  
Two Stage ◽  
Short Period ◽  
Seaward Migration ◽  
Bella Coola

A two-stage marking experiment was designed to estimate natural mortality rates of pink salmon during their early (coastal) and later (oceanic) periods of sea life. Difficulty was encountered because of disproportionate representation of various stocks in the marked populations, the stocks being subject to dissimilar rates of exploitation. Several assumptions were made for which the error introduced could not be fully evaluated. Under these assumptions, the results indicate (approximate values) that 55.7 million fry, resulting from the 1961 Burke Channel–Bella Coola stocks brood year, entered the sea. Of these, 77% died during the initial 40-day period of life in the enclosed marine waters. The following stage, from the time of seaward migration to adult return, a period of about 410 days, 78% of the remaining population died. The adult return was subjected to a rate of exploitation of 0.85 which produced a catch of 2.5 million fish. The spawning escapement was approximately 450,000 fish. It is established that the rate of natural mortality during the initial short period was much more severe than that during the remaining period of sea life.

Estimation of Sea Mortality Rates for the 1960 Brood-Year Pink Salmon of Hook Nose Creek, British Columbia

1964 ◽  
Vol 21 (5) ◽  
pp. 1019-1034 ◽  
Author(s):  
Robert R. Parker
Keyword(s):  
British Columbia ◽  
Mortality Rate ◽  
Marine Environment ◽  
Pink Salmon ◽  
Mortality Rates ◽  
Natural Mortality ◽  
Two Stage ◽  
Fishing Season ◽  
Salmon Fry ◽  
Bella Coola

Seaward migrating pink salmon fry at Hook Nose Creek, British Columbia, were estimated to total 1,153,000 in 1961. Of these, 41.5% or 479,000, were marked by amputation of both ventral fins (BV). Following this marking 36,900 fingerling were captured in the marine environment and marked by removal of the adipose and right ventral fins (ARV). During the 1962 fishing season 1,160,645 adult pinks were examined and 7050 BV and 184 ARV marks recognized. For the Hook Nose Creek stock, survival at sea from natural causes is shown to approximate 22% and the rate of exploitation was 95%. This stock is shown to be more exposed to fishing than the Bella Coola stock, for which a rate of exploitation of 69–80% is estimated. Rate of exploitation for Dean Channel stocks is even lower. These differences are explained as due to times of entry and rates of travel through the fishery. The two-stage marking experiment failed to estimate the natural mortality rate of juvenile pinks during the initial 5 weeks of sea life because of this dissimilarity between rates of exploitation on the stocks in the area.

Marine Mortality Schedules of Pink Salmon of the Bella Coola River, Central British Columbia

1968 ◽  
Vol 25 (4) ◽  
pp. 757-794 ◽  
Author(s):  
Robert R. Parker
Keyword(s):  
Mortality Rate ◽  
Early Life ◽  
Pink Salmon ◽  
Mortality Rates ◽  
Early Mortality ◽  
Initial Population ◽  
Natural Mortality ◽  
Time Period ◽  
Marking Technique ◽  
Bella Coola

The hypothesis that natural mortality rates of pink salmon during early life are generally much larger than during the later period has been tested for 3 brood-years of the Bella Coola River stock using a two-stage marking technique. Average daily losses to the population during the first 40 days are estimated to vary between 2 and 4%, and for the later 410-day period between 0.4 and 0.8%. These rates produce losses amounting to between 59 and 77% of the initial population during the first 40 days. Of the population surviving at 40 days, further losses of between 78 and 95% occurred. The latter losses are considered to be maximum estimates because of bias introduced by catches of unknown magnitude. Thus, although the early mortality is exceeded by the later, the time period is approximately 10 times as long, and the intensity of the mortality rate is much higher during early sea life.

Orientation of Pink Salmon (Oncorhynchus gorbuscha) During Early Marine Migration from Bella Coola River System

1967 ◽  
Vol 24 (11) ◽  
pp. 2321-2338 ◽  
Author(s):  
M. C. Healey
Keyword(s):  
British Columbia ◽  
Pink Salmon ◽  
River System ◽  
Early Morning ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Salmon Fry ◽  
Marine Migration ◽  
Bella Coola

During May and June 1966, the migration of pink salmon fry from the Bella Coola River was studied in Burke Channel, British Columbia. The movement of pink fry down Burke Channel was saltatory. Short periods of active migration were interspersed with longer periods when the fry did not migrate and accumulated in bays. Fry were sampled from these accumulations and their ability to orient using celestial cues was examined. During the early morning, fry tended to prefer directions at right angles to their direction of migration, but at other times of the day preferred the direction of migration. The preference for the direction of migration was strongest at midday. Fry were better oriented on clear days than on cloudy days. These data indicate that fry may use celestial cues to find directions during their oceanic migrations.

DESCRIPTION OF GENOLINEA ONCORHYNCHI N. SP. (TREMATODA: HEMIURIDAE) FROM ONCORHYNCHUS GORBUSCHA IN BRITISH COLUMBIA WITH NOTES ON THE GENUS

1956 ◽  
Vol 34 (6) ◽  
pp. 573-577
Author(s):  
L. Margolis ◽  
James R Adams
Keyword(s):  
British Columbia ◽  
Geographical Distribution ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Marine Waters

Genolinea oncorhynchi n. sp., parasitic in the stomach of Oncorhynchus gorbuscha (pink salmon) from British Columbia marine waters, is described and compared with other known members of Genolinea. Notes on host and geographical distribution of the genus are presented.

Parasite Fauna of Pink Salmon (Oncorhynchus gorbuscha) of the Bella Coola River, Central British Columbia, During Their Early Sea Life

1969 ◽  
Vol 26 (4) ◽  
pp. 813-820 ◽  
Author(s):  
Norbert P. J. Boyce
Keyword(s):  
British Columbia ◽  
Initial Phase ◽  
Pink Salmon ◽  
Parasite Fauna ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Marine Life ◽  
Predominant Species ◽  
Bella Coola

The acquisition of parasites by pink salmon during their initial phase of marine life is described. The parasites found were the trematodes Lecithaster gibbosus, Parahemiurus merus, and Pentagramma petrowi, the cestode Phyllobothrium sp. larva, and the nematode Contracaecum sp. larva. An attempt is made to account for the occurrence of the more predominant species, particularly the trematode L. gibbosus.

Age-specific natural mortality rates of adult Pacific herring (Clupea pallasi) from southern British Columbia

2000 ◽  
Vol 57 (11) ◽  
pp. 2258-2266 ◽  
Author(s):  
R W Tanasichuk
Keyword(s):  
British Columbia ◽  
Mortality Rate ◽  
Sampling Bias ◽  
Mortality Rates ◽  
Energy Requirements ◽  
Pacific Herring ◽  
Natural Mortality ◽  
Clupea Pallasi ◽  
Surplus Energy ◽  
Using Data

I used data for over 665 000 Pacific herring (Clupea pallasi) seined or gillnetted in southern British Columbia between 1951 and 1998 to estimate age- and year-specific adult natural mortality rates. Apparent sampling bias precluded using data collected before 1980. The instantaneous natural mortality rate is an increasing exponential function of age. Surplus energy requirements for gonad recrudescence appear to cause the death of adult herring.

scholarly journals Physiological resilience of pink salmon to naturally occurring ocean acidification

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Andrea Y Frommel ◽  
Justin Carless ◽  
Brian P V Hunt ◽  
Colin J Brauner
Keyword(s):  
British Columbia ◽  
Elevated Co2 ◽  
Condition Factor ◽  
Pacific Salmon ◽  
Pink Salmon ◽  
Hypoxia Tolerance ◽  
High Co2 ◽  
The North ◽  
Naturally Occurring ◽  
Co2 Levels

Abstract Pacific salmon stocks are in decline with climate change named as a contributing factor. The North Pacific coast of British Columbia is characterized by strong temporal and spatial heterogeneity in ocean conditions with upwelling events elevating CO2 levels up to 10-fold those of pre-industrial global averages. Early life stages of pink salmon have been shown to be affected by these CO2 levels, and juveniles naturally migrate through regions of high CO2 during the energetically costly phase of smoltification. To investigate the physiological response of out-migrating wild juvenile pink salmon to these naturally occurring elevated CO2 levels, we captured fish in Georgia Strait, British Columbia and transported them to a marine lab (Hakai Institute, Quadra Island) where fish were exposed to one of three CO2 levels (850, 1500 and 2000 μatm CO2) for 2 weeks. At ½, 1 and 2 weeks of exposure, we measured their weight and length to calculate condition factor (Fulton’s K), as well as haematocrit and plasma [Cl−]. At each of these times, two additional stressors were imposed (hypoxia and temperature) to provide further insight into their physiological condition. Juvenile pink salmon were largely robust to elevated CO2 concentrations up to 2000 μatm CO2, with no mortality or change in condition factor over the 2-week exposure duration. After 1 week of exposure, temperature and hypoxia tolerance were significantly reduced in high CO2, an effect that did not persist to 2 weeks of exposure. Haematocrit was increased by 20% after 2 weeks in the CO2 treatments relative to the initial measurements, while plasma [Cl−] was not significantly different. Taken together, these data indicate that juvenile pink salmon are quite resilient to naturally occurring high CO2 levels during their ocean outmigration.

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