Migratory patterns of sockeye salmon (Oncorhynchus nerka) smolts in the Strait of Georgia, British Columbia, as determined by analysis of parasite assemblages

1989 ◽  
Vol 67 (7) ◽  
pp. 1670-1678 ◽  
Author(s):  
C. Groot ◽  
R. E. Bailey ◽  
L. Margolis ◽  
K. Cooke
Keyword(s):  
Sockeye Salmon ◽  
River Estuary ◽  
River System ◽  
Fraser River ◽  
Strait Of Georgia ◽  
The Pacific ◽  
Lake Washington ◽  
Migratory Routes ◽  
Migratory Patterns ◽  
Parasite Assemblages

Sockeye salmon smolts from the Fraser River system, migrating northward through the Strait of Georgia towards the Pacific Ocean, follow either an eastern route by immediately travelling northward upon leaving the Fraser River estuary or a western route by first crossing the Strait of Georgia towards Vancouver Island and then moving northward diagonally across the Strait of Georgia to join smolts migrating along the mainland shore. We used variations in parasite assemblages among Fraser River and Lake Washington sockeye smolt stocks and a maximum-likelihood mixture model to estimate the stock composition of the smolts along the two migratory routes. The results showed that most Fraser River sockeye smolts migrate northward via both the eastern and western routes through the Strait of Georgia, indicating that there is no stock specific route selection. Lake Washington smolts were more prevalent along the western route and we suggest that these smolts are transported westward when attempting to cross the Fraser River plume.

Estimating Stock Composition of Migrating Juvenile Fraser River (British Columbia) Sockeye Salmon, Oncorhynchus nerka, Using Parasites as Natural Tags

1988 ◽  
Vol 45 (4) ◽  
pp. 586-591 ◽  
Author(s):  
R. E. Bailey ◽  
L. Margolis ◽  
C. Groot
Keyword(s):  
British Columbia ◽  
Maximum Likelihood ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Fraser River ◽  
Dominant Group ◽  
Strait Of Georgia ◽  
Natural Tags ◽  
Lake Washington ◽  
The Individual

Simulated mixtures of juvenile sockeye salmon (Oncorhynchus nerka) were constructed using parasite data to represent proportionally the major component stocks of Fraser River and Lake Washington sockeye migrating within the Strait of Georgia, British Columbia, in 1982–84. Samples of migrating juveniles were also collected from Bedwell Harbour, South Pender Island, British Columbia, each year and analyzed for parasites and stock composition. The compositions of simulated and sample mixtures were estimated using a maximum likelihood stock composition model. Simulated mixture compositions were accurately estimated for most stocks for all year-classes. When significant misassignment occurred between stocks, the stocks were analyzed as a complex using the allocate-sum procedure. Sample mixture estimates correctly identified the dominant stock for each year-class, although for 1984 the dominant group was determined as a complex of three stocks because the individual stocks were not distinguishable. The results indicate that it is feasible to use parasites as natural tags to estimate stock compositions of migrating juvenile sockeye salmon in the Strait of Georgia.

A reappraisal of the ocean migration patterns of Fraser River sockeye salmon (Oncorhynchus nerka) by individual-based modelling

1997 ◽  
Vol 54 (4) ◽  
pp. 847-858 ◽  
Author(s):  
E E Walter ◽  
J P Scandol ◽  
M C Healey
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
River System ◽  
Spatially Explicit ◽  
Fraser River ◽  
Directional Bias ◽  
Migration Patterns ◽  
Ocean Surface Currents ◽  
Adult Body Weight ◽  
Migratory Patterns

Although sockeye salmon (Oncorhynchus nerka) spend 1-4 years in the ocean and accumulate 99% of adult body weight during this period, their migratory patterns in the Northeast Pacific are not yet well understood. A model of ocean migration based on conjecture from limited catch and tagging data has influenced work in sockeye ecology for the past 20 years. To evaluate this model, we constructed a spatially explicit individual-based model that used ocean surface currents and simple behavioural rules to simulate migration patterns for sockeye from the Fraser River system. We explored several modelled behaviours, including random swimming and swimming with a directional bias during some months. The simulations begin at the time when juveniles leave inside coastal waters and end when return migration begins (a few months before river reentry). We determined that simple undirected swimming for most of the ocean phase (except the first 4 months when smolts are near the coast) provided results that challenged the prevailing model but did not require complex assumptions. The migration patterns generated by these rules compare well both qualitatively and quantitatively with the existing empirical data on British Columbia sockeye distribution and migrations in the ocean.

Quantifying survival of age-2 Chilko Lake sockeye salmon during the first 50 days of migration

2019 ◽  
Vol 76 (1) ◽  
pp. 136-152 ◽  
Author(s):  
Erin L. Rechisky ◽  
Aswea D. Porter ◽  
Timothy D. Clark ◽  
Nathan B. Furey ◽  
Marika Kirstin Gale ◽  
...  
Keyword(s):  
Acoustic Telemetry ◽  
Sockeye Salmon ◽  
Detection Efficiency ◽  
River Estuary ◽  
Downstream Migration ◽  
Survival Models ◽  
Fraser River ◽  
Strait Of Georgia ◽  
Individual Covariates ◽  
Body Size Effect

We used acoustic telemetry to investigate survival of age-2 sockeye salmon (Oncorhynchus nerka) as they emigrated from Chilko Lake, British Columbia, Canada, to northeastern Vancouver Island (NEVI) from 2010 to 2014. We built on our previously reported results by including an additional year of data and by converting survival estimates into rates (distance and time) to compare across disproportionate habitats. We also refined our survival estimates by including individual covariates in our survival models and by re-investigating the detection efficiency of the final detection site. There was a tag burden effect in 2012 and a body size effect in 2013. Excluding 2010, survival during the 35- to 47-day migration to NEVI (range of annual mean travel time; 1044 km) ranged between 8% and 14%. Weekly survival rate (S·week−1) during downstream migration to the Fraser River estuary, through the central Strait of Georgia (CSOG), and NEVI was 25%–46%, 75%–90%, and 34%–64%, respectively. In addition to marked losses in freshwater tributaries, sockeye also experienced high losses north of the CSOG consistent with earlier results for Cultus Lake sockeye.

Pollution in the Strait of Georgia: a Review

1983 ◽  
Vol 40 (7) ◽  
pp. 1142-1167 ◽  
Author(s):  
Michael Waldichuk
Keyword(s):  
Urban Communities ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
River Estuary ◽  
Oxygen Depletion ◽  
Fraser River ◽  
Pulp Mills ◽  
Strait Of Georgia ◽  
Spring Freshet

The Strait of Georgia, when considered as a whole, is still comparatively free of major pollution problems. Local environmental degradation has taken place, however, in waters on the periphery of the Strait, adjacent to urban communities and industries, such as pulp mills. The Fraser River, which is the major source of freshwater to the Strait, introduces natural and man-made materials that can adversely affect its estuary and the marine environment. The Strait of Georgia is flushed regularly, with deep waters being replaced about annually and waters in the upper layer having a considerably shorter residence time. Buildup of pollutants or their effects, e.g. oxygen depletion, are prevented in this way. However, there is refluxing of surface waters into the deep zone from the mixing region at the southern entrance to the Strait, and this means that surface pollutants such as oil could pollute the deep water and be retained there for up to a year. Problems affecting fisheries have been identified at the Fraser River Estuary arising from discharge of sewage treatment plant effluent. The major problem of pollution affecting fisheries in the Strait of Georgia has been bacteriological contamination from sewage, which has necessitated the closure of shellfish beds. The quality of oysters, as represented by condition factor and flavor, has deteriorated in the vicinity of some pulp mills. Evidence so far indicates that the "critical pollutants," e.g. petroleum hydrocarbons, organochlorines, and metals, which are persistent, toxic, and can be bioaccumulated by marine organisms, are present in low concentrations in the water, sediments, and biota away from the Fraser River Estuary. Wood wastes in the Strait of Georgia create a menace to navigation, especially during the spring freshet of the Fraser River.

Drift Bottle Observations in the Strait of Georgia

1958 ◽  
Vol 15 (5) ◽  
pp. 1065-1102 ◽  
Author(s):  
Michael Waldichuk
Keyword(s):  
Surface Water ◽  
River Estuary ◽  
Surface Current ◽  
Fraser River ◽  
Strait Of Georgia ◽  
Average Speed ◽  
Local Areas ◽  
Strong Surface ◽  
Gulf Islands ◽  
Western Side

Drift bottle observations were carried out in the Strait of Georgia during the summers of 1926–1929. A total of 1,636 bottles was released of which 672 were recovered, giving an over-all return of 41%.No consistent pattern of drift in the strait as a whole could be clearly drawn from the recoveries. Some consistency of circulation in local areas can be inferred from the net drift of bottles.Winds dominated drift bottle movements in the open strait, where tidal currents are weak. A general northwestward drift was noted from releases along the eastern side of the strait and a southeastward drift along the western side. This suggests a large counterclockwise circulation of surface water over the whole strait. A smaller gyral circulating in the same direction is apparent in the southern strait, south of a line from Sand Heads to Active Pass.A strong surface current is directed from the Fraser River estuary across the strait to the passes among the Gulf Islands. This seaward flow of fresh water is augmented by a strong seaward tidal current during large ebb tides.Tidal currents are strong with definite periodicities in the channels bordering the strait. Current speeds of more than 26 cm./sec. (0.5 knot) were calculated from data on drift bottles whose drift was of brief duration. Average speed of drift was about 10 cm./sec. (0.2 knot).

Factors Affecting Sockeye Salmon (Oncorhynchus nerka) Growth in Four Lakes of the Fraser River System

1974 ◽  
Vol 31 (5) ◽  
pp. 871-892 ◽  
Author(s):  
J. C. Goodlad ◽  
T. W. Gjernes ◽  
E. L. Brannon
Keyword(s):  
Population Density ◽  
Standing Crop ◽  
Sockeye Salmon ◽  
River System ◽  
Growing Season ◽  
High Elevation ◽  
Zooplankton Abundance ◽  
Fraser River ◽  
Factors Affecting ◽  
Short Growing Season

Analysis of data from four sockeye rearing lakes of the Fraser River system for periods of up to 20 yr provided information on the relation of estimated fish density (female spawners/ha), temperature, and zooplankton standing crops to growth. The lakes differed widely in all attributes. Growth was inversely related to estimated population density in three of the lakes, but wide variations in growth at low density occurred in the fourth, a cold lake at high elevation with short growing season. In this lake, and to a lesser extent in another lake with short growing season, temperature during fry emergence and early lake residence accounted for much of the recorded fluctuation in growth. Reduced zooplankton abundance was associated with high sockeye density in two of the lakes with intermediate standing crops and greatest sockeye densities, but was not recorded in a lake of low standing crop and intermediate sockeye density. Sockeye feeding was found to be highly selective in one lake, and a limited proportion of the zooplankton standing crop was utilized. It is suggested that reduction in standing crop by grazing of juvenile sockeye, and associated decrease in growth, is greatest as the large zooplankters are progressively reduced in abundance. Further reduction in standing crop and in sockeye growth was suggested to proceed at a slower rate. Competition at high population density was concluded to be the factor most responsible for reducing sockeye growth.

scholarly journals Recent experience of surveying the spawning grounds of pacific salmons in the water bodies of Chukotka

2020 ◽  
Vol 200 (2) ◽  
pp. 270-291
Author(s):  
E. A. Shevlyakov ◽  
S. V. Shubkin
Keyword(s):  
Sockeye Salmon ◽  
Pacific Salmon ◽  
Pink Salmon ◽  
River System ◽  
Aerial Survey ◽  
Water Bodies ◽  
Recent Experience ◽  
Spawning Grounds ◽  
The Pacific ◽  
First Time

Aerial survey of the pacific salmon spawning grounds was conducted in the water bodies of Chukotka belonged to the Bering Sea basin (the Anadyr, Velikaya, Tumanskaya Rivers and Meinypilgyno lake-river system) in 2019, for the first time since 1992. Total flight time was 35 hours, approximate length of the transects was 3,800 km. Number of the spawners was estimated as 660.7 . 103 ind. for chum salmon, 112.2 . 103 ind. for sockeye salmon, and 3678.0 . 103 ind. for pink salmon, features of their distribution are described.

Anomalous Occurrence of Carp (Cyprinus carpio) in the Marine Environment

1971 ◽  
Vol 28 (9) ◽  
pp. 1345-1347 ◽  
Author(s):  
W. E. Barraclough ◽  
D. G. Robinson
Keyword(s):  
British Columbia ◽  
Marine Environment ◽  
Surface Waters ◽  
Cyprinus Carpio ◽  
River Estuary ◽  
Vancouver Island ◽  
Fraser River ◽  
Strait Of Georgia ◽  
Low Salinity ◽  
Carp Cyprinus Carpio

Juvenile carp (Cyprinus carpio) were caught with a surface trawl in low salinity surface waters of the Strait of Georgia, British Columbia, during July 1967. A natural environmental route is established for the possible movement of carp from the Fraser River estuary to watersheds on Vancouver Island.

Mercury Content of Spiny Dogfish (Squalus acanthias) in the Strait of Georgia, British Columbia

1972 ◽  
Vol 29 (10) ◽  
pp. 1487-1490 ◽  
Author(s):  
C. R. Forrester ◽  
K. S. Ketchen ◽  
C. C. Wong
Keyword(s):  
Total Mercury ◽  
River Estuary ◽  
Mercury Content ◽  
Squalus Acanthias ◽  
Spiny Dogfish ◽  
Fraser River ◽  
Female Fish ◽  
Male And Female ◽  
Strait Of Georgia ◽  
Total Length

Total mercury content of Squalus acanthias sampled in the Strait of Georgia reached levels of 0.5 ppm at fish lengths of 72 and 77 cm for male and female fish, respectively. For any given length above 65 cm the mercury content was higher among males than females and higher in samples taken off the Fraser River Estuary than in other areas of the Strait. Levels of mercury reached 1.7 ppm in males (to 95 cm in total length) and almost 2.0 ppm in females (to 120 cm in total length).

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