scholarly journals Gulls, Larus spp., Foraging at Pink Salmon, Oncorhynchus gorbuscha, Spawning Runs

2004 ◽  
Vol 118 (3) ◽  
pp. 442
Author(s):  
Mary F. Willson
Keyword(s):  
Body Size ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Dominance Status ◽  
Southeast Alaska ◽  
Physical Strength ◽  
Salmon Eggs ◽  
Foraging Experience ◽  
Salmon Carcasses

Small and immature gulls foraged more often on drifting salmon eggs than did large and mature gulls, and large and mature gulls foraged more often on salmon carcasses, at streams in Southeast Alaska. These differences may be related to body size via physical strength and dominance status, as well as foraging experience.

Resolving allegations of oil damage to incubating pink salmon eggs in Prince William Sound

2001 ◽  
Vol 58 (6) ◽  
pp. 1070-1076 ◽  
Author(s):  
Ernest L Brannon ◽  
Keya CM Collins ◽  
Lawrence L Moulton ◽  
Keith R Parker
Keyword(s):  
Oil Spill ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Sensitive Period ◽  
Time Sampling ◽  
Prince William Sound ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Salmon Eggs ◽  
Original Survey ◽  
Oil Exposure

The Exxon Valdez Oil Spill Trustee Council concluded that oil caused mortality of pink salmon (Oncorhynchus gorbuscha) eggs in Prince William Sound streams. Their conclusion was based primarily on Alaska Department of Fish and Game (ADF&G) studies which reported that mean mortality of embryos in eggs was higher in oiled than non-oiled streams when sampled shortly after spawning completion. However, developing embryos are vulnerable to shock mortality for a period of 20 days after fertilization, and the embryos in eggs from the latest spawners were still in the sensitive period at the time sampling took place. We argue that the original ADF&G analysis should have included sample timing in statistical comparisons of mortality between streams. Analysis of a subset of the ADF&G data showed that sampling shock was a major source of embryo mortality in these samples, and that source of mortality in the original survey would likely have been mistakenly interpreted as an oiling effect. Compensating for sample timing removed all statistical evidence for an oiling effect in the data subset. We conclude that the ADF&G study design confounded the ability to assess for the effect of oil exposure on pink salmon eggs.

Possible Effects of the Sitka Eddy on Sockeye (Oncorhynchus nerka) and Pink Salmon (Oncorhynchus gorbuscha) Migration off Southeast Alaska

1986 ◽  
Vol 43 (2) ◽  
pp. 498-504 ◽  
Author(s):  
Kevin Hamilton ◽  
Lawrence A. Mysak
Keyword(s):  
Oncorhynchus Nerka ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Surface Currents ◽  
Oceanic Circulation ◽  
Migration Routes ◽  
Southeast Alaska ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Northeast Pacific ◽  
Northeast Pacific Ocean

The interannual variability of sockeye (Oncorhynchus nerka) and pink salmon (Oncorhynchus gorbuscha) catches during 1952–62 from southeast Alaska and northern British Columbia is examined in relation to the appearance and disappearance of the Sitka eddy in the offshore oceanic circulation. In years when this large (~300 km in diameter) and intense (surface currents ~0.5 m/s) vortex is present, the spawning migration routes of salmon returning to the Nass and Skeena rivers tend to be deflected southward. An analysis of salmon tagging data collected during 1957 (when the eddy was absent) and 1958 (when the eddy was present) supports this conclusion. The southward deflection during 1958 is a particularly interesting result in light of many other observations which show that several fish species were displaced northward during the 1958 warming of the northeast Pacific Ocean.

Results for Three Generations from Transfers of Pink Salmon (Oncorhynchus gorbuscha) Spawn to the Qualicum River in 1963 and 1964

1971 ◽  
Vol 28 (5) ◽  
pp. 647-654 ◽  
Author(s):  
C. E. Walker ◽  
D. B. Lister
Keyword(s):  
Chum Salmon ◽  
Pink Salmon ◽  
Stream Temperature ◽  
Rate Of Return ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Three Generations ◽  
Salmon Eggs ◽  
Bear River

Transfers of pink salmon (Oncorhynchus gorbuscha) eggs were made to the Qualicum River in two years, utilizing 5.79 million eggs from Cheakamus River stock in 1963 and 6.85 million eggs from Bear River stock in 1964. Adult returns to the Qualicum River were 100 spawners in 1965, 1967, and 1969; 11,940 in 1966; 3000 in 1968; and 300 in 1970. Differences between the odd- and even-year plants were noted in times of egg-take (equivalent to time of spawning of donor stock), incubation, and fry emigration, lengths of emigrating fry, possibility of losses through predation by herring on estuarine fry, and direction of orientation to the recipient (Qualicum River) stream. Pronounced differences between donor stock in rate of return are thought to be primarily related to differences in spawning times and stream temperature. The decrease in numbers of adults in the even-year generation may have been due to lower freshwater survival during incubation as a result of suspected superimposition of chum salmon on the earlier deposited pink salmon eggs; the loss was estimated to be in the order of 46%.

Consumption and distribution of salmon (Oncorhynchus spp.) nutrients and energy by terrestrial flies

2006 ◽  
Vol 63 (9) ◽  
pp. 2076-2086 ◽  
Author(s):  
Morgan D Hocking ◽  
Thomas E Reimchen
Keyword(s):  
Chum Salmon ◽  
Pacific Salmon ◽  
Pink Salmon ◽  
Isotope Analysis ◽  
Terrestrial Ecosystems ◽  
Oncorhynchus Gorbuscha ◽  
Oncorhynchus Keta ◽  
The North ◽  
Terrestrial Habitats ◽  
Salmon Carcasses

Anadromous Pacific salmon (Oncorhynchus spp.) subsidize terrestrial food webs with their nutrients and carcasses, a process driven largely by selective foraging by bears (Ursus spp.). We quantify wildlife transfer of salmon carcasses to riparian zones on two watersheds in coastal British Columbia and estimate total terrestrial fly production from remnant carcasses. Large-bodied chum salmon (Oncorhynchus keta) were transferred into the forest at a greater rate than were pink salmon (Oncorhynchus gorbuscha) (chum salmon mass = 6089–11 031 kg, 16%–48% of salmon run; pink salmon mass = 2266–2808 kg, 4%–6% of salmon run). Blow flies (genus Calliphora) and other Diptera dominated colonization (>90% of salmon carcasses). Between the two watersheds, 196 and 265 g of Calliphora larvae per metre of spawning length (4 and 7 million larvae for whole watersheds) were generated from salmon carcass transfer. Stable isotope analysis of δ15N and δ13C of spring-emerging adult Calliphora revealed that >80% of individuals had salmon-based signatures. Flies are a dominant consumer and vector of salmon nutrients in terrestrial habitats and supplement the diet of at least 16 vertebrate and 22 invertebrate species. Anticipated further declines of salmon in the North Pacific can be expected to further erode the complex associations coupling marine and terrestrial ecosystems.

Variations in Annual Average Weights of British Columbia Pink Salmon, 1944–1958

1959 ◽  
Vol 16 (3) ◽  
pp. 329-337 ◽  
Author(s):  
Harold Godfrey
Keyword(s):  
British Columbia ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Steady Increase ◽  
Average Weight ◽  
Weight Changes ◽  
Southeast Alaska ◽  
Annual Changes ◽  
Average Size ◽  
Weight Data

Average weight data of British Columbia pink salmon, Oncorhynchus gorbuscha, since 1944 were made available by the Fisheries Association of British Columbia, and were used to compare annual changes in size among stocks throughout the Province. Adult pinks of the odd-year cycle were almost invariably larger than those of the even-year cycle. In British Columbia this cycle has also been consistently the more abundant, and in southeast Alaska these fish have been either about equally as numerous as the even-year pinks, or, upon occasion, much more numerous. The pink salmon of each of the major fishing areas in the Province show similar annual changes in average weight. From an extremely small average size in 1946 there was a trend of steady increase, among all stocks and involving both cycles, over the next 8 years; this was followed by a decline in 1955 and 1956, then a further increase in 1957 and 1958. A comparison between southeastern Alaska pinks and pinks of northern British Columbia showed that they had experienced similar year-to-year weight changes during the earlier period of 1930–1939.

Influence of salmon spawner densities on stream productivity in Southeast Alaska

1999 ◽  
Vol 56 (9) ◽  
pp. 1600-1611 ◽  
Author(s):  
Mark S Wipfli ◽  
John P Hudson ◽  
Dominic T Chaloner ◽  
John P Caouette
Keyword(s):  
Chlorophyll A ◽  
Pink Salmon ◽  
Dry Mass ◽  
Trophic Levels ◽  
Oncorhynchus Gorbuscha ◽  
Southeast Alaska ◽  
Natural Stream ◽  
Forest Stream ◽  
Natural Streams ◽  
Freshwater Salmon

We conducted this study to determine the relationship between salmon spawner abundance and stream biofilm and benthic macroinvertebrate abundance in Southeast Alaska. Experiments took place in outdoor artificial and natural streams. Six pink salmon (Oncorhynchus gorbuscha) carcass treatments (0.00, 1.45, 2.90, 4.35, 5.80, and 7.25 kg wet mass) placed in artificial channels were subsampled repeatedly for biofilm ash-free dry mass (AFDM), chlorophyll a, and macroinvertebrates. In a small (nonanadromous) forest stream, we sampled benthos throughout a 66-m reach 17 days after distributing 60 carcasses along the lower half of that reach. All response variables significantly increased in response to carcass additions in both artificial and natural streams. Chlorophyll a continued to increase across all loading rates, while AFDM and total macroinvertebrate densities showed no further response to loading beyond the first treatment (1.45 kg) in artificial streams. In the natural stream, AFDM and chironomid densities continued increasing across loading levels. These results indicated that increased spawner densities increased lower trophic level abundance until a trophic capacity was reached. Salmon escapement goals should consider food web effects, especially on trophic levels that support juvenile salmonids, that ultimately affect freshwater salmon production.

Epizootics of thyroid hyperplasia in Lake Superior and Lake Erie pink salmon (Oncorhynchus gorbuscha (Walbaum))

1988 ◽  
Vol 66 (12) ◽  
pp. 2676-2687 ◽  
Author(s):  
Douglas B. Noltie ◽  
John F. Leatherland ◽  
Miles H. A. Keenleyside
Keyword(s):  
British Columbia ◽  
Body Size ◽  
Great Lakes ◽  
Lake Erie ◽  
Lake Superior ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Negative Effects ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Thyroid Hyperplasia

All Lake Superior and Lake Erie pink salmon (Oncorhynchus gorbuscha (Walbaum)) collected exhibited thyroid hyperplasia. Samples from British Columbia, however, were unaffected. In fish from Lake Superior, lesion sizes increased through a graded series and were correlated with increased body size. In contrast, almost all Lake Erie fish exhibited extreme hyperplasia regardless of body size. Pink salmon lesion histopathology differed markedly from that shown by Great Lakes coho (Oncorhynchus kisutch (Walbaum)) and chinook (Oncorhynchus ishawytscha (Walbaum)) salmon. Among Great Lakes populations, males and females were equally afflicted. Greater proportions of females entered their spawning streams with immature gonads in Lake Erie, where fish exhibited larger lesions. Indications are that males showed poorer secondary sexual character development there as well. Gonad weights in Lake Erie males were proportionally smaller than in Lake Superior males, and liver weights in Lake Superior fish were smaller than in British Columbia specimens. Thyroid hormone levels and lesion sizes were negatively correlated, providing evidence of hypothyroidism. These findings warn of potential water quality problems in Lake Superior, and suggest a useful means of assessing the goitrogenic potential of Great Lakes systems. Despite its negative effects, however, thyroid hyperplasia has not prevented the increase of pink salmon numbers and distribution in the Great Lakes.

A genetic analysis of body size in pink salmon (Oncorhynchus gorbuscha)

Genome ◽  
1988 ◽  
Vol 30 (1) ◽  
pp. 31-35 ◽  
Author(s):  
Terry D. Beacham ◽  
Clyde B. Murray
Keyword(s):  
Body Size ◽  
Genetic Analysis ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Male Body ◽  
Male Size ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Male Body Size ◽  
Size Classes ◽  
Heritability Estimates

Two small-sized and two large-sized male pink salmon (Oncorhynchus gorbuscha) were mated to each of four females, producing eight families sired by small males and eight sired by large males. The juveniles were reared for 500 d after fry emergence. Juvenile weight in the two male size classes was similar until the spring of the year of maturity, when juveniles sired by large males grew faster than those sired by small ones. Heritability estimates of weight based upon the dam component of variance increased during 500 d of rearing from 0.4 to 0.8. Heritability of weight based upon the sire component of variance generally ranged between 0.1 and 0.3. The large variation in male body size in spawning pink salmon populations may have resulted from different male breeding strategies.Key words: heritability, salmon, body size.

Genetic Aanalysis of Size in an Anadromous Population of Pink Salmon

1994 ◽  
Vol 51 (S1) ◽  
pp. 9-15 ◽  
Author(s):  
William W. Smoker ◽  
Anthony J. Gharrett ◽  
Michael S. Stekoll ◽  
John E. Joyce
Keyword(s):  
Variance Components ◽  
Genetic Basis ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Southeast Alaska ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Factors Affecting ◽  
Phenotypic Correlations ◽  
Sib Families ◽  
Mature Fish

Variation of size, particularly among males, has a significant genetic basis in pink salmon (Oncorhynchus gorbuscha) in Auke Creek, southeast Alaska. Heritability (h2), based on variance components of 118 full sib − 59 paternal half sib families of mature fish tagged as fry with coded micro wires, are higher in males (h2 length: 0.8 ± 0.3 (mean ± SE); h2 weight: 0.6 ± 0.2, based on sire effect) than in females (h2 length: 0.3 ± 0.2; h2 weight: 0.4 ± 0.2). Realized heritability probably would be smaller because of environment variability between brood years in factors affecting size and growth. Estimates based on regression of offspring means on fathers' values are smaller (h2 length: 0.4 ± 0.1 in males; 0.2 ± 0.1 in females; h2 weight: 0.0 in males and 0.1 ± 0.1 in females). Estimates of genetic, environmental, and phenotypic correlations of length and weight are all >0.7 (SEs <0.1). Estimates of genetic correlation between length and day of migration from the sea are near 0.4 ± 0.2; estimates of environmental and phenotypic correlations between these traits are smaller (<0.2, SEs <0.1).

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