Spawning Migration of Great Lakes Pink Salmon (Oncorhynchus Gorbuscha): Size and Sex Distributions, River Entrance and Exit

1986 ◽  
Vol 12 (2) ◽  
pp. 101-108 ◽  
Author(s):  
W. Kwain ◽  
George A. Rose
Keyword(s):  
Great Lakes ◽  
Pink Salmon ◽  
Spawning Migration ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha

Genetic Changes in Pink Salmon (Oncorhynchus gorbuscha) Following Their Introduction Into the Great Lakes

1987 ◽  
Vol 44 (4) ◽  
pp. 787-792 ◽  
Author(s):  
A. J. Gharrett ◽  
M. A. Thomason
Keyword(s):  
British Columbia ◽  
Great Lakes ◽  
Salt Water ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Major Step ◽  
River Population ◽  
Genetic Changes ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Allelic Frequencies

Pink salmon (Oncorhynchus gorbuscha) previously thought to require salt water for completion of their life cycle, have been firmly established in the Great Lakes following an accidental introduction into Lake Superior. We compare allelic frequencies at 27 protein-coding loci from collections of pink salmon from the Great Lakes with those from the anadromous population (Lakelse River, British Columbia) from which they were derived. Although the allelic frequencies in the Great Lakes collections are consistent with a single introduction, the frequencies observed in these collections differ substantially from those of the Lakelse River population. Alleles of G3p-1 and Ck-1, rarely observed (frequency < 0.005) in British Columbia population, are present in Great Lakes pink salmon at frequencies between 0.06 and 0.27. Smaller changes were observed at 11 other loci; 14 loci were monomorphic in all collections. Loss of variability in the Great Lakes was reflected by a decrease in average number of alleles per locus. Selection for physiologically tolerant phenotypes may have been necessary to establish this unique, self-perpetuating, freshwater population. The biochemical genetic changes we observed, however, can be adequately explained by genetic drift resulting from bottlenecks occurring at the first and at subsequent generations. Any decreases in survival resulting from freshwater intolerance would have exacerbated the bottlenecks. This adaptively distinct lineage produced by the ecological change coupled with the bottlenecks may be a major step toward speciation.

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.

Incidence and Effects of Sea Lamprey (Petromyzon marinus) Parasitism on Breeding Pink Salmon (Oncorhynchus gorbuscha) from the Carp River, Eastern Lake Superior

1987 ◽  
Vol 44 (9) ◽  
pp. 1562-1567 ◽  
Author(s):  
Douglas B. Noltie
Keyword(s):  
Population Dynamics ◽  
Great Lakes ◽  
Negative Impact ◽  
Lake Superior ◽  
Petromyzon Marinus ◽  
Pink Salmon ◽  
Reproductive Potential ◽  
Sea Lamprey ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha

The potentially important effect of Great Lakes pink salmon (Oncorhynchus gorbuscha) numbers on the population dynamics of parasitic sea lamprey (Petromyzon marinus) has thus far remained unassessed. This study reveals that despite their small size, pink salmon from the Carp River, eastern Lake Superior, sustain parasitism at rates and in body locations similar to other Great Lakes salmonids. In general, the incidence of sea lamprey parasitism increased with salmon length. Differences in marking rates between male and female salmon were attributable to their dimorphism in size: female pink salmon grew slower than males and bore more fresh wounds than males when sampled. Lamprey attacked fish of similar sizes in 1983 and 1984, but smaller ones in 1985. This parasitism had a negative impact on host breeding potential: marked fish were in poorer condition than unmarked ones. Marked males invested less biomass in gonad than did unmarked males, and wounded males occupied the spawning grounds for less time, thus reducing their reproductive potential. These results indicate that the population dynamics of both species may be determined in part by their mutual interaction.

Spawning Behavior and Early Life History of Pink Salmon (Oncorhynchus gorbuscha) in the Great Lakes

1982 ◽  
Vol 39 (10) ◽  
pp. 1353-1360 ◽  
Author(s):  
Wen-hwa Kwain
Keyword(s):  
Life History ◽  
Great Lakes ◽  
Early Life ◽  
Lake Superior ◽  
Pink Salmon ◽  
Early Life History ◽  
Oncorhynchus Gorbuscha ◽  
Spawning Behavior ◽  
Preferred Temperature ◽  
Pink Salmon Oncorhynchus Gorbuscha

Pink salmon (Oncorhynchus gorbuscha) from a single introduction to Lake Superior in 1956 have reproduced naturally and expanded into all the Great Lakes. Pink salmon feed at or near the surface as they approach spawning streams and some can still be found with food in the stomach on the spawning bed. Spawning behavior of these freshwater pink salmon is similar to that of marine stocks. Fecundity was 1060 ± 229 (24) per fish and total weight averaged 0.68 kg. Total mortality of embryos to 50% hatch ranged from 67 to 87% at five test temperatures (7, 9, 11, 13, 15 °C); 15 °C is considered to be the upper limit for freshwater pink salmon incubation. Juveniles moved downstream only at night and all juveniles usually took a month to complete this movement. Mean preferred temperature for pink salmon up to 36 wk old was 10 °C. Substantial numbers of pink salmon progeny of the 1975 year-class, which entered the Michipicoten River on Lake Superior to spawn in 1977 survived to, and matured at, each age from II to IV yr in a freshwater laboratory environment.Key words: pink salmon, feeding, spawning behavior, fecundity, incubation, emigration, preferred temperature, early life history, age IV, late maturation

First Evidence for Even-Year Spawning Pink Salmon, Oncorhynchus gorbuscha, in Lake Superior

1978 ◽  
Vol 35 (10) ◽  
pp. 1373-1376 ◽  
Author(s):  
Wen-hwa Kwain ◽  
J. A. Chappel
Keyword(s):  
Great Lakes ◽  
Key Words ◽  
Lake Superior ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha

Nine even-year spawning pink salmon, Oncorhynchus gorbuscha, were taken in Steel River, Lake Superior, Ontario, in 1976. The possible origin of these fish was from unknown plantings or spawning of 3-yr-old, odd-year spawning pink salmon. Key words: Great Lakes, distribution, salmon maturation, spawning age, introduced salmon

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