Differences in breeding Lake Superior pink salmon (Oncorhynchus gorbuscha (Walbaum)) associated with variation in thyroid hyperplasia

1988 ◽  
Vol 66 (12) ◽  
pp. 2688-2694 ◽  
Author(s):  
Douglas B. Noltie
Keyword(s):  
Lake Superior ◽  
Pink Salmon ◽  
Lesion Size ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Wide Range ◽  
Post Spawning ◽  
Delayed Maturation ◽  
Thyroid Hyperplasia ◽  
Lesion Severity

Pink salmon (Oncorhynchus gorbuscha (Walbaum)) from eastern Lake Superior exhibit various degrees of thyroid hyperplasia. A link between goitrogenesis and growth is suggested by the increased prevalence of large lesions among large fish of both sexes. Despite males being larger than females, however, lesion prevalence did not differ between the sexes. More large lesions occurred among late migrants, especially males, indicating a seasonal increase in hyperplasticity. Delayed stream entry occurred in overtly lesioned fish of both sexes, evidence of a possible inhibition of maturation. Males and females differed in condition (weight-at-length) with lesion severity. Females with overt lesions showed reduced secondary sexual character development, more so than males. The pre- and post-spawning testis characteristics of males generally did not differ with lesion size, although the testes of spawned-out males with large lesions did have higher water contents. In females, the reduced water content of eggs in severely lesioned individuals was evidence of delayed maturation. Enlarged livers occurred in badly lesioned females, but not in males. In neither sex did severely lesioned fish exhibit shorter breeding life-spans. In overview, this study demonstrates that a wide range of effects is associated with differences in the severity of thyroid hyperplasia exhibited by Lake Superior pink salmon, these also being mediated by apparent differences in physiology between the sexes.

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.

Migratory dynamics and characteristics of breeding pink salmon (Oncorhynchus gorbuscha) from the Carp River, eastern Lake Superior

1990 ◽  
Vol 68 (4) ◽  
pp. 684-693 ◽  
Author(s):  
Douglas B. Noltie
Keyword(s):  
Lake Superior ◽  
Pink Salmon ◽  
Life Cycles ◽  
Oncorhynchus Gorbuscha ◽  
Gonad Maturation ◽  
Breeding Ecology ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Light Levels ◽  
Breeding Migration ◽  
Fish Remains

The pink salmon (Oncorhynchus gorbuscha) inhabiting the Great Lakes are unique to their species, the completion of their life cycles occurring entirely in fresh water. This report describes the breeding migration and characteristics of spawners from the Carp River, an eastern Lake Superior tributary 70 km north of Sault Ste. Marie, Ontario. Movement into the stream began at dusk each evening in 1983, seemingly in response to decreasing light levels. Nightly catch numbers varied through the 1983, 1984, and 1985 runs with date, river discharge, wind-generated turbulence, and water temperatures, although the influence of these factors differed with sex and season. Spawners varied in size through the runs each year but not in the same fashion. Spawner size and condition varied yearly in apparent response to prey abundance. Gonad maturation was complete on stream entry more often in males than in females, though this difference was less pronounced further upstream or after time spent in the river. Degree of secondary sexual character development, complete on stream entry in both sexes, differed in even- and odd-year spawners in relation to condition. The recovery rates of spawned-out males and females did not differ. Tagged fish wandered from the Carp River at a rate of at least 7%, many to spawn in adjacent streams. Despite between-year differences in some parameters, much of the breeding ecology of these fish remains comparable to that of anadromous pink salmon.

External Morphology of the Pink Salmon, Oncorhynchus gorbuscha, Introduced into Lake Superior

1979 ◽  
Vol 36 (10) ◽  
pp. 1283-1287 ◽  
Author(s):  
Richard E. Berg
Keyword(s):  
Key Words ◽  
Lake Superior ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Morphometric Measurements ◽  
Male Fish ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
The Pacific ◽  
Male Head ◽  
Degree Of Differentiation

Meristic and morphometric measurements were taken from 33 male and 44 female mature pink salmon, Oncorhynchus gorbuscha, collected in three Lake Superior tributaries in Marquette County, Michigan. Significant sexual differences were found for eight characteristics in males and two in females. The male fish had a greater degree of differentiation in the head and hump regions; females had larger and longer anal fins. The Lake Superior fish were found to have shorter bodies, larger and longer fins, and more exaggerated development in the male head and hump than has been reported for the Pacific populations. Key words: pink salmon, salmonids, exotic species, Lake Superior, morphology

Occurrence of Pink Salmon (Oncorhynchus gorbuscha) in Lake Huron

1975 ◽  
Vol 32 (3) ◽  
pp. 402-404 ◽  
Author(s):  
John J. Collins
Keyword(s):  
Lake Superior ◽  
Pink Salmon ◽  
Lake Huron ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha

Pink salmon (Oncorhynchus gorbuscha), which were introduced into Lake Superior in 1956 and have produced eight natural generations there, have now appeared in Lake Huron. The first pink salmon was taken in Ontario waters of Lake Huron in 1971. Successful spawning was observed in one tributary in 1973, indicating that pink salmon could become established in Lake Huron.

Intrapopulation Variation in the Breeding of Male Pink Salmon (Oncorhynchus gorbuscha) from a Lake Superior Tributary

1990 ◽  
Vol 47 (1) ◽  
pp. 174-179 ◽  
Author(s):  
Douglas B. Noltie
Keyword(s):  
Lake Superior ◽  
Pink Salmon ◽  
Life History Strategies ◽  
Oncorhynchus Gorbuscha ◽  
Breeding Ground ◽  
Spawning Ground ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Intrapopulation Variation ◽  
Morphological Studies ◽  
Proximate Factors

Studies of breeding pink salmon (Oncorhynchus gorbuscha) from the Carp River, eastern Lake Superior, indicate that males seek fertilizations using two behavioural tactics. In 1985, a large run resulted in high breeding ground densities. During this run, males that resembled females were seen seeking fertilizations by sneaking rather than by competing for proximity to females. Morphological studies in 1985 confirmed the presence of males resembling females, their secondary sexual characters (hump height) being relatively less developed than in typical males. Although in poorer condition, such female-like males were reproductively mature, had returned to spawn at ages typical for this population, and had committed biomass to gonad no differently than had typical males. Furthermore, their spawning performance did not differ from typical males, as assessed both by the amount of gonad they retained unspawned at death and by their spawning ground life expectancies. In contrast, males attempting to sneak fertilizations were not observed during the small 1984 run when densities were low and males were generally in better condition than in 1985. Together, these results indicate that male pink salmon exhibit alternative breeding tactics. However, the demonstration of these tactics appears linked more to proximate factors (density and condition) than to divergent life history strategies as in other salmonid species.

Decision Analysis of a Large-Scale Fishing Experiment Designed to Test for a Genetic Effect of Size-Selective Fishing on British Columbia Pink Salmon (Oncorhynchus gorbuscha)

1992 ◽  
Vol 49 (7) ◽  
pp. 1305-1314 ◽  
Author(s):  
Murdoch K. McAllister ◽  
Randall M. Peterman
Keyword(s):  
British Columbia ◽  
Decision Analysis ◽  
Large Scale ◽  
Economic Value ◽  
Pink Salmon ◽  
Genetic Effect ◽  
Status Quo ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Wide Range

Past work suggested that size-selective harvesting of large fish combined with heritability of body size has caused the large (up to 34%) decrease in mean adult weight of British Columbia pink salmon (Oncorhynchus gorbuscha) since 1950. In a companion paper (Can. J. Fish. Aquat. Sei. 49: 1294–1304) we evaluated the statistical performance of a large-scale fishing experiment that could enable managers to test this hypothesis and at the same time increase catch biomass if that hypothesis were correct. In this paper we evaluate the economic performance of the proposed experiment using Monte Carlo simulation and decision analysis under a wide range of conditions that encompasses existing biological uncertainties. We accounted for uncertainties through prior probabilities placed on two key biological hypotheses. We computed the expected economic value of catch biomass for the experimental and current nonexperimental (status quo) management strategies using a 20-yr time horizon and a 10-yr experiment with four spatial replicates. Under a variety of discount rates, the expected economic value of experimentation exceeded that of status quo management in most of the conditions examined, in some cases by as much as 60%.

Survival of Puget Sound chinook salmon (Oncorhynchus tshawytscha) in response to climate-induced competition with pink salmon (Oncorhynchus gorbuscha)

2004 ◽  
Vol 61 (9) ◽  
pp. 1756-1770 ◽  
Author(s):  
Gregory T Ruggerone ◽  
Frederick A Goetz
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Pink Salmon ◽  
Puget Sound ◽  
Oncorhynchus Gorbuscha ◽  
First Year ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Growth And Survival ◽  
Coastal Streams ◽  
Delayed Maturation

We tested for competition between pink salmon (Oncorhynchus gorbuscha) and chinook salmon (Oncorhynchus tshawytscha) originating from rivers in the Puget Sound area using coded-wire-tagged subyearling hatchery chinook salmon. Following a 2-year life cycle, many juvenile pink salmon enter Puget Sound in even-numbered years, whereas few migrate during odd-numbered years. During 1984–1997, juvenile chinook salmon released during even-numbered years experienced 59% lower survival than those released during odd-numbered years, a trend consistent among 13 chinook salmon stocks. Lower even-numbered-year survival of chinook salmon was associated with reduced first-year growth and survival and delayed maturation. In contrast, chinook salmon released into coastal streams, where few pink salmon occur, did not exhibit an alternating-year pattern of survival, suggesting that the interaction occurred within Puget Sound and the lower Strait of Georgia. Unexpectedly, the survival pattern of Puget Sound chinook salmon was reversed prior to the 1982–1983 El Niño: chinook salmon survival was higher when they migrated with juvenile pink salmon during 1972–1983. We hypothesize that chinook salmon survival changed as a result of a shift from predation- to competition-based mortality in response to recent declines in predator and prey abundances and increases in pink salmon abundance. Alternating-year mortality accounted for most of the 50% decline in marine survival of chinook salmon between 1972–1983 and 1984–1997.

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

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