Climate effects on size‐at‐age and growth rate of Chinook Salmon ( Oncorhynchus tshawytscha ) in the Fraser River, Canada

2020 ◽  
Vol 29 (5) ◽  
pp. 381-395
Author(s):  
Yi Xu ◽  
A. Scott Decker ◽  
Charles K. Parken ◽  
Lynda M. Ritchie ◽  
David A. Patterson ◽  
...  
PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1392
Author(s):  
Juan C. Levesque

Ladyfish (Elopssp) are a common and economically valuable coastal nearshore species found along coastal beaches, bays, and estuaries of the southeastern United States, and subtropical and tropical regions worldwide. Previously, ladyfish were a substantial bycatch in Florida’s commercial fisheries, but changes in regulations significantly reduced commercial landings. Today, ladyfish are still taken in commercial fisheries in Florida, but many are also taken by recreational anglers. Life-history information and research interest in ladyfish is almost non-existent, especially information on age and growth. Thus, the overarching purpose of this study was to expand our understanding of ladyfish age and growth characteristics. The specific objectives were to describe, for the first time, age, growth, and recruitment patterns of juvenile ladyfish from the east coast of Florida (USA). In the Indian River Lagoon (IRL), annual monthly length-frequency distributions were confounded because a few small individuals recruited throughout the year; monthly length-frequency data generally demonstrated a cyclical pattern. The smallest were collected in September and the largest in May. Post-hoc analysis showed no significant difference in length between August and May, or among the other months. In Volusia County (VC), annual monthly length-frequency distribution demonstrated growth generally occurred from late-winter and spring to summer. The smallest ladyfish were collected in February and the largest in August. On average, the absolute growth rate in the IRL was 36.3 mm in 60 days or 0.605 mm day−1. Cohort-specific daily growth rates, elevations, and coincidentals were similar among sampling years. Cohort-specific growth rates ranged from 1.807 in 1993 to 1.811 mm day−1in 1994. Overall, growth was best (i.e., goodness of fit) described by exponential regression. On average, the absolute growth rate in VC was 28 mm in 150 days or 0.1866 mm day−1. Cohort-specific daily growth rates were significantly different among sampling years; however, the elevations and coincidentals were similar. Cohort-specific growth rates ranged from 1.741 in 1994 to 1.933 mm day−1in 1993. Mean ladyfish growth was best described by linear regression; however, natural growth was explained better by exponential regression. In the IRL, the corrected exponential growth equation yielded a size-at-age 1 of 156.0 mm SL, which corresponded to an estimated growth rate of 0.4356 mm day−1. In VC, the corrected exponential growth equation yielded a size-at-age 1 of 80 mm SL corresponding to an estimated growth rate of 0.2361 mm day−1.


1993 ◽  
Vol 50 (2) ◽  
pp. 435-442 ◽  
Author(s):  
Daniel D. Heath ◽  
Nicholas J. Bernier ◽  
John W. Heath ◽  
George K. Iwama

Eight full- and half-sib families of chinook salmon (Oncorhynchus tshawytscha) were held during egg development at two temperatures (8.0 and 10.2 °C). As fry, these families were measured for relative growth rate, initial and final wet weight, hematocrit values before and 2 h after a 30-s handling stress, and plasma cortisol and glucose concentrations before and after stress. Significant sire effects were found for all measured traits, and significant dam effects were found for all traits except for the poststress increases in cortisol concentrations. There were significant genotype-by-environment interactions for all traits except unstressed (control) plasma glucose concentrations. Incubation temperature had a significant effect on relative growth rate and final wet weight only. We found a significant correlation between poststress plasma glucose concentration and relative growth rate for all fish, independent of family, while resting plasma cortisol concentration and poststress hematocrit correlated with wet weight only when analyzed within the eight individual families. Genetic contributions to stress-related parameters and genotype-by-environment interactions should be considered as a factor in stress-related research with fish.


1981 ◽  
Vol 38 (12) ◽  
pp. 1636-1656 ◽  
Author(s):  
W. E. Ricker

Of the five species of Pacific salmon in British Columbia, chinook salmon (Oncorhynchus tshawytscha) and coho salmon (O. kisutch) are harvested during their growing seasons, while pink salmon (O. gorbuscha), chum salmon (O. keta), and sockeye salmon (O. nerka) are taken only after practically all of their growth is completed. The size of the fish caught, of all species, has decreased, but to different degrees and over different time periods, and for the most part this results from a size decrease in the population. These decreases do not exhibit significant correlations with available ocean temperature or salinity series, except that for sockeye lower temperature is associated with larger size. Chinook salmon have decreased greatly in both size and age since the 1920s, most importantly because nonmaturing individuals are taken by the troll fishery; hence individuals that mature at older ages are harvested more intensively, which decreases the percentage of older ones available both directly and cumulatively because the spawners include an excess of younger fish. Other species have decreased in size principally since 1950, when the change to payment by the pound rather than by the piece made it profitable for the gill-netters to harvest more of the larger fish. Cohos and pinks exhibit the greatest decreases, these being almost entirely a cumulative genetic effect caused by commercial trolls and gill nets removing fish of larger than average size. However, cohos reared in the Strait of Georgia have not decreased in size, possibly because sport trolling has different selection characteristics or because of the increase in the hatchery-reared component of the catch. The mean size of chum and sockeye salmon caught has changed much less than that of the other species. Chums have the additional peculiarity that gill nets tend to take smaller individuals than seines do and that their mean age has increased, at least between 1957 and 1972. That overall mean size has nevertheless decreased somewhat may be related to the fact that younger-maturing individuals grow much faster than older-maturing ones; hence excess removal of the smaller younger fish tends to depress growth rate. Among sockeye the decrease in size has apparently been retarded by an increase in growth rate related to the gradual cooling of the ocean since 1940. However, selection has had two important effects: an increase in the percentage of age-3 "jacks" in some stocks, these being little harvested, and an increase in the difference in size between sockeye having three and four ocean growing seasons, respectively.Key words: Pacific salmon, age changes, size changes, fishery, environment, selection, heritability


1997 ◽  
Vol 54 (7) ◽  
pp. 1585-1592 ◽  
Author(s):  
M J Bradford ◽  
G C Taylor

Immediately after emergence from spawning gravels, fry of stream-type chinook salmon (Oncorhynchus tshawytscha) populations from tributaries of the upper Fraser River, British Columbia, distribute themselves downstream from the spawning areas, throughout the natal stream, and into the Fraser River. We tested the hypothesis that this range in dispersal distances is caused by innate differences in nocturnal migratory tendency among individuals. Using an experimental stream channel, we found repeatable differences in downstream movement behaviour among newly emerged chinook fry. Fish that moved downstream were larger than those that held position in the channel. However, the incidence of downstream movement behaviours decreased over the first 2 weeks after emergence. We propose that the variation among individuals in downstream movement behaviour we observed leads to the dispersal of newly emerged fry throughout all available rearing habitats. Thus, between- and within-population variation in the freshwater life history observed in these populations may be caused by small differences in the behaviour of individuals.


1997 ◽  
Vol 54 (1) ◽  
pp. 137-146
Author(s):  
E G Dawe ◽  
P C Beck

We describe size at age, growth, and population structure of short-finned squid (Illex illecebrosus) from Newfoundland waters during 1990. Ages were estimated from statolith increment counts and used to back-calculate hatching dates. Hatching ranged between December and June with the hatching months of March to May predominating. Constant interchange of individuals in the inshore population was evident in that the modal month of hatching progressed from March within the earliest (July) sample to May within the latest (November) sample. Within the mantle length range available, growth was adequately expressed by a linear model. Females grew faster than males, and during the March to May months of hatching, length at age and growth rate increased with hatching month. This positive effect of late time of hatching was also seen in growth in mass and in gonad development and sexual maturation.


2019 ◽  
Vol 76 (6) ◽  
pp. 856-870 ◽  
Author(s):  
Skip McKinnell

Pulses of abundance in salmon migrations can arise from single populations arriving at different times, from multiple populations with different timing characteristics, or as a combination of these. Daily observations typically record an aggregate measure of abundance passing some location rather than the abundances of the individual components. An objective method is described that partitions a compound migration into its component parts by exploiting differences in the characteristics of each pulse. Simulated data were used to demonstrate when greater model complexity may be desirable. Three case studies of increasing complexity (Chilko Lake sockeye salmon smolts (Oncorhynchus nerka), large adult Columbia River Chinook salmon (Oncorhynchus tshawytscha), Fraser River salmon test fishery) demonstrate how the model can be applied in practice. Results indicated that Chilko Lake smolts rarely emigrate to sea as a single pulse, that the dates used to distinguish the spring run of Chinook salmon in the Columbia River may be overestimating its abundance, and that pulses of sockeye salmon abundance in a Fraser River ocean test fishery in 2014 may have arisen from some factor other than population composition.


2015 ◽  
Author(s):  
Juan C Levesque

Ladyfish (Elops sp) are a common and economically valuable coastal nearshore species found along coastal beaches, bays, and estuaries of the southeastern United States, and subtropical and tropical regions worldwide. Previously, ladyfish were a substantial bycatch in Florida’s commercial fisheries, but changes in regulations significantly reduced commercial landings. Today, ladyfish are still taken in commercial fisheries in Florida, but many are also taken by recreational anglers. Life-history information and research interest in ladyfish is almost non-existent, especially information on age and growth. Thus, the overarching purpose of this study was to expand our understanding of ladyfish age and growth characteristics. The specific objectives were to describe, for the first time, age, growth, and recruitment patterns of juvenile ladyfish from the east coast of Florida (USA). In the Indian River Lagoon (IRL), annual monthly length-frequency distributions were confounded because a few small individuals recruited throughout the year; monthly length-frequency data generally demonstrated a cyclical pattern. The smallest were collected in September and the largest in May. Post-hoc analysis showed no significant difference in length between August and May, or among the other months. In Volusia County (VC), annual monthly length-frequency distribution demonstrated growth generally occurred from late-winter and spring to summer. The smallest ladyfish were collected in February and the largest in August. On average, the absolute growth rate in the IRL was 36.3 mm in 60 days or 0.605 mm day-1. Cohort-specific daily growth rates, elevations, and coincidentals were similar among sampling years. Cohort-specific growth rates ranged from 1.807 in 1993 to 1.811 mm day-1 in 1994. Overall, growth was best (i.e., goodness of fit) described by exponential regression. On average, the absolute growth rate in VC was 28 mm in 150 days or 0.1866 mm day-1. Cohort-specific daily growth rates were significantly different among sampling years; however, the elevations and coincidentals were similar. Cohort-specific growth rates ranged from 1.741 in 1994 to 1.933 mm day-1 in 1993. Mean ladyfish growth was best described by linear regression; however, natural growth was explained better by exponential regression. In the IRL, the corrected exponential growth equation yielded a size-at-age 1 of 156.0 mm SL, which corresponded to an estimated growth rate of 0.4356 mm day-1. In VC, the corrected exponential growth equation yielded a size-at-age 1 of 80 mm SL corresponding to an estimated growth rate of 0.2361 mm day-1.


2015 ◽  
Author(s):  
Juan C Levesque

Ladyfish (Elops sp) are a common and economically valuable coastal nearshore species found along coastal beaches, bays, and estuaries of the southeastern United States, and subtropical and tropical regions worldwide. Previously, ladyfish were a substantial bycatch in Florida’s commercial fisheries, but changes in regulations significantly reduced commercial landings. Today, ladyfish are still taken in commercial fisheries in Florida, but many are also taken by recreational anglers. Life-history information and research interest in ladyfish is almost non-existent, especially information on age and growth. Thus, the overarching purpose of this study was to expand our understanding of ladyfish age and growth characteristics. The specific objectives were to describe, for the first time, age, growth, and recruitment patterns of juvenile ladyfish from the east coast of Florida (USA). In the Indian River Lagoon (IRL), annual monthly length-frequency distributions were confounded because a few small individuals recruited throughout the year; monthly length-frequency data generally demonstrated a cyclical pattern. The smallest were collected in September and the largest in May. Post-hoc analysis showed no significant difference in length between August and May, or among the other months. In Volusia County (VC), annual monthly length-frequency distribution demonstrated growth generally occurred from late-winter and spring to summer. The smallest ladyfish were collected in February and the largest in August. On average, the absolute growth rate in the IRL was 36.3 mm in 60 days or 0.605 mm day-1. Cohort-specific daily growth rates, elevations, and coincidentals were similar among sampling years. Cohort-specific growth rates ranged from 1.807 in 1993 to 1.811 mm day-1 in 1994. Overall, growth was best (i.e., goodness of fit) described by exponential regression. On average, the absolute growth rate in VC was 28 mm in 150 days or 0.1866 mm day-1. Cohort-specific daily growth rates were significantly different among sampling years; however, the elevations and coincidentals were similar. Cohort-specific growth rates ranged from 1.741 in 1994 to 1.933 mm day-1 in 1993. Mean ladyfish growth was best described by linear regression; however, natural growth was explained better by exponential regression. In the IRL, the corrected exponential growth equation yielded a size-at-age 1 of 156.0 mm SL, which corresponded to an estimated growth rate of 0.4356 mm day-1. In VC, the corrected exponential growth equation yielded a size-at-age 1 of 80 mm SL corresponding to an estimated growth rate of 0.2361 mm day-1.


2019 ◽  
Vol 11 (4) ◽  
pp. 325-334
Author(s):  
Katarina H. Doughty ◽  
Shawn R. Garner ◽  
Mark A. Bernards ◽  
John W. Heath ◽  
Bryan D. Neff

Abstract There is considerable interest in developing diets that maintain growth performance and market appeal for salmon aquaculture while relying less on fishmeal as a major ingredient. Here, we compared growth rate, survival, fat content, tissue colouration and carotenoid levels (astaxanthin) in Chinook salmon (Oncorhynchus tshawytscha) fed two diets. The first diet was a typical commercial salmon diet with 59% fishmeal content, while the second diet reduced the fishmeal content to 15% (75% reduction) and substituted 28% corn gluten meal and 16% poultry meal. Over an approximately 14-month growth period, we found no significant difference between fish fed the high fishmeal or low fishmeal diet in either growth rate or survival. Individuals fed the low fishmeal diet did have 25% higher total body fat percentage than those fed the high fishmeal diet. Individuals fed the low fishmeal diet also had flesh that was significantly less red than fish fed the high fishmeal diet. Carotenoid analysis confirmed that the change in tissue colour was the result of reduced astaxanthin levels in salmon fed the low fishmeal diet. Due to the importance of red tissue colour for the market appeal of salmon, the corn gluten and poultry meal diet is not viable for salmon aquaculture in its present formulation, but our results suggest further modifications to the diet that could mitigate this effect.


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