Brook Trout (Salvelinus fontinalis) Population Structure in Acidified Lac Tantaré, Quebec

1984 ◽  
Vol 41 (6) ◽  
pp. 865-877 ◽  
Author(s):  
Jean-Jacques Frenette ◽  
Julian J. Dodson
Keyword(s):  
Population Structure ◽  
Brook Trout ◽  
Sexual Maturity ◽  
Reproductive Effort ◽  
Salvelinus Fontinalis ◽  
Individual Growth ◽  
Toxic Stress ◽  
Age Classes ◽  
Recruitment Failure ◽  
Trout Population

To present evidence of acid-induced stress, we studied the population structure and distribution of brook trout (Salvelinus fontinalis) in acidified Lac Tantaré, Quebec. Trout greater than 21 cm (FL) represented only 16.2 and 10% of the population sampled in 1979 and 1980, respectively. Survival rates of trout from 1979 to 1980 indicated higher survival among individuals > 25 cm, mortality occurring primarily among fish of 13–25 cm. The marked decline in numbers of fish occurring at 21 cm coincided with the size at which 50% of the female trout population reached sexual maturity, suggesting that postspawning mortality contributes to the high mortality observed among these fish. Comparisons of population and individual growth rates revealed that smaller fish of age-classes 1 to 5 suffer higher mortality than do the larger individuals of these age-classes, implicating mortality agents other than those related to spawning. We provide evidence to support the hypothesis that the most probable cause of mortality is size-related differential exposure to toxic stress whereby small brook trout (< 25 cm) are found in lake areas (brooks) exhibiting the most potentially toxic combination of pH and aluminum, thus enhancing the exposure of the most susceptible part of the population to toxic stress. Large brook trout [Formula: see text] are found in the "safest" lake areas (springs), thus diminishing the exposure of the least susceptible part of the population to toxic stress and enhancing survival. Female trout exhibit delayed sexual maturity relative to other Quebec populations, attaining 50% maturity at age 3 and a length of 21–24 cm such that the major part of the population's reproductive effort is provided by those fish representing only 15% of the population in 1979 and 1980. During the October spawning season, 20% of potential spawners exhibited retarded oogenesis. These reductions in reproductive effort and changes in spawning site selection provide evidence in support of the hypothesis that recruitment failure may be occurring in the Tantaré brook trout population.

Genetic Variation and Fitness: A Test in a Naturalized Population of Brook Trout (Salvelinus fontinalis)

1991 ◽  
Vol 48 (11) ◽  
pp. 2152-2162 ◽  
Author(s):  
Arunas P. Liskauskas ◽  
Moira M. Ferguson
Keyword(s):  
Brook Trout ◽  
Sexual Maturity ◽  
Salvelinus Fontinalis ◽  
Positive Association ◽  
Somatic Tissue ◽  
Age Classes ◽  
Life History Stages ◽  
Young Of The Year ◽  
The Relationship ◽  
Provincial Park

The relationship between enzyme heterozygosity and several components of fitness (size and survival) was examined in a naturalized population of brook trout (Salvelinus fontinalis) from Algonquin Provincial Park, Ontario. Significant differences in allele frequency and the number of heterozygous loci per individual were found among five age classes spanning most of the life history stages of brook trout in this population. A young of the year (YOY) cohort sampled after a period of high natural mortality had significantly greater numbers of heterozygous loci per individual than YOY sampled shortly after emergence from redd sites. A positive association between heterozygosity and size was only found in YOY sampled in June and not in the other age classes in which sexual maturity was not a complicating factor. The association between heterozygosity and size was affected by the onset of sexual maturity. Significant negative regressions between multilocus or single locus heterozygosity and size were found in mature males whereas heterozygosity was positively associated with size in females. These dissimilarities may be the result of differences in growth rates prior to sexual maturation and differential allocation of energy towards gametic and somatic tissue.

Experimental Plantings of Brook Trout (Salvelinus fontinalis) from Furunculosis-Infected Stock

1968 ◽  
Vol 25 (12) ◽  
pp. 2643-2649 ◽  
Author(s):  
L. A. McDermott ◽  
A. H. Berst
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Infected Fish ◽  
Aeromonas Salmonicida ◽  
Control Fish ◽  
Southern Ontario ◽  
Trout Population ◽  
Hatchery Stock ◽  
Associated Species ◽  
Made In

Preliminary sampling revealed the presence of furunculosis disease in the resident brook trout population of the southern Ontario trout stream used in this study.Two plantings of marked yearling brook trout were made in the study area in 1966; one in the spring, and the other in the fall. The spring planting consisted of 1000 brook trout with a predetermined incidence of furunculosis infection and an equal number of trout with no evidence of infection. The fall planting consisted of 2000 brook trout with a known incidence of furunculosis infection.The stream was electrofished periodically during the 2-year period after the first planting. A total of 445 brook trout (140 of the planted hatchery stock, and 305 resident trout) and 127 fish of associated species were captured and examined for the presence of Aeromonas salmonicida, causative agent of furunculosis.Recovery rates of the "infected" and "noninfected" stocks of brook trout were similar, and there was no evidence of transmission of A. salmonicida from the infected fish to the control fish, nor the resident population of brook trout and other species of fish captured.

scholarly journals Brook trout (Salvelinus fontinalis) extinction in small boreal lakes revealed by ephippia pigmentation: a preliminary analysis

2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Alexandre Bérubé Tellier ◽  
Paul E. Drevnick ◽  
Andrea Bertolo
Keyword(s):  
Brook Trout ◽  
Fish Assemblages ◽  
Salvelinus Fontinalis ◽  
Sediment Cores ◽  
Experimental Studies ◽  
Cost Effective ◽  
Fish Predation ◽  
Boreal Lakes ◽  
Predation Pressure ◽  
Trout Population

<p>Ephippium pigmentation is a plastic trait which can be related to a trade-off between visual predation pressure and better protection of cladoceran eggs against different types of stress. Experimental studies showed that planktivorous fish exert a greater predation pressure on individuals carrying darker ephippia, but little is known about the variation of ephippium pigmentation along gradients of fish predation pressure in natural conditions. For this study, our experimental design included four small boreal lakes with known fish assemblages. Two of the lakes have viable brook trout (<em>Salvelinus fontinalis</em>) populations, whereas the other two lakes experienced brook trout extinctions during the 20<sup>th</sup> century. Cladoceran ephippia were extracted from sediment cores at layers corresponding to the documented post- extinction phase (1990's) and from an older layer (1950's) for which the brook trout population status is not known precisely. Our first objective was to determine whether brook trout extinction has a direct effect on both ephippium pigmentation and size. Our second objective was to give a preliminary assessment of the status of brook trout populations in the 1950's by comparing the variation in ephippia traits measured from this layer to those measured in the 1990's, for which the extinction patterns are well known. Cost-effective image analysis was used to assess variation in pigmentation levels in ephippia. This approach provided a proxy for the amount of melanin invested in each ephippium analysed. Our study clearly shows that ephippium pigmentation may represent a better indicator of the presence of fish predators than ephippium size, a trait that showed a less clear pattern of variation between lakes with and without fish. For the 1990's period, ephippia from fishless lakes were darker and showed a slight tendency to be larger than ephippia from lakes with brook trout. However, no clear differences in either ephippium size or pigmentation were observed between the 1990's and 1950's layers within each lake. This suggests that brook trout extinction already occurred before the 1950’s, or that brook trout population abundance was already extremely low before and after the 1990’s. Our preliminary study shows that ephippium pigmentation can be used as a tool to quickly assess present and past predation levels on zooplankton when only sediment samples are available.</p>

Trout Production and Eels in Bill Lake, Saguenay County, Quebec

1973 ◽  
Vol 30 (9) ◽  
pp. 1398-1401 ◽  
Author(s):  
J. F. O’Connor ◽  
G. Power
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Annual Production ◽  
Anguilla Rostrata ◽  
Apparent Position ◽  
Trout Population ◽  
American Eels

Competition and predation by American eels (Anguilla rostrata) is believed to have substantially reduced trout population and production in Bill Lake. Brook trout (Salvelinus fontinalis) occurred at densities of 7/ha; biomass of 0.34 kg/ha and annual production was estimated at 0.21 kg/ha. This is considerably less than values for trout density, biomass, and production in other lakes in the Matamek watershed from which eels appear to be absent. Eels in Bill Lake are old and large but not numerous, in keeping with their apparent position as top carnivores.

Resource partitioning between brook trout (Salvelinus fontinalis Mitchill) and creek chub (Semotilus atromaculatus Mitchill) in selected oligotrophic lakes of southern Quebec

1982 ◽  
Vol 60 (7) ◽  
pp. 1612-1617 ◽  
Author(s):  
Pierre Magnan ◽  
Gérard J. FitzGerald
Keyword(s):  
Spatial Distribution ◽  
Resource Partitioning ◽  
Brook Trout ◽  
Food Habits ◽  
Salvelinus Fontinalis ◽  
Niche Shift ◽  
Sympatric Populations ◽  
Semotilus Atromaculatus ◽  
Trout Population ◽  
Creek Chub

The spatial distribution, food habits, and growth of an allopatric brook trout (Salvelinus fontinalis) population was compared with a trout population coexisting with creek chub (Semotilus atromaculatus). Sympatric trout differed in spatial distribution and food habits from allopatric trout suggesting a niche shift of the trout when they live with creek chub. Also, although there is a certain overlap in diet and spatial distribution, sympatric populations of the two species differed on these resource axes. However, growth of sympatric trout is not clearly related to the presence or absence of the creek chub, suggesting that factors other than interspecific competiton may affect growth in the seven study lakes.

Exploitation of Self-Sustaining Ontario Stream Populations of Brown Trout (Salmo trutta) and Brook Trout (Salvelinus fontinalis)

1970 ◽  
Vol 27 (6) ◽  
pp. 1087-1102 ◽  
Author(s):  
T. Lawrence Marshall ◽  
Hugh R. MacCrimmon
Keyword(s):  
Population Structure ◽  
Brown Trout ◽  
Brook Trout ◽  
Standing Crop ◽  
Salmo Trutta ◽  
Salvelinus Fontinalis ◽  
Catch Per Unit Effort ◽  
High Quality ◽  
Exploitation Rate ◽  
Brown Trout Salmo Trutta

The August standing crop of harvestable brown trout (Salmo trutta, 90%), and brook trout (Salvelinus fontinalis, 9%) in the upper Sydenham River, Ont., was estimated at 499 trout/ha (63.2 kg/ha) during 1966 and 1967. Brown trout were of age I (68%), age II (23%), and the remainder of ages III, IV, V, and XIII. Brook trout were ages I (95%) and II only.The average annual harvest by 1501 anglers was 1135 fish (64% brown, 35% brook trout) at a rate of 0.34 fish/hr. Exploitation of the preseason standing populations of brown and brook trout was 23 and 59%, respectively. Catch per unit effort from the downriver section (all brown trout of ages II–IV and mean length of 34.0 cm) averaged 0.10 at an angling pressure of 264 hr/ha. An upriver section occupied predominantly (90%) by brown trout of age I–III and mean length of 26.8 cm yielded 0.67 trout/hr at an angling pressure of 251 hr/ha.The population structure, growth, and exploitation rate of naturalized brown trout favours its use in providing continuous angling of creditable quality in heavily fished headwater streams. Coexistence of self-sustaining populations of brown and brook trout provide a sustained, high-quality mixed fishery.

Impact of Brook Trout (Salvelinus fontinalis) Predation on the Crayfish Orconectes virilis in Three Michigan Lakes

1979 ◽  
Vol 36 (10) ◽  
pp. 1191-1196 ◽  
Author(s):  
H. Gowing ◽  
W. T. Momot
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
First Year ◽  
Orconectes Virilis ◽  
Trout Population ◽  
Production Growth ◽  
First Year Of Life ◽  
The Cost ◽  
Slow Growing ◽  
Northern Michigan

The crayfish Orconectes virilis is a major component of the benthos of three small lakes in northern Michigan. These lakes contained stocked brook trout (Salvelinus fontinalis) populations (age-0 and age-I) at densities of 188, 411, and 1398 fish/ha. Crayfish were preyed upon by brook trout, but only during their first year of life. Two-year production of age-0 crayfish was approximately 94 kg in each lake; brook trout consumed only about 1–2% in lakes with lower density offish. Even with greater trout density and accompanying higher rate of exploitation (40%), there was no impact on recruitment of young crayfish because compensatory mortality of crayfish occurred in lakes with less trout predation. However, stocking trout at higher densities decreased trout growth and condition. While 2-yr production was highest (59 kg/ha) in the lake stocked at the highest density and lowest (17 kg/ha) in one stocked at the lowest density, the former was achieved at the cost of a very slow growing trout population. Most of the crayfish production is not utilized as trout food but enters the non-predatory pool of detrital organic matter. Key words: Orconectes virilis, brook trout, predation, production growth, mortality

Integrating the effects of fish exploitation and interspecific competition into current life history theories: an example with lacustrine brook trout (Salvelinus fontinalis) populations

2005 ◽  
Vol 62 (4) ◽  
pp. 747-757 ◽  
Author(s):  
Pierre Magnan ◽  
Raphaël Proulx ◽  
Michel Plante
Keyword(s):  
Life History ◽  
Interspecific Competition ◽  
Brook Trout ◽  
Reproductive Effort ◽  
Salvelinus Fontinalis ◽  
Adult Survival ◽  
Age At Maturity ◽  
Early Maturity ◽  
Fish Exploitation ◽  
Males And Females

We used data from 17 populations of lacustrine brook trout (Salvelinus fontinalis) of the Canadian Shield, southern Quebec, to test whether early maturity (in males and females) and high reproductive effort (in females) are associated with increased (i) fish exploitation (sportfishing) and (ii) interspecific competition through their effects on growth and survival. The age at maturity of males and females was inversely related to the intensity of both fishing and interspecific competition. Fishing and interspecific competition affect the age at maturity through their effect on adult survival but not on growth, supporting predictions of life history models based on survival. In contrast, we did not find consistent effects of interspecific competition and fishing on the gonadosomatic index of females, which was directly related to survival (in all populations) and to the age at maturity (in exploited populations). These latter results are contrary to the predictions of life history models under the assumption that survival is directly related to growth rate. Our results suggest that reproductive effort and age at maturity are not dependent on growth when survival is independent of growth, as is the case in exploited and sympatric populations experiencing low adult survival but high growth.

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