Using 137Cs to measure and compare bioenergetic budgets of juvenile Atlantic salmon (Salmo salar) and brook trout (Salvelinus fontinalis) in the field

1999 ◽  
Vol 56 (5) ◽  
pp. 875-887 ◽  
Author(s):  
S Tucker ◽  
J B Rasmussen

Through the 137Cs mass balance method, annual consumption rates were estimated for juvenile Atlantic salmon (Salmo salar) parr and precocious males as well as for brook trout (Salvelinus fontinalis) at four sites in the Ste-Marguerite River system, Québec. With explicit age analysis, consumption rates and growth rates were derived on an individual fish and age-class basis. These represent the first consumption estimates for Atlantic salmon in the wild. Precocious males had consumption rates 1.5 times greater than nonmaturing parr, while Atlantic salmon parr consumption rates were 2.7 times greater than brook trout. There was a strong positive relationship between individual annual consumption and growth rates for Atlantic salmon and brook trout at all sites. Subsequently the concept of field maintenance ration was introduced as the intercept of consumption over growth. Maintenance rations for Atlantic salmon parr ranged from 0.010 to 0.016 g·g-1·day-1 between sites. Brook trout had maintenance rations approximately half those of Atlantic salmon at 0.0059 g·g-1·day-1. Precocious male growth efficiencies were half those of nonmaturing parr despite higher feeding and growth rates. Brook trout growth efficiencies were significantly greater than those of Atlantic salmon parr. The lower growth efficiencies observed for Atlantic salmon are likely due to increased metabolic costs associated with higher activity. On average, Atlantic salmon parr spent 2.4-fold more energy in activity than brook trout. Atlantic salmon precocious males spent 1.7 times more energy in activity than parr.

2001 ◽  
Vol 58 (8) ◽  
pp. 1672-1682 ◽  
Author(s):  
Zhongyan Weng ◽  
Nandita Mookerji ◽  
Asit Mazumder

The impact of a major flood and recovery of the stream communities under contrasting nutrient conditions were studied in two second-order streams of Sainte-Marguerite River, Quebec. A massive flood during the summer of 1996 caused extensive displacement of the stream substratum and severe reductions in the abundance of all biota: periphyton, benthic invertebrates, juvenile Atlantic salmon (Salmo salar), and brook trout (Salvelinus fontinalis) (especially in the 0+ age-class). In the postflood recovery phase, nutrient-enriched sections recovered significantly more rapidly than the nonenriched sections. After 1 month, periphyton biomass in the enriched sections had increased to five times that of the preflood levels, and after 2 months, the invertebrate communities had recovered to preflood levels. Fish densities and growth rates also returned to normal levels more rapidly in the enriched sections. Our results suggest that nutrient-rich systems are more resilient to massive disturbances, and so, nutrient enrichment may represent a viable tool for restoring nutrient-limited systems.


1975 ◽  
Vol 32 (9) ◽  
pp. 1652-1656 ◽  
Author(s):  
R. John Gibson ◽  
G. Power

Salmon parr and small brook trout were observed in two stream tanks providing choices of cover. One tank was shallow (24–29 cm) and the other deep (43–50 cm). In the shallow tank brook trout occurred most frequently in shade. When salmon were the sole species, they were most frequently in shade, but were mostly away from shade in the presence of trout. This selection for shade was not evident by either species in the deep tank.


1983 ◽  
Vol 40 (5) ◽  
pp. 647-652 ◽  
Author(s):  
E. L. Dalley ◽  
C. W. Andrews ◽  
J. M. Green

The incidence of sexual precocity in male Atlantic salmon parr (Salmo salar) was examined in selected rivers in insular Newfoundland from 1974 to 1977. The incidence was variable but generally high, particularly in eastern rivers. Examination of age-specific lengths revealed that the faster growing males became precocious but percent precocity for these varied among river systems. Precocity did not influence growth of parr in comparison to immatures up to the smolt stage. No difference was found in the condition (using gutted weights) of mature and immature parr. However, condition deteriorated in precocious fish compared to immature fish with smoltification. Parr sex ratios frequently differed significantly from 1:1. Possible reasons are discussed in terms of sex related distribution patterns and mortality of precocious parr. From smolt runs examined, it appears that too few precocious parr migrate as smolt to contribute to the grilse population. As a result of the high mortality, rivers with a high percentage of sexually precocious males tend to have a corresponding high percentage of adult females.


1968 ◽  
Vol 25 (11) ◽  
pp. 2321-2326 ◽  
Author(s):  
G. L. Greer ◽  
U. Paim

As indicated by thin-layer chromatography, hatchery-reared Atlantic salmon parr degraded DDT, absorbed from aqueous suspensions, to DDE and TDE within 9 hr. DDT adsorbed on external surfaces of the salmon was not degraded.


2018 ◽  
Vol 75 (11) ◽  
pp. 1949-1959
Author(s):  
Scott D. Roloson ◽  
Kyle M. Knysh ◽  
Michael R.S. Coffin ◽  
Karen L. Gormley ◽  
Christina C. Pater ◽  
...  

The purpose of this study was to update rainbow trout (Oncorhynchus mykiss) invasion status, delineate factors that increase the invasion probability, and quantify habitat overlap between invasive rainbow trout and native Atlantic salmon (Salmo salar) and brook trout (Salvelinus fontinalis) on Prince Edward Island, Canada. Analysis of landscape-level variables in 26 watersheds (14 with and 12 without rainbow trout) demonstrated that watershed slope, percent agricultural land use, and distance to the nearest rainbow trout population significantly increased the probability of rainbow trout establishment. Two independent reach-level fish community surveys were conducted by electrofishing in combination with habitat surveys. Reaches with rainbow trout had higher stream slope, Atlantic salmon were found in wider reaches with larger substrate, and brook trout were typically dominant in headwater reaches with finer substrate. Findings at multiple ecological scales illustrated that rainbow trout invasion success is positively influenced by the presence of high-slope habitat. Habitat separation of the three salmonid species indicates that competition with introduced rainbow trout may not be the most significant threat to native salmonid populations.


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