Seasonal growth of wild Atlantic salmon juveniles and implications on age at smoltification

The seasonal growth trajectories of wild Atlantic salmon Salmo salar juveniles by age group within the Margaree River, Canada, are described. Circuli counts from scales were used to infer growth rates at different ages and these were used to predict the proportions of age 2- and 3-year old smolts from different portions of the watershed. In the wild Atlantic salmon juveniles from the Margaree River, there was no bimodality in fork length frequencies and no 1 year old smolts were produced. Water temperature differences during the growing season were insufficient to explain the differences in growth rates and size at age among the sites sampled. There was a positive association between the growth rate in the first year and the subsequent age at smoltification. In the Margaree River, differences in tributary specific growth rates and size at age were expected to produce important differences in the relative ages at smoltification.

[1]  W. Gurney,et al.  Seasonal patterns of growth, expenditure and assimilation in juvenile Atlantic salmon , 2002 .

[2]  R. Saunders,et al.  Influence of Photoperiod on Growth of Juvenile Atlantic Salmon and Development of Salinity Tolerance during Winter–Spring , 1990 .

[3]  F. Huntingford,et al.  Behavioural influences on life-history variation in juvenile Atlantic salmon, Salmo salar , 1992, Environmental Biology of Fishes.

[4]  D. C. Bowden,et al.  Long-Term Effects of Electrofishing on Growth and Body Condition of Brown Trout and Rainbow Trout , 1997 .

[5]  J. M. Elliott,et al.  A functional model for maximum growth of Atlantic Salmon parr, Salmo salar, from two populations in northwest England , 1997 .

[6]  E. Niemelä,et al.  Growth differences between the Atlantic salmon parr,Salmo salar, of nursery brooks and natal rivers in the River Teno watercourse in northern Finland , 1995, Environmental Biology of Fishes.

[7]  R. J. Gibson.  The Atlantic salmon in fresh water: spawning, rearing and production , 1993, Reviews in Fish Biology and Fisheries.

[8]  A. Nicieza,et al.  Development of length-bimodality and smolting in wild stocks of Atlantic salmon, Salmo salar L., under different growth conditions , 1991 .

[9]  J. Post,et al.  Effects of Pulsed and Continuous DC Electrofishing on Juvenile Rainbow Trout , 1998 .

[10]  R. G. Randall,et al.  Growth, biomass, and production of juvenile Atlantic salmon (Salmo salar L.) in two Miramichi River, New Brunswick, tributary streams , 1982 .

[11]  G. Leonard,et al.  Survival, Growth, and Smolt Production of Atlantic Salmon Stocked as Fry in a Southern New England Stream , 1994 .

[12]  R. Cunjak,et al.  Implications of territory size for the measurement and prediction of salmonid abundance in streams , 1998 .

[13]  N. Metcalfe,et al.  A framework for understanding Atlantic salmon (Salmo salar) life history , 1998 .

[14]  Neil B. Metcalfe,et al.  Determinants of geographical variation in the age of seaward-migrating salmon, Salmo salar , 1990 .

[15]  R. Borgstrøm,et al.  Effect of habitat types on survival, spatial distribution and production of an allopatric cohort of Atlantic salmon, Salmo salar L., under conditions of low competition , 1991 .

[16]  N. Metcalfe.  The interaction between behavior and physiology in determining life history patterns in Atlantic salmon (Salmo salar) , 1998 .

[17]  Marc Mangel,et al.  Modelling the proximate basis of salmonid life-history variation, with application to Atlantic salmon, Salmo salar L. , 2004, Evolutionary Ecology.

[18]  R. G. Randall.  Emergence, population densities, and growth of salmon and trout fry in two New Brunswick streams , 1982 .

[19]  J. Dempson,et al.  Relative production of Atlantic salmon from fluvial and lacustrine habitats estimated from analyses of scale characteristics , 1996 .

[20]  Francis Juanes,et al.  Ecology of stream fish: insights gained from an individual-based approach to juvenile Atlantic salmon , 2000 .

[21]  R. White,et al.  Effect of Backpack Electroshock on Westslope Cutthroat Trout Injury and Growth 110 and 250 Days Posttreatment , 2001 .

[22]  M. Mangel.  Climate change and salmonid life history variation , 1994 .

[23]  J. Thorpe.  Bimodal distribution of length of juvenile Atlantic salmon (Salmo salar L.) under artificial rearing conditions , 1977 .

[24]  J. Thorpe,et al.  Evidence for adaptive matching of appetite in juvenile Atlantic salmon (Salmo solar) with regular seasonal rhythms of food availability , 1997 .

[25]  Timing of habitat shift by Atlantic salmon parr from fluvial to lacustrine habitat: analysis of age distribution, growth, and scale characteristics , 1998 .

[26]  Application of a fry (0+;) abundance index, based on semi-quantitative electrofishing, to predict Atlantic salmon smolt runs in the River Bush, Northern Ireland , 1995 .

[27]  Arne J. Jensen,et al.  Is there a threshold size regulating seaward migration of brown trout and Atlantic salmon , 1993 .