Variability in stream water chemistry and brown trout ( Salmo trutta L.) parr otolith microchemistry on different spatial scales

Field studies were conducted to examine intra- and inter-individual diet variation in subpopulations of brown trout (Salmo trutta) at different spatial scales (between sites, between habitats (riffle and pool) within a site, and between individuals within a habitat) and different temporal scales (within subpopulations and within individuals over time) at four sites in the Glenfinish River, County Cork, Ireland. Electrofishing and stomach flushing techniques were used whereby fish larger than 85 mm were uniquely coded, allowing for repeated capture and diet analysis of individuals. A considerable degree of variation within and between subpopulations and individual diets was apparent. On the basis of novel and recent graphical models of feeding strategies, the trend was for a generalized strategy amongst trout subpopulations occupying riffles throughout most seasons, whilst specialization tended to be more frequent amongst trout occupying pools during summer and autumn. Using similarity indices and dendrograms, we illustrate that individual fish showed both feeding strategies within one habitat over time.

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Brown trout (Salmo trutta) growth and condition along a winter thermal gradient in temperate streams

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2016-0005 ◽

2017 ◽

Vol 74 (1) ◽

pp. 56-64 ◽

Cited By ~ 2

Author(s):

W.E. French ◽

B. Vondracek ◽

L.C. Ferrington ◽

J.C. Finlay ◽

D.J. Dieterman

Keyword(s):

Water Temperature ◽

Brown Trout ◽

Thermal Regime ◽

Salmo Trutta ◽

Stream Water ◽

Juvenile Fish ◽

Late Winter ◽

Caloric Density ◽

Significant Difference ◽

Brown Trout Salmo Trutta

Winter harshness and the degree to which it can impact stream-dwelling salmonid populations has received considerable attention from fisheries biologists, although some debate exists regarding the importance of winter severity for local populations. Groundwater input may buffer stream water temperature and benefit fish in buffered versus unbuffered streams. Overwinter growth and condition of individual brown trout were measured in 24 groundwater-dominated streams, and the relations between winter growth and condition to stream thermal regime (quantified by regressions of air and water temperature) and diet quality (amount and caloric density of prey) were examined in a subset of 16 streams. Brown trout (Salmo trutta) growth rate (mg·g−1·day−1) was positive overwinter in 18 of 24 streams, and there was no significant change in condition between early and late winter. Juvenile fish grew faster than adults, but there was no significant difference in condition between adults and juveniles. Thermal regime positively influenced winter growth for both adults and juveniles, likely mediated through moderation of water temperature by groundwater, whereas diet had no significant effect on growth.

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Brown Trout (Salmo trutta) Status and Chemistry from the Norwegian Thousand Lake Survey: Statistical Analysis

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f93-066 ◽

1993 ◽

Vol 50 (3) ◽

pp. 575-585 ◽

Cited By ~ 35

Author(s):

Arthur J. Bulger ◽

Leif Lien ◽

B. J. Cosby ◽

Arne Henriksen

Keyword(s):

Water Chemistry ◽

Brown Trout ◽

Salmo Trutta ◽

Aluminum Concentration ◽

Historical Trends ◽

Trout Population ◽

Brown Trout Salmo Trutta ◽

Discriminant Analyses ◽

Individual Variables ◽

Negative Impacts

Substantial negative impacts of acidic precipitation on freshwater fishes have been recorded over the last 50 yr in Norway. We analyzed the present status and historical trends of brown trout (Salmo trutta) populations in relation to water chemistry in 584 Norwegian lakes. Since the 1940s, 39% of the lakes have lost their trout populations, and another 17% of the lakes have declining trout populations; thus, 56% of the populations have been adversely affected. The results of analysis of variance, principal components analysis, and discriminant analyses converge on the variables pH, monomeric inorganic aluminum, and alkalinity as most strongly related to trout status. Lakes whose trout populations are extinct have an average aluminum concentration of 133 μg/L, an alkalinity of −34 μeq/L, and a pH of 4.8 versus 11 μg Al/L, + 27 μeq/L, and 6.0 for lakes with healthy populations. Also, nitrate and sulfate levels are significantly higher in affected versus unaffected lakes. Calcium and sulfate appear to influence trout status moderately as individual variables, but strongly in combination, since they are the major determinants of alkalinity in these lakes. Models based on discriminant analyses showed good success (up to 89%) in predicting trout population status categories from water chemistry.

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Experimental evidence simultaneously confirms and contests assumptions implicit to otolith microchemistry research

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2013-0224 ◽

2014 ◽

Vol 71 (3) ◽

pp. 356-365 ◽

Cited By ~ 6

Author(s):

Geoff Veinott ◽

Peter A.H. Westley ◽

Craig F. Purchase ◽

Lucas Warner

Keyword(s):

Life History ◽

Maternal Effects ◽

Brown Trout ◽

Salmo Trutta ◽

Otolith Microchemistry ◽

Maternal Influence ◽

Elemental Concentrations ◽

The Core ◽

Chemical Signatures ◽

Brown Trout Salmo Trutta

Otolith microchemistry has become an integral fisheries tool, yet the utility of this tool hinges on the assumptions that (i) elements are temporally stable once deposited in the otolith and (ii) the influence of maternal effects are temporally limited. Here we test these assumptions by quantifying through time the chemical signatures from two families of brown trout (Salmo trutta), differing in maternal life history (i.e., mothers were either anadromous or nonanadromous). Concentrations of zinc, strontium, and barium were temporally stable in the core signatures between different aged siblings, but significant differences in the elemental concentrations of magnesium and manganese were detected. The Sr concentration (indicative of maternal influence) on the growing surface of otoliths converged briefly between families at 3–5 weeks post-emergence, but never stabilized during the course of the experiment. Taken together, these results both confirm and call into question assumptions implicit to otolith microchemistry research. To the extent that the patterns observed here are representative across species, caution is warranted when using otolith microchemistry to address certain types of ecological questions in nature.

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The strontium content of roe collected from spawning brown trout Salmo trutta L. reflects recent otolith microchemistry

Journal of Fish Biology ◽

10.1111/j.1095-8649.2008.01842.x ◽

2008 ◽

Vol 72 (7) ◽

pp. 1847-1854 ◽

Cited By ~ 6

Author(s):

E. M. Waite ◽

G. P. Closs ◽

J. Kim ◽

B. Barry ◽

A. Markwitz ◽

...

Keyword(s):

Brown Trout ◽

Salmo Trutta ◽

Otolith Microchemistry ◽

Strontium Content ◽

Brown Trout Salmo Trutta

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Life-history variation of two inland salmonids revealed through otolith microchemistry analysis

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2018-0087 ◽

2019 ◽

Vol 76 (11) ◽

pp. 1971-1981 ◽

Cited By ~ 1

Author(s):

Lindsy R. Ciepiela ◽

Annika W. Walters

Keyword(s):

Rainbow Trout ◽

Brown Trout ◽

Salmo Trutta ◽

Spatial Ecology ◽

Otolith Microchemistry ◽

Life History Variation ◽

Natal Origin ◽

Rainbow Trout Oncorhynchus Mykiss ◽

Spawning Site ◽

Brown Trout Salmo Trutta

Increasingly, otolith microchemistry analysis is used as a tool to trace fish migrations, especially migrations of diadromous fishes. Yet, few studies have used otolith microchemistry to trace migrations in small inland watersheds, leaving major knowledge gaps in our understanding of inland fish spatial ecology. Here, we evaluate the use of tributary habitat for spawning and describe and compare fluvial brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) natal origin distribution, time spent in natal streams, and spawning site fidelity. 63% of rainbow trout and 57% of brown trout migrated after hatching. Brown trout showed greater variation in time spent in natal tributaries, suggesting that individuals are temporally distributing risk among offspring. By contrast, rainbow trout showed greater variation in natal origin, suggesting that individuals are spatially distributing risk among offspring. Our results indicate there is high inter- and intraspecific migration variation in inland salmonid populations, which may be linked to access to a mosaic of spawning and rearing habitat types.

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