Top-Down Effects of Brook Trout (Salvelinus fontinalis) in a Boreal Forest Stream

1992 ◽  
Vol 49 (10) ◽  
pp. 2093-2103 ◽  
Author(s):  
José A. Bechara ◽  
Guy Moreau ◽  
Dolors Planas

The impact of fish predation on epibenthic organisms at different trophic levels was studied in a series of replicated experimental outdoor channels fed by a boreal forest stream (Québec, Canada). Brook trout (Salvelinus fontinalis) were introduced into five of 10 channels according to a randomized block experimental design. Periphyton biomass (expressed as total chlorophyll a and total organic matter) and macroinvertebrate biomass were measured four times during the summer. The biomass of small insects such as Chironomidae was always higher in the presence than in the absence of fish, while the biomass of larger invertebrates such as Baetis (Ephemeroptera) and Psychoglypha subborealis (Trichoptera) was reduced in the presence of fish. Periphyton biomass was significantly greater in channels with fish on the first sampling date after fish introduction but not at later dates. Complementary cage experiments, involving both the inclusion and exclusion of selected invertebrates from periphyton-covered surfaces, demonstrated that the presence of Baetis can reduce the periphytic biomass, while the presence of P. subborealis can reduce the biomass of Chironomidae. Overall, these results suggest that size-selective predation by brook trout can cause profound changes in the structure of epibenthic communities at primary as well as secondary trophic levels.


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.



2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Alexandre Bérubé Tellier ◽  
Paul E. Drevnick ◽  
Andrea Bertolo

<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>



1995 ◽  
Vol 52 (8) ◽  
pp. 1733-1740 ◽  
Author(s):  
R. Allen Curry ◽  
David L. G. Noakes

Spawning areas selected by brook trout (Salvelinus fontinalis) displayed variable relationships to discharging groundwater across geologic regions. In Canadian Shield waters, spawning was associated with areas of distinct, discharging groundwater. The specific mechanism of selection could not be determined. Groundwater did not appear to influence the selection of individual redd sites within these discharge areas. Competition among females for the opportunity to spawn in a limited area defined by the discharging groundwater appeared to control the selection of redd sites. In southwestern Ontario streams, discharging groundwater was prominent throughout areas of spawning both at redds and at adjacent, nonspawning substrates (≤7 m). Consequently, relationships between groundwater and spawning site selection were ambiguous. On the unglaciated plateau of central Pennsylvania, no groundwater was observed in redds or nonspawning substrates in streams. Brook trout management programmes must consider these groundwater relationships and therefore the impact of land use on groundwater quality and quantity.



1990 ◽  
Vol 47 (12) ◽  
pp. 2278-2284 ◽  
Author(s):  
Stephanie Lachance ◽  
Pierre Magnan

Wild and hybrid strains of brook trout, Salvelinus fontinalis, showed better rates of recovery (by angling) and yield (kilograms of fish recovered per kilogram planted) than a domestic strain, during the 2 yr following planting, in six small oligotrophic lakes of the Laurentian Shield. Native brook trout and white sucker, Catostomus commersoni, had a significant impact on planted brook trout. Recovery, percent of increment in weight and yield of each planted strain were inversely correlated with (1) the relative abundance of native brook trout, and (2) the occurrence of white sucker, supporting hypotheses of intra- and interspecific competition. Furthermore, the response variables were also inversely correlated with the number of potential competitors, indicating that the impact of native brook trout and white sucker was additive. The recovery in number of planted trout (both years and all strains) was approximately four times higher in lakes with effectively no competitors than in lakes containing both white sucker and native brook trout; the increase in weight was nearly three times higher, and the yield was more than nine times higher. The performances of planted fish were intermediate in the lake containing only native brook trout as competitor.





1996 ◽  
Vol 74 (7) ◽  
pp. 1304-1312 ◽  
Author(s):  
Nicole Dubois ◽  
Pierre Magnan ◽  
David J. Marcogliese

White sucker, Catostomus commersoni, has been introduced in many brook trout, Salvelinus fontinalis, lakes of the Laurentian Shield, Quebec, Canada. The goal of this study was to assess the impact of these introductions on the parasite fauna of brook trout. Three lakes containing brook trout only and three lakes containing both brook trout and white sucker were studied. The objectives were (i) to determine if white sucker parasites were able to colonise the relatively oligotrophic lakes of the Laurentian Shield, (ii) to establish if parasites were exchanged between sucker and trout, and (iii) to study the effect of trout feeding habits on their parasite fauna, since this fish shifts its diet from zoobenthos to Zooplankton when living with white sucker. Eight of the 12 parasite species found on white sucker probably colonised the lakes with their host. Among the 11 parasite species identified from trout, it is unlikely that any were introduced by white sucker. Trout living with white sucker have more parasites transmitted by Zooplankton (Diphyllobothrium ditremum and Eubothrium salvelini) and fewer parasites transmitted by zoobenthos (Crepidostomum farionis and Sterliadochona ephemeridarum) than trout living in allopatry. Local factors such as lake morphometrics also seemed to play an important role in the composition of the trout parasite fauna.



2019 ◽  
Vol 35 (2) ◽  
pp. 403-420
Author(s):  
Spencer A. Bruce ◽  
Scott D. George ◽  
Barry P. Baldigo ◽  
Jeremy J. Wright


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anna Åkesson ◽  
Alva Curtsdotter ◽  
Anna Eklöf ◽  
Bo Ebenman ◽  
Jon Norberg ◽  
...  

AbstractEco-evolutionary dynamics are essential in shaping the biological response of communities to ongoing climate change. Here we develop a spatially explicit eco-evolutionary framework which features more detailed species interactions, integrating evolution and dispersal. We include species interactions within and between trophic levels, and additionally, we incorporate the feature that species’ interspecific competition might change due to increasing temperatures and affect the impact of climate change on ecological communities. Our modeling framework captures previously reported ecological responses to climate change, and also reveals two key results. First, interactions between trophic levels as well as temperature-dependent competition within a trophic level mitigate the negative impact of climate change on biodiversity, emphasizing the importance of understanding biotic interactions in shaping climate change impact. Second, our trait-based perspective reveals a strong positive relationship between the within-community variation in preferred temperatures and the capacity to respond to climate change. Temperature-dependent competition consistently results both in higher trait variation and more responsive communities to altered climatic conditions. Our study demonstrates the importance of species interactions in an eco-evolutionary setting, further expanding our knowledge of the interplay between ecological and evolutionary processes.



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