References of "Hydrobiologia"
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See detailEffect of land use on pollution status and risk of fish endocrine disruption in small farmland ponds
Mandiki; Gillardin; Martens et al

in Hydrobiologia (2014), 723

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See detailDiet overlap between the newly introduced Lamprichthys tanganicanus and the Tanganyika sardine in Lake Kivu, Eastern Africa
Masilya, M. P.; Darchambeau, François ULg; Isumbisho, M. et al

in Hydrobiologia (2011), 675(1), 75-86

This study evaluates the possible competition for food between Lamprichthys tanganicanus, recently introduced in Lake Kivu, and Limnothrissa miodon, which has been the basis of the pelagic fishery in this ... [more ▼]

This study evaluates the possible competition for food between Lamprichthys tanganicanus, recently introduced in Lake Kivu, and Limnothrissa miodon, which has been the basis of the pelagic fishery in this lake for several decades. Since 2006, L. tanganicanus has expanded in the lake and its numbers have increased in the captures, raising concern for the sardine fishery. We carried out a 2-year monthly survey, based on experimental captures in littoral and pelagic stations, which demonstrated the invasive dispersal of L. tanganicanus in littoral and pelagic waters. The diet of both species was determined on the basis of gut content analyses, taking into account the influence of site and season, and a diet overlap index was calculated. In the pelagic zone, where almost all size classes of both species were present and essentially fed upon mesozooplankton, the diet overlap was high. This situation stems from the fact that L. tanganicanus has colonized the pelagic zone in Lake Kivu, likely in search for more abundant mesozooplankton. Inshore, the diet overlap between the two species was lower, as L. tanganicanus consumed a broad range of food, whereas L. miodon strongly selected insects and, chiefly for the largest specimens, fishes. These results suggest a likelihood of interspecific competition, particularly offshore, where mesozooplankton is the main available food type, and call for further monitoring of the sardine fishery, to assess a possible impact of the invader. © 2011 Springer Science+Business Media B.V. [less ▲]

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See detailLate Holocene environmental changes inferred from diatom, chironomid, and pollen assemblages in an Andean lake in Central Chile, Lake Laja (36°S)
Urrutia, Roberto; Araneda, Alberto; Torres, Laura et al

in Hydrobiologia (2010), 648

A sediment core encompassing the last 2000 years was extracted from Lake Laja, Chile, (36°54′S, 71°05′W) using an Uwitec drilling platform. The sediment was subsampled for loss on ignition, nutrients ... [more ▼]

A sediment core encompassing the last 2000 years was extracted from Lake Laja, Chile, (36°54′S, 71°05′W) using an Uwitec drilling platform. The sediment was subsampled for loss on ignition, nutrients, biogenic silica, and biological proxies (diatoms, chironomids, pollen). The sedimentary profile was characterized by several coarse volcanic layers. Loss on ignition, nutrients, and biogenic silica showed an increasing trend that suggests a recent shift to a higher trophic status. Diatom assemblages also suggested higher nutrient content with increased abundances of Aulacoseira granulata, A. distans, and Asterionella formosa. At the same time, a marked change in the benthic and facultative planktonic taxa may be associated with cooling. This period of change coincides with the European Little Ice Age (LIA). The chironomid profile showed four key zones distinguished largely by changes in the abundance of Tanytarsini, Parachironomus, and Macropelopia. Like diatoms, chironomids also seemed to reflect a shift to higher trophic conditions in the upper part reflected by increasing abundance of taxa such as Tribelos/Phaenopsectra, Cricotopus/Orthocladius, and Ablabesmyia. The most striking feature in the chironomid assemblage is the abundance of Podonominae, Parapsectrocladius, and Limnophyes/Compterosmittia, which could be associated with a cold-dry period between 1500 and 1900 AD in Lake Laja (the period of the European LIA). Pollen assemblages indicated fluctuations in humidity through changes in Nothofagus dombeyi-type, Poaceae, and Ephedra, and we inferred a strong human impact over the last 100 years from the appearance of Plantago and increased levels of Poaceae and Asteraceae subf. Cichorioidae. Finally, the three proxies showed the occurrence of a cold-dry event in Lake Laja (~1550–1900 AD), which roughly coincides with the European LIA. However the data from this research, does not prove neither rejects the existence of the occurrence of the MWP in the central Andes. [less ▲]

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See detailLimnological variability and pelagic fish abundance (Stolothrissa tanganicae and Lates stappersii) in Lake Tanganyika
Plisnier, P. D.; Mgana, H.; Kimirei, I. et al

in Hydrobiologia (2009), 625(1), 117-134

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See detailMovement behaviour of the small benthic Rhine sculpin Cottus rhenanus (Freyhof, Kottelat & Nolte, 2005) as revealed by radio-telemetry and pit-tagging
Ovidio, Michaël ULg; Detaille, Aurelie; Bontinck, Charlotte et al

in Hydrobiologia (2009), 636(1), 119-128

From February 2006 to June 2007, we followed the movement patterns of the Rhine sculpin (Cottus rhenanus) by combining short-term radio-telemetry (n = 10 radio-tagged sculpin with a miniature 0.5-g ... [more ▼]

From February 2006 to June 2007, we followed the movement patterns of the Rhine sculpin (Cottus rhenanus) by combining short-term radio-telemetry (n = 10 radio-tagged sculpin with a miniature 0.5-g transmitter) and long-term individual (PIT-tag) mark-recapture (n = 452 PIT-tagged sculpin during six removal electric fishing operations) studies in a small tributary of the River Meuse, Belgium. During a 25- to 27-day period, the radio-tracked sculpin displayed various mobility patterns, showing frequent movement from one day to another and longitudinal home ranges from 7 to 46 m, with cumulative distances up to 149 m. During the mark-recapture study, most (99%) recaptured PIT-tagged individuals moved from their original 5-m long site, subsequently using longitudinal home ranges between 5 and 435 m (mean, 50 m; median, 20 m). The most common movement behaviour was alternation between upstream and downstream movements (62%), followed by directional upstream (26%) and directional downstream (11%) movement. Using the latest available techniques, this study builds on the current knowledge on the Cottus genus and closes gaps in the comprehension of sculpin movement and home range at a scale that had not been investigated to date. [less ▲]

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See detailRegulated discharge produces substantial demographic changes on four typical fish species of a small salmonid stream
Ovidio, Michaël ULg; Capra, Hervé; Philippart, Jean-Claude ULg

in Hydrobiologia (2008), 609

A hydroelectric power plant (HPP) started operation in December 2002 on the River Lhomme, (mean annual flow: 1.78 m(3) s(-1)supercript stop; mean annual water temperature: 9.9 degrees C). The new HPP ... [more ▼]

A hydroelectric power plant (HPP) started operation in December 2002 on the River Lhomme, (mean annual flow: 1.78 m(3) s(-1)supercript stop; mean annual water temperature: 9.9 degrees C). The new HPP bypasses the river over a length of 1.2 km. The minimum flow allowed in the bypassed section is currently fixed at 0.220 m(3) s(-1)supercript stop. Before the construction of the HPP, two contrasted 150-m-long reaches of the Lhomme were selected to estimate their total fish population abundance and to analyse their fish population dynamics. Electrofishing was carried out in each of these two reaches on 23 April 2002 in a natural flow situation to remove the fish. Other inventories were carried out in late April or early May in 2003, 2004, 2005 and 2006 in minimum flow conditions. The results revealed a prompt and severe decrease in the total fish biomass (up to 81% for grayling from 2002 to 2006) combined with severe changes in the fish community structure that were not observed in a reference site. The effects of the flow reduction varied considerably depending on the size of the individuals, the species concerned and their habitat availability, which was modelled using a classical physical habitat simulation (EVHA method). [less ▲]

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See detailWorkshop on rotifers in ecotoxicology
Snell, T. W.; Joaquim-Justo, Célia ULg

in Hydrobiologia (2007), 593

The aim of the workshop on rotifers in ecotoxicology was to stimulate discussions on new developments in the field. Discussions about the use of biomolecular tools indicate that gene expression analysis ... [more ▼]

The aim of the workshop on rotifers in ecotoxicology was to stimulate discussions on new developments in the field. Discussions about the use of biomolecular tools indicate that gene expression analysis with rotifers should be available in the next few years. Such analyses will be a great asset as they enable ecotoxicologists to study molecular mechanisms of toxicity. Rotifers also appear as useful tools in the risk assessment of pharmaceuticals and their metabolites that find their way into aquatic ecosystems because their sensitivity to some of these substances is higher than that of cladocerans and algae. The nature and extent of the impact of potential endocrine disruptors on aquatic invertebrates is another poorly resolved issue for which rotifers are a promising tool. Indeed, rotifers seem to be particularly sensitive to androgenic and anti-antiandrogenic substances, whereas copepods and cladocerans are typically more affected by estrogens and juvenile hormone-like compounds. Besides their usefulness in these emerging fields of aquatic ecotoxicology, it was emphasized that research with rotifers on basic issues like, e.g., toxicant interference with predation, competition, or interspecific and interclonal variation in ecotoxicological tests is still needed. [less ▲]

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See detailMobility of individual roach Rutilus rutilus (L.) in three weir-fragmented Belgian rivers
Geeraerts, Caroline; Ovidio, Michaël ULg; Verbiest, Hilde et al

in Hydrobiologia (2007), 582

Adult roach Rutilus rutilus (L.) (N = 24; 19.9-36.1 cm FL) from three highly fragmented Belgian rivers were tagged with surgically implanted radio transmitters. Their seasonal movements were observed from ... [more ▼]

Adult roach Rutilus rutilus (L.) (N = 24; 19.9-36.1 cm FL) from three highly fragmented Belgian rivers were tagged with surgically implanted radio transmitters. Their seasonal movements were observed from March to August 2004 (circum reproduction period) in river stretches delimited by two physical barriers. In the three rivers, roach displayed similar patterns of movements which were mainly influenced by the date of observation (movements increased in late April-May) and water temperature (travel distances were more important when water temperature ranged between 10 degrees C and 14 degrees C). Roach sometimes cleared physical obstacles. The mean distances travelled in each river were relatively short (max. 2.5 km) and mainly influenced by the length of the study reach, which was delimited by physical barriers. [less ▲]

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See detailC, N, P concentrations and requirements of flowering Posidonia oceanica shoots
Gobert, Sylvie ULg; Lejeune, Pierre; Lepoint, Gilles ULg et al

in Hydrobiologia (2005), 533

The carbon, nitrogen and phosphorus contents in flowering and nonflowering shoots were compared after an important flowering event occurred in the Posidonia meadow of the Bay of Calvi. The flower ... [more ▼]

The carbon, nitrogen and phosphorus contents in flowering and nonflowering shoots were compared after an important flowering event occurred in the Posidonia meadow of the Bay of Calvi. The flower formation caused a significant increase of C and a significant decrease of N concentrations in intermediate and adult leaves. Minimum daily requirements in mg shoot(-1) day(-1) of 3.4 and 4.8 of C, 0.09 and 0.09 N, 0.01 and 0.02 of P respectively for nonflowering and flowering shoots were calculated. It shows that additional quantities of C and P are required for the inflorescence elaboration. The unchanged quantity of N required by the shoot for the inflorescence elaboration and the significant modification of N concentration in intermediate and adult leaves suggests that N is limited in the environment and that an efficient resorption of N occurs from leaves to ensure the inflorescence formation. [less ▲]

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See detailGeochemical composition of sediments in the Scheldt
Bouezmarni, Mohamed ULg; Wollast, Roland

in Hydrobiologia (2005), 540(1-3), 155-168

Superficial sediments of the Scheldt estuary were collected with a Van Veen grab at 57 stations between Temse and Vlissingen. They were analysed for major elements (Si, Al, Fe, Ca, Mg, Na, K, Cinorg and ... [more ▼]

Superficial sediments of the Scheldt estuary were collected with a Van Veen grab at 57 stations between Temse and Vlissingen. They were analysed for major elements (Si, Al, Fe, Ca, Mg, Na, K, Cinorg and Corg) and trace metals (Cd, Pb, Cu, Zn, Cr, Ni, Co, Mn and Li). Factor analysis indicates that 44% of the variance can be explained by one factor which exhibits a high saturation for trace metals, organic matter, Al and Fe, all variables typical of fine mud. The high scores of this first factor are almost exclusively present in the upper estuary except for one area in front of Terneuzen. The second factor, which explains 23% of the variance, is typical of the carbonates and the third one (19% of the variance) is representative of the clay minerals. These two factors are more evenly distributed over the estuary. As usual, a strong influence of granulometry on the distribution of trace elements in the sediments was observed. Intercomparison of their composition within the Scheldt or with those of other aquatic systems requires thus a normalization procedure. This problem has been studied in detail by analysing various size fractions (63–16, 16–8, 8–4, <4 m) obtained by elutriation of the sample or by using a parameter characteristic of the fine fraction such as the concentration of a typical element (Al, Fe, Li, Corg). The normalization of trace metals allowed us to evaluate an enrichment factor of the trace elements in the estuarine deposits due to mans activities. In addition, it demonstrates the decrease of the anthropogenic impact on the composition of sediments by comparing the composition of sediments collected in 1976 and in 1994. [less ▲]

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See detailThe impact of small physical obstacles on upstream movements of six species of fish - Synthesis of a 5-year telemetry study in the River Meuse basin
Ovidio, Michaël ULg; Philippart, Jean-Claude ULg

in Hydrobiologia (2002), 483(1-3), 55-69

In the course of the 'Meuse Salmon 2000' programme, most weirs and dams (3-8 m in height) in the regulated River Meuse have been progressively equipped with new fishways in order to restore the free ... [more ▼]

In the course of the 'Meuse Salmon 2000' programme, most weirs and dams (3-8 m in height) in the regulated River Meuse have been progressively equipped with new fishways in order to restore the free circulation of all amphibiotic fish species. Nevertheless, fish entering into major spawning tributaries are still confronted with various kinds of physical obstacles of which the overall impact on fish migration has never been investigated. In order to test their ability to negotiate physical obstacles, 128 individuals of fish ( Salmo trutta, Thymallus thymallus, Salmo salar, Chondrostoma nasus, Barbus barbus and Esox lucius) were captured several weeks before their spawning migrations and tagged with radio-transmitters. They were tracked from 30 to 466 days in the River Ourthe and six spawning tributaries over the period October 1995 to June 2001. All obstacles recorded in this study have been classified according to their type and main characteristics (i.e. slope, length and height). Results indicated that most fish migrate during or outside the spawning period and that some small obstacles are not as insignificant as initially thought and can significantly disrupt and/or obstruct their upstream movements. There is a need to harmonize interests in the sustainable conservation of fish populations and the development of small-scale hydropower generation and tourism. [less ▲]

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See detailSeasonal variations of activity pattern of brown trout (Salmo trutta) in a small stream, as determined by radio-telemetry
Ovidio, Michaël ULg; Baras, Etienne; Goffaux, D. et al

in Hydrobiologia (2002), 470(1-3), 195-202

Nine brown trout (27.9-42.8 cm FL, 234-995 g) from the Aisne stream (Belgian Ardenne) were tagged with surgically implanted radio transmitters, and their activity patterns were studied at 10-min intervals ... [more ▼]

Nine brown trout (27.9-42.8 cm FL, 234-995 g) from the Aisne stream (Belgian Ardenne) were tagged with surgically implanted radio transmitters, and their activity patterns were studied at 10-min intervals during twenty-six 24-h cycles from October 1995 to May 1997. The duration and intensity of activity were mainly proportional to water temperature and day length but some differences appeared between individuals. The daily home range in summer was also 3.2 times longer than in winter, and was exploited 2.5 times more intensively. At all seasons, trout were most active at dusk, and seasonal variations in diel patterns consisted mainly in a progressive shift from more crepuscular activity in autumn and winter to more homogenous and intensive activity during spring and summer, but still with a predominance of activity at dusk. This relative consistency of activity rhythm throughout the year was interpreted within the context of foraging risk and efficiency, in view of the scarcity of predators in the Aisne stream, and of drifting macroinvertebrates being consistently more abundant at dusk at all times of the year. However, activity patterns varied substantially between individuals living in different microhabitats, including when fish were investigated on the same day. This suggests that activity patterns are also subordinated to local factors such as habitat structure or abundance of drifting prey. [less ▲]

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See detailTrophic diversiy within the eastern Weddell Sea amphipod community
Dauby, Patrick ULg; Scailteur, Yves; De Broyer, Claude

in Hydrobiologia (2001), 443

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See detailAnthesis effects on Posidonia oceanica (L.) Delile phenology in the Bay of Calvi (Corsica, Mediterranean Sea)
Gobert, Sylvie ULg; Defawe, Olivier; Lepoint, Gilles ULg et al

in Hydrobiologia (2001), 455

In Posidonia oceanica (L.) Delile, anthesis induces a decrease in the number of juvenile leaves resulting in a significant reduction in the number of leaves on the flowering shoots. All the leaves of the ... [more ▼]

In Posidonia oceanica (L.) Delile, anthesis induces a decrease in the number of juvenile leaves resulting in a significant reduction in the number of leaves on the flowering shoots. All the leaves of the flowering shoots are narrower than the leaves of nonflowering shoots. A modification of the leaf growth also appears in flowering shoots: the oldest leaves are longer and the leaves induced during or after anthesis are shorter. At 10 m depth, in the Bay of Calvi, anthesis lasts roughly 3 months and the flowering is induced 7 months before anthesis. [less ▲]

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See detailAquatic bryophyte assemblages along a gradient of regulation in the river Rhine
Vanderpoorten, Alain ULg; Klein, J. P.

in Hydrobiologia (2000), 410

A study of the zonation of the aquatic bryophyte assemblages from the Anterior Rhine to the Middle Rhine is presented. The typology obtained differs from the hydrogeoinorphological classification because ... [more ▼]

A study of the zonation of the aquatic bryophyte assemblages from the Anterior Rhine to the Middle Rhine is presented. The typology obtained differs from the hydrogeoinorphological classification because the correction of the river has led to the homogenization of habitats. Since the straightening of the river in the course of the 19th century, the embankments have created more stable habitats on which mountain species formerly characteristic of the rapids of the High Rhine appeared. During the 20th century, regulation, the construction of hydroelectric powerstations even the canalization of the river in Alsace. have caused a great change in water level. On the Upper Rhine, the rcgularisation of the water level .'allowed the appearance and the spread of strict hydrophytes such as Octodiceras fontanum which is now common between Rastatt and Bonn. Conversely, species characteristic of variable water levels decreased or disappeared. The industrial development along the river has caused water quality to severely decrease downstream of the industrial areas, hence the decrease or the disappearance of their primary flora in favour of pollution-tolerant assemblages. The former side channels of the Upper Rhine in France that have been disconnected from the main river and fed by groundwater since canalization, possess a bryophyte flora very similar to that of good quality waters in the upstream part of the High Rhine or in the Alpine Rhine. This flora is the last regional relic of a flora that has disappeared from the main channel due to water pollution. These refugia should consequently be preserved from the flooding of alluvial forests, part of the flood management program. [less ▲]

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See detailFauna vs flora contribution to the leaf epiphytes biomass in a Posidonia oceanica seagrass bed (Revellata Bay, Corsica).
Lepoint, Gilles ULg; Havelange, Stéphane; Gobert, Sylvie ULg et al

in Hydrobiologia (1999), 394

The epiphyte biomass of Posidonia oceanica (L.) Delile leaves is mainly related to the substrate leaf availability. It decreases with increasing depth and increases from winter to summer, following the ... [more ▼]

The epiphyte biomass of Posidonia oceanica (L.) Delile leaves is mainly related to the substrate leaf availability. It decreases with increasing depth and increases from winter to summer, following the leaf biomass changes. In Revellata Bay (Gulf of Calvi, Corsica), at shallow depth (10m in this study) where photophilous algae grow, the fixed epifauna biomass accounts for about one third of leaf epiphytes biomass. At deeper depths in the Revellata Bay (20 and 30m), where shade-tolerant algae are dominant among epiflora, epifauna may account for more than half the leaf epiphytes biomass. [less ▲]

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See detailCanonical variables of aquatic bryophyte combinations for predicting water trophic level
Vanderpoorten, Alain ULg; Palm, R.

in Hydrobiologia (1998), 386(1-3), 85-93

A method for predicting water quality by linear regression using aquatic bryophy te canonical variables as predictors is presented. An example of application in the Alsatian Rhine valley is developed. The ... [more ▼]

A method for predicting water quality by linear regression using aquatic bryophy te canonical variables as predictors is presented. An example of application in the Alsatian Rhine valley is developed. The /--squared obtained before and after cross-validation reached 0.68 and 0.58 for the standard deviation of temperatures, 0.55 and 0.46 for the logarithm of the mean concentrations of N-NH4+, 0.52 and 0.43 for the logarithm of the mean concentrations of N-NO3- and 0.38 and 0.31 for the logarithm of the mean concentrations of P-PO43-. Higher r-squared were not expected due to the broad physico-chemical ranges and the low diversity of genuine aquatic bryophytes. The predicted values of the mean concentrations of N-NH4+, P-PO43- and of the standard deviation of temperatures were often greater than the measured ones. The aquatic bryophytes integrate the sudden increase of the trophic level in oligotrophic streams during the floods of the main eutrophic river and testify to a higher trophic level than expected from regular physico-chemical analyses outside the flood period. Aquatic bryophytes are also affected by water quality in the long term and indicate pollutants other than those measured in current water quality. Other factors besides trophic level might influence the aquatic bryophyte assemblages and should be monitored in order to find the precise relationships between water quality and aquatic macrophytes and in order to create a more accurate model of the effects of the flooding of disconnected streams by the Rhine waters (currently in progress in the Upper Rhine) on the aquatic macrophyte assemblages. [less ▲]

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See detailEnvironmental unpredictability rules the autumn migration of brown trout (Salmo trutta L.) in the Belgian Ardennes
Ovidio, Michaël ULg; Baras, Etienne; Goffaux, Delphine et al

in Hydrobiologia (1998), 372

This telemetry study aimed to document the mobility of Salmo trutta in the River Ourthe sub-basin (tributary of the River Meuse) during summer and autumn, and to analyse the environmental factors which ... [more ▼]

This telemetry study aimed to document the mobility of Salmo trutta in the River Ourthe sub-basin (tributary of the River Meuse) during summer and autumn, and to analyse the environmental factors which trigger spawning migration or limit their extension. Nine trout (233-2217 g and 26.6-55.2 cm FL) were radio-tagged with intraperitoneal radio transmitters and positioned daily, from 14 August 1996 to 15 January 1997. Until 1 October, fish showed restricted movements: daily journeys never exceeded 300 m and corresponded to displacements by high floods or to routine home range movements. From 7 October to 15 November, seven of the nine trout travelled upstream over distances from 5.6 to 22.95 km, into tributaries and sub-tributaries. Migration speed was fast during the early days, when trout could travel over more than 5 km per night, then progressively decreased as they were approaching putative spawning redds under lower temperature. Both ire the River Ourthe and in the Aisne stream, all migrations started within less than three weeks (early October) and were found to be triggered by the combination of three environmental factors: high variations of water temperature and water level between consecutive days, within a thermal range of 10-12 degrees C. From the trout point's of view, these may be signs that the environment becomes unpredictable, as its variability increases within a thermal range which no longer enables them to achieve high growth rates. These results are discussed within the context of foraging strategies, life history strategies and management of trout population. [less ▲]

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