Habitat Profitability and Choice in a Sit-And-Wait Predator: Juvenile Salmon Prefer Slower Currents on Darker Nights

Metcalfe, Neil B.; Valdimarsson, Sveinn K.; Fraser, Neil H. C.

doi:10.2307/6002

Cited by 78 publications

(52 citation statements)

References 32 publications

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“…Salmon in this study apparently choose positions with higher than average snout velocities, possibly to gain access to higher rates of invertebrate drift and increase their potential energy gain. Furthermore, boulders can also provide excellent feeding areas by funnelling the current, increasing the rate of invertebrate drift, and increasing the growth rate potential of a site (Metcalfe et al, 1997;Mitchell et al, 1998). To understand how juvenile salmonid microhabitat use relates to invertebrate drift, it would be necessary to follow focal fish to examine the interplay between velocity, invertebrate drift, and salmonid growth and survival.…”

Section: Discussionmentioning

confidence: 99%

Assessing the effect of visual isolation on the population density of Atlantic salmon (Salmo salar) using GIS

Dolinsek¹,

Biron²,

Grant³

2007

River Research & Apps

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Few studies investigate the behavioural response of organisms to stream enhancement schemes. One behavioural process that is rarely examined in enhancement studies is the visual isolation created by adding boulders on the river bed. The objective of this research is to use a Geographic Information Systems (GIS) viewshed analysis to determine if the increase in density of Atlantic salmon observed in boulder-added zones is related to visual isolation or, alternatively, the presence of a velocity refuge. Eight study sites were established on Catamaran Brook and Little Southwest Miramichi River (New Brunswick, Canada). Each reach was divided into three quadrats of 3 m Â 2 m. In one of the quadrats, 36 boulders (D 50 ¼ 0.20 m) were added to increase visual isolation. Boulders were removed from another adjacent quadrat whereas a third quadrat was left in a natural state. A detailed Digital Elevation Model (DEM) was created for all the sites with a total station. Atlantic salmon were observed by snorkelling on several occasions during two summers. Their position was recorded with the total station and the snout and average velocity was measured. A GIS viewshed analysis was performed to determine the visible area for each fish and to verify whether the surrounding fish were visible or not. Results suggest that the primary mechanism responsible for the observed increase in Atlantic salmon population density in the experimental quadrats is a reduction in the field of view of individuals, through an increase in habitat heterogeneity, which is consistent with the visual isolation hypothesis. There was also no change in the snout velocity of salmon among the three treatments, suggesting that the increase in density is not consistent with the velocity-refuge hypothesis.

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Section: Discussionmentioning

confidence: 99%

Assessing the effect of visual isolation on the population density of Atlantic salmon (Salmo salar) using GIS

Dolinsek¹,

Biron²,

Grant³

2007

River Research & Apps

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“…Lunar illumination and lunar phase affect fish species in multiple manners, including visual detection of prey and predator camouflage, and may change fish distribution, thermal exposure, and activity patterns (Metcalfe et al 1997, Hanson et al 2008, Aarestrup et al 2009, Afonso & Hazin 2015, Papastamatiou et al 2015, Schabetsberger et al 2015. Shark prey species may modify vertical distributions according to the lunar phase (Schabetsberger et al 2013(Schabetsberger et al , 2015, suggesting that lunar phase (and illumination) influences the distribution of foraging sharks.…”

Section: Ecologymentioning

confidence: 99%

Spatial ecology of blue shark and shortfin mako in southern Peru: local abundance, habitat preferences and implications for conservation

Adams¹,

Flores²,

Flores³

et al. 2016

Endang. Species. Res.

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“…However, Atlantic salmon have been shown to change foraging strategies below light levels of 10 À1 lux, moving to areas of slow-moving water that, while not as rich in prey, allow more time for identification of prey items and night-time foraging (Metcalfe et al 1997). Light adaptations are also evident in lentic environments, where zooplankton engage in DVM in the water column to feed on phytoplankton during the night when they are less visible to predators (Young and Watt 1996).…”

Section: Ecosystem Functioningmentioning

confidence: 99%

The influence of artificial light on stream and riparian ecosystems: questions, challenges, and perspectives

et al. 2011

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Abstract. Artificial light at night is gaining attention for its potential to alter ecosystems. Although terrestrial ecologists have observed that artificial light at night may disrupt migrations, feeding, and other important ecological functions, we know comparatively little about the role artificial light might play in disrupting freshwater and riparian ecosystems. We identify and discuss four future research domains that artificial light may influence in freshwater and associated terrestrial ecosystems, with an emphasis on running waters: (1) dispersal, (2) population genetics and evolution, (3) ecosystem functioning, and (4) potential interactions with other stressors. We suggest that future experimental and modeling studies should focus on the effects of different spectral emissions by different light sources on freshwater organisms, the spatial and temporal scale over which artificial light acts, and the magnitude of change in light at night across the landscape relative to the distribution of running and standing waters. Improved knowledge about the effects of artificial light on freshwater ecosystems will inform policy decisions about changes to artificial light spectral emissions and distributions.

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Habitat Profitability and Choice in a Sit-And-Wait Predator: Juvenile Salmon Prefer Slower Currents on Darker Nights

Cited by 78 publications

References 32 publications

Assessing the effect of visual isolation on the population density of Atlantic salmon (Salmo salar) using GIS

Assessing the effect of visual isolation on the population density of Atlantic salmon (Salmo salar) using GIS

Spatial ecology of blue shark and shortfin mako in southern Peru: local abundance, habitat preferences and implications for conservation

The influence of artificial light on stream and riparian ecosystems: questions, challenges, and perspectives

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