scholarly journals Occupancy of young-of-year Arctic grayling (Thymallus arcticus) in Barrenland streams

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Jared R. Ellenor ◽  
Peter A. Cott ◽  
Heidi K. Swanson
Keyword(s):  
Fish Species ◽  
Field Research ◽  
Open Water ◽  
Stream Habitat ◽  
Anthropogenic Effects ◽  
Lake Area ◽  
Arctic Grayling ◽  
Distributional Patterns ◽  
Baker Lake ◽  
Thymallus Arcticus

AbstractArctic grayling (Thymallus arcticus) is an iconic fish species that is present across the remote subarctic Barrenlands, yet our lack of understanding of their distributional patterns constrains predictions of anthropogenic effects on Barrenland populations. These adfluvial fish rely on seasonal lake-stream connections to migrate, spawn, and rear. We address knowledge gaps on what Barrenland stream attributes are suitable for rearing young-of-year Arctic grayling. Visual surveys of young-of-year Arctic grayling were conducted in 48 streams near Baker Lake, Nunavut, Canada. Occupancy modeling was used to relate stream habitat and landscape variables to fish presence/absence. The best predictors of occupancy were total area of contributing upstream lakes and landcover (upland/lowland); stream basins with larger contributing upstream lake area and more lowland cover were more likely to be occupied. Results suggest that occupancy reflects reliability of stream connectivity throughout the open water season and across years. The occupancy model developed here can adequately predict stream suitability for young-of-year Arctic grayling using lake area and land classification data that are remotely accessed. This may lessen the considerable financial and logistical constraints of conducting field research on Arctic grayling in the vast Barrenlands and facilitate more directed field programs to inform conservation and mitigation plans.

Energetic status and bioelectrical impedance modeling of Arctic grayling Thymallus arcticus in interior Alaska Rivers

2019 ◽  
Vol 102 (11) ◽  
pp. 1337-1349
Author(s):  
Jeffrey A. Falke ◽  
Lauren T. Bailey ◽  
Kevin M. Fraley ◽  
Michael J. Lunde ◽  
Andrew D. Gryska
Keyword(s):  
Bioelectrical Impedance ◽  
Arctic Grayling ◽  
Interior Alaska ◽  
Impedance Modeling ◽  
Thymallus Arcticus

Selection of Positions by Drift-Feeding Salmonids in Dominance Hierarchies: Model and Test for Arctic Grayling (Thymallus arcticus) in Subarctic Mountain Streams, Interior Alaska

1992 ◽  
Vol 49 (10) ◽  
pp. 1999-2008 ◽  
Author(s):  
Nicholas F. Hughes
Keyword(s):  
Bottom Topography ◽  
Lateral Diffusion ◽  
Distribution Patterns ◽  
Mountain Stream ◽  
Physical Habitat ◽  
Dominance Hierarchies ◽  
Arctic Grayling ◽  
Drift Feeding ◽  
Stream Salmonids ◽  
Thymallus Arcticus

In this work I describe a model to predict position choice by each individual in a dominance hierarchy of drift-feeding stream salmonids. This is an adaptation of Hughes and Dill's model (1990. Can. J. Fish. Aquat. Sci. 47: 2039–2048) of position choice by solitary fish. I have included the effect that prey consumption, lateral diffusion of drifting invertebrates, and entry of invertebrates into the drift have on the density of prey downstream of feeding fish and the restrictions that dominant fish place on freedom of choice by their subordinates. l assume that each fish chooses the most profitable position that its rank in the hierarchy will allow. There was an encouraging match between the distribution patterns predicted by the model and the distribution patterns actually adopted by Arctic grayling (Thymallus arcticus) in two pools of a mountain stream. This result suggests that Arctic grayling locate and rank positions based on their profitability. The predictions of reduced models, and the location of positions in relation to bottom topography and current flow, suggest that the physical habitat forms the template for distribution patterns by determining the location and ranking of the most profitable positions.

scholarly journals Consumption of Shrews, Sorex spp., by Arctic Grayling, Thymallus arcticus

2004 ◽  
Vol 118 (1) ◽  
pp. 111 ◽  
Author(s):  
Jonathan W. Moore ◽  
G. J. Kenagy
Keyword(s):  
Stable Isotopes ◽  
Dietary Habits ◽  
Riparian Zones ◽  
Stream Fishes ◽  
Nitrogen Stable Isotopes ◽  
Arctic Grayling ◽  
Thymallus Arcticus ◽  
Southwestern Alaska

In an investigation of the dietary habits of Arctic Grayling (Thymallus arcticus) we found that two individuals out of 93 sampled in southwestern Alaska (approximately 59°N, 159°W) contained a total of five shrews (Sorex spp.). These shrews contained enriched levels of nitrogen stable isotopes, suggesting utilization of nutrients derived from salmon. We hypothesize that normally terrestrial shrews accidentally enter streams while foraging along the productive riparian zones of creeks with high densities of salmon. Shrews are apparently susceptible to opportunistic predation by resident stream fishes, including Arctic Grayling, when they enter the streams.

Breeding Tubercles Occur on Male and Female Arctic Grayling (Thymallus arcticus)

Copeia ◽  
1978 ◽  
Vol 1978 (1) ◽  
pp. 185 ◽  
Author(s):  
L. F. Kratt ◽  
R. J. F. Smith
Keyword(s):  
Male And Female ◽  
Arctic Grayling ◽  
Thymallus Arcticus

Effects of an invasive bivalve (Dreissena polymorpha) on fish in the Hudson River estuary

2004 ◽  
Vol 61 (6) ◽  
pp. 924-941 ◽  
Author(s):  
David L Strayer ◽  
Kathryn A Hattala ◽  
Andrew W Kahnle
Keyword(s):  
Fish Species ◽  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
River Estuary ◽  
Open Water ◽  
Hudson River ◽  
Alosa Sapidissima ◽  
Median Increase ◽  
Littoral Species ◽  
Water Species

Despite predictions that the zebra mussel (Dreissena polymorpha) invasion of North America would damage fisheries, analyses of actual effects on fish have been few and equivocal. We analyze 26 years of data on fish populations in the Hudson River to quantify changes associated with the zebra mussel invasion. Based on our measurements of changes in the lower food web, we predicted that populations of open-water fish species (e.g., Alosa spp.) would suffer and populations of littoral fish species (e.g., Centrarchidae) would prosper from the zebra mussel invasion. We found that the median decrease in abundance of open-water species was 28%, whereas the median increase in abundance of littoral species was 97%. Populations of open-water species shifted downriver away from the zebra mussel population, whereas those of littoral species shifted upriver. Median apparent growth rates fell by 17% among open-water species and rose by 12% in the single littoral species studied. Many of the observed changes were large and involved species of commercial or recreational importance (e.g., American shad (Alosa sapidissima), black basses (Micropterus spp.)). The influence of zebra mussels on fish should vary widely across ecosystems as a function of system morphology, factors that limit primary production, and diets of the fish species.

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