Resource selection functions for age-0 Arctic grayling (Thymallus arcticus) and their application to stream habitat compensation

2004 ◽  
Vol 61 (9) ◽  
pp. 1736-1746 ◽  
Author(s):  
Nicholas E Jones ◽  
William M Tonn
Keyword(s):  
Habitat Use ◽  
Water Depth ◽  
Resource Selection ◽  
Productive Capacity ◽  
Resource Selection Functions ◽  
Arctic Grayling ◽  
Artificial Stream ◽  
Average Water ◽  
Thymallus Arcticus ◽  
Habitat Compensation

We developed resource selection functions (RSFs) for young-of-the-year (YOY) Arctic grayling (Thymallus arcticus) in a natural Barrenlands stream and used them to assess the habitat in an artificial stream created as part of a habitat compensation agreement in the Canadian Arctic. The model for small (15–21 mm) grayling explained 55% of the variation in habitat use and included water velocity, average water depth, and percentage of detritus and fines. The model for large (38–57 mm) grayling explained 36% of the variation in habitat use and included water depth, percentage of detritus and fines, and several cover variables. Model validation using a withheld sample of data indicated that the models provided good fits to the data, correctly classifying 71–75% of habitat-use locations. Applying the RSFs to observed habitat use in the artificial stream indicated an abundance of quality habitat for small grayling, but a paucity for the larger YOY. These results reflect an ontogenetic shift in habitat requirements, from the simple needs of small YOY to the more complex demands of larger YOY, demands that could not be well met by the artificial stream. We suggest that this inability contributed to the poor productive capacity of the artificial stream.

Productive capacity of an artificial stream in the Canadian Arctic: assessing the effectiveness of fish habitat compensation

2003 ◽  
Vol 60 (7) ◽  
pp. 849-863 ◽  
Author(s):  
Nicholas E Jones ◽  
William M Tonn ◽  
Garry J Scrimgeour ◽  
Chris Katopodis
Keyword(s):  
Fish Habitat ◽  
Physical Habitat ◽  
Productive Capacity ◽  
Average Mass ◽  
Arctic Grayling ◽  
Artificial Stream ◽  
Natural Streams ◽  
Explicit Analysis ◽  
Gains And Losses ◽  
Habitat Compensation

Few fish habitat compensation projects are assessed with respect to the principle of "no net loss" of productive capacity. Using reference streams as standards against which gains and losses of functions (e.g., production of fish) could be quantified, we examined the effectiveness of a 3.4-km artificial stream in the Northwest Territories, Canada. The artificial stream restored watershed connectivity, allowing fish migration and provided spawning and nursery habitat, particularly for Arctic grayling (Thymallus arcticus). However, the average mass of young-of-the-year (YOY) grayling at the end of summer was lower (57%) in the artificial stream than in natural streams. This difference in growth, in concert with estimates of grayling density, meant that the standing crop produced in the artificial stream averaged 37% of that found in natural streams. A bioenergetics model indicated that cooler water temperatures in the artificial stream had limited influence on growth. Instead, low amounts of autochthonous and allochthonous organic matter and poor physical habitat in the artificial stream appeared to limit the productivity of benthic invertebrates and fish. Our explicit analysis of productive capacity will allow future compensation measures to focus on deficiencies in the artificial stream and on the improvement of its productive capacity as fish habitat.

Rheotactic Differentiation between Fluvial and Lacustrine Populations of Arctic Grayling (Thymallus arcticus), and Implications for the Only Remaining Indigenous Population of Fluvial "Montana Grayling"

1991 ◽  
Vol 48 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Calvin M. Kaya
Keyword(s):  
Indigenous Population ◽  
Arctic Grayling ◽  
Artificial Stream ◽  
Light Intensities ◽  
Thymallus Arcticus ◽  
Permanent Stream

Rheotactic behavior of young Arctic grayling (Thymallus arcticus) from fluvial (Big Hole River) and lacustrine (Red Rocks Lake) populations in Montana was assessed in an artificial stream to see if fluvial grayling are adapted to life-long residence in streams by having an innately greater tendency to hold position and lesser tendency to go downstream. Responses of young tested at 0–10 d post-swimup contradicted the hypothesis; the fluvial grayling had strong downstream responses similar to or greater than those of the lacustrine grayling. When tested 18–31 d post-swimup, however, rheotactic responses of the fluvial and lacustrine grayling were consistent with the hypothesis, at three light intensities (full and dim lighting and darkness). Rheotactic differences were even greater in trials at 47–72 d post-swimup (conducted only under full lighting). Big Hole River grayling appear to be adapted to permanent stream residence. Such adaptation reinforces the importance of conserving this last indigenous fluvial population of the geographically disjunct, genetically identifiable "Montana grayling."

Position Choice by Drift-Feeding Salmonids: Model and Test for Arctic Grayling (Thymallus arcticus) in Subarctic Mountain Streams, Interior Alaska

1990 ◽  
Vol 47 (10) ◽  
pp. 2039-2048 ◽  
Author(s):  
Nicholas F. Hughes ◽  
Lawrence M. Dill
Keyword(s):  
Energy Intake ◽  
Water Depth ◽  
Focal Point ◽  
Water Velocity ◽  
Net Energy ◽  
Intake Rate ◽  
Arctic Grayling ◽  
Thymallus Arcticus ◽  
Net Energy Intake ◽  
Energy Intake Rate

We develop a model to predict position choice of drift-feeding stream salmonids, assuming a fish chooses the position that maximizes its net energy intake rate. The fish's habitat is represented as a series of stream cross-profiles, each divided into vertical strips characterized by water depth and velocity. The fish may select a focal point in any of these strips, and include several neighbouring strips in its foraging area. The number of prey the fish encounters depends on its reaction distance to prey, water depth, and water velocity; the proportion of detected prey the fish is able to capture declines with water velocity. The fish's net energy intake rate is its gross energy intake rate from feeding minus the swimming cost calculated by using water velocity at the fish's focal point. There was a close match between the positions predicted by this model and those chosen by solitary Arctic grayling (Thymallus arcticus) in the pools of a mountain stream in Alaska.

scholarly journals Using Video to Evaluate Depth and Velocity Selection by Arctic Grayling (Thymallus arcticus) in Pools of an Engineered Tundra Stream

ARCTIC ◽  
2019 ◽  
Vol 72 (2) ◽  
pp. 103-115
Author(s):  
Cody Kupferschmidt ◽  
Fred Noddin ◽  
David Z. Zhu ◽  
William M. Tonn
Keyword(s):  
Fish Passage ◽  
Background Flow ◽  
Monitoring Method ◽  
Spawning Period ◽  
Video Assessment ◽  
Arctic Grayling ◽  
Scour Holes ◽  
Thymallus Arcticus ◽  
Velocity Selection ◽  
Habitat Compensation

We evaluated pool use by Arctic grayling (Thymallus arcticus) in an engineered stream in the Canadian Barrenlands at the summer background flow (1.0 l/s) and at enhanced flows (9.9 l/s and 21.9 l/s) similar to those during the spring spawning period. We used an acoustic Doppler velocimeter to measure and map out point velocities (horizontal and vertical) in five study pools. The positions of adult Arctic grayling were monitored for each flow condition using visual surveys and a novel video assessment technique. Although fish mobility limited pool selection at the summer background flow, the highest use of pools by fish during enhanced flows occurred where pool designs incorporated scour holes or downstream sills to provide larger amounts of relatively deep water. Within those pools, grayling selected for locations with depths between 0.20 m and 0.30 m and near-zero vertical velocities (−0.02 m/s to 0.04 m/s). Fish selected near-zero horizontal velocities(0.00 m/s to 0.04 m/s) for resting and higher velocities (0.12 m/s to 0.20 m/s) for feeding. In contrast, grayling tended to show local avoidance of areas with horizontal velocities above 0.2 m/s or vertical velocities above 0.04 m/s. Although findings are likely site specific, our study contributes towards the development of size, depth, and velocity criteria for Arctic grayling habitat; this information can promote effective designs for habitat compensation and fish passage projects. We also present a novel video monitoring method that can be easily deployed at remote locations.

Resource selection by grazing herbivores on post-fire regrowth in a West African woodland savanna

2007 ◽  
Vol 34 (2) ◽  
pp. 77 ◽  
Author(s):  
Erik Klop ◽  
Janneke van Goethem ◽  
Hans H. de Iongh
Keyword(s):  
Resource Selection ◽  
West African ◽  
Tree Cover ◽  
Resource Selection Functions ◽  
Risk Of Predation ◽  
Savanna Fires ◽  
Grass Sward ◽  
Burnt Areas ◽  
Good Visibility ◽  
Selection Of

The preference of grazing herbivores to feed on grass regrowth following savanna fires rather than on unburnt grass swards is widely recognised. However, there is little information on which factors govern patterns of resource selection within burnt areas. In this study, we attempted to disentangle the effects of different habitat and grass sward characteristics on the utilisation of post-fire regrowth by nine species of ungulates in a fire-dominated woodland savanna in north Cameroon. We used resource-selection functions based on logistic regression. Overall, the resource-selection functions identified the time elapsed since burning as the most influential parameter in determining probability of use by ungulates, as most species strongly selected swards that were recently burned. This pattern might be related to nutrient levels in the grass sward. In addition, most species selected areas with high grass cover and avoided grass swards with high amounts of dead stem material. This is likely to increase bite mass and, hence, intake rates. The avoidance of high tree cover by some species may suggest selection for open areas with good visibility and, hence, reduced risk of predation. Body mass seemed to have no effect on differential selection of post-fire regrowth, irrespective of feeding style.

Process-focussed, multi-grain resource selection functions

2015 ◽  
Vol 305 ◽  
pp. 10-21 ◽  
Author(s):  
Michel P. Laforge ◽  
Eric Vander Wal ◽  
Ryan K. Brook ◽  
Erin M. Bayne ◽  
Philip D. McLoughlin
Keyword(s):  
Resource Selection ◽  
Resource Selection Functions
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