Predictive modeling and spatial mapping of fish distributions in small streams of the Canadian Rocky Mountain foothills

2008 ◽  
Vol 65 (2) ◽  
pp. 319-333 ◽  
Author(s):  
Richard J McCleary ◽  
Marwan A Hassan
Keyword(s):  
Land Use ◽  
Rainbow Trout ◽  
Brook Trout ◽  
Resource Selection ◽  
Fish Habitat ◽  
Rocky Mountain ◽  
Selection Function ◽  
Bull Trout ◽  
Automated Method ◽  
Small Streams

We developed an automated procedure for modeling spatial distribution of fish occurrence using logistic regression models and geographic information system (GIS) tools. Predictors were measured from a digital elevation model (DEM) and stream layers. We evaluated the accuracy of GIS measures of reach slope through a comparison with field measures. Resource selection function models were used to explain presence-absence of bull trout (Salvelinus confluentus), rainbow trout, (Oncorhynchus mykiss), nonnative brook trout (Salvelinus fontinalis), and all fishes. Our models were extrapolated based on low, medium, and high levels of probability to produce reach-scale maps across 12 000 km2. We attempted to improve models by adding land-use variables; however, the terrain best suited to road building and harvest also contained the habitat selected by rainbow trout, whereas bull trout generally selected terrain too steep for land use. These confounding factors emphasize the need for process-based investigations in addition to correlative approaches to identify habitat requirements. This automated method provides a rapid evaluation of fish habitat across remote areas useful for salmonid conservation and research planning.

Spatial patterns in relations among brown trout (Salmo trutta) distribution, summer air temperature, and stream size in Rocky Mountain streams

1999 ◽  
Vol 56 (S1) ◽  
pp. 43-51 ◽  
Author(s):  
Frank J Rahel ◽  
Nathan P Nibbelink
Keyword(s):  
Spatial Patterns ◽  
Air Temperature ◽  
Brown Trout ◽  
Brook Trout ◽  
Salmo Trutta ◽  
Rocky Mountain ◽  
Thermal Window ◽  
Small Streams ◽  
Brown Trout Salmo Trutta ◽  
Stream Size

Stream size interacted with mean July air temperature to influence the distribution of brown trout (Salmo trutta) in southeastern Wyoming streams. The geographic range of brown trout was positively associated with mean July air temperatures of 19-22°C. Within this thermal zone, brown trout were more likely to occur in large streams (>4 m wetted width) than in small streams. We used a geographic information system to examine spatial patterns in the distribution of anomalous sites (i.e., sites predicted to have brown trout but which lacked this species). Sites that lacked brown trout but contained brook trout (Salvelinus fontinalis) tended to be on small streams at the cold margin of the 19-22°C thermal window. Sites lacking both brown trout and brook trout tended to be on small streams clustered in three of the six study drainages. The spatial aggregation of these sites suggests that additional regional factors influence the occurrence of brown trout in southeastern Wyoming. It is hypothesized that these factors could involve land-use practices interacting with basin geology and geomorphology. Classification models that incorporate a few general habitat factors are useful for identifying stream reaches with the potential to support brown trout and for directing management efforts to sites where this potential is not realized.

Philonema agubernaculum sp.nov. (Dracunculidae), a Nematode from the Body Cavity of Fishes

Parasitology ◽  
1936 ◽  
Vol 28 (3) ◽  
pp. 440-442 ◽  
Author(s):  
James R. Simon ◽  
Felix Simon
Keyword(s):  
United States ◽  
Rainbow Trout ◽  
Brook Trout ◽  
Rocky Mountain ◽  
The United States ◽  
Body Cavity ◽  
The Body ◽  
United States Bureau ◽  
Pathological Changes

The nematode described here was collected by the Wyoming field party of the United States Bureau of Fisheries during the summer of 1934. The Rocky Mountain whitefish, the Eastern Brook trout, and the rainbow trout serve as hosts for the parasite. In several instances pathological changes, particularly of the gonads, were found to accompany its presence.

scholarly journals Estimating a resource selection function with line transect sampling

2002 ◽  
Vol 6 (4) ◽  
pp. 213-228 ◽  
Author(s):  
Bryan F. J. Manly
Keyword(s):  
Resource Selection ◽  
Probability Function ◽  
Resource Selection Function ◽  
Line Transect ◽  
Selection Function ◽  
Line Transect Sampling ◽  
Selection Probability ◽  
Transect Sampling ◽  
Conditional Maximum ◽  
Habitat Variables

A resource selection probability function is a function that gives the prob- ability that a resource unit (e.g., a plot of land) that is described by a set of habitat variables X1 to Xp will be used by an animal or group of animals in a certain period of time. The estimation of a resource selection function is usually based on the comparison of a sample of resource units used by an animal with a sample of the resource units that were available for use, with both samples being assumed to be effectively randomly selected from the relevant populations. In this paper the possibility of using a modified sampling scheme is examined, with the used units obtained by line transect sampling. A logistic regression type of model is proposed, with estimation by conditional maximum likelihood. A simulation study indicates that the proposed method should be useful in practice.

Food Specialization By Individual Trout

1972 ◽  
Vol 29 (11) ◽  
pp. 1615-1624 ◽  
Author(s):  
James E. Bryan ◽  
P. A. Larkin
Keyword(s):  
Rainbow Trout ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Stomach Contents ◽  
Cutthroat Trout ◽  
Salmo Gairdneri ◽  
Potential Prey ◽  
Repeated Observation ◽  
Size Growth ◽  
Salmo Clarki

Analyses of stomach contents showed that the kinds of prey eaten by brook trout (Salvelinus fontinalis), cutthroat trout (Salmo clarki), and rainbow trout (Salmo gairdneri) were seldom distributed at random among the individuals. Repeated observation of food eaten by individuals in a stream and ponds showed that prey types were eaten in proportions which were characteristic for an individual.Specialization occurred on several different kinds of prey. Although the degree of specialization was higher during shorter intervals, the data suggested that some specialization persisted for half a year. There were no striking correlations between degree of specialization and other individual properties such as size, growth rate, weight of food, number of food items, previous specialization, or area of recapture.In addition to the observations on trout in relatively undisturbed habitats, a field experiment was conducted using laboratory-reared rainbow trout held in small ponds. The food of each trout in the experiment was sampled repeatedly. In analysis of variance, interaction among the individuals and kinds of prey eaten showed that food specialization occurred. Both the absolute and relative abundance of potential prey were constant during the experiment.

Temperature and Competition between Bull Trout and Brook Trout: A Test of the Elevation Refuge Hypothesis

2007 ◽  
Vol 136 (5) ◽  
pp. 1313-1326 ◽  
Author(s):  
Thomas E. McMahon ◽  
Alexander V. Zale ◽  
Frederic T. Barrows ◽  
Jason H. Selong ◽  
Robert J. Danehy
Keyword(s):  
Brook Trout ◽  
Bull Trout

Aeromonas salmonicida: Relationship between Extracellular Growth Products and Isolate Virulence

1981 ◽  
Vol 38 (11) ◽  
pp. 1322-1326 ◽  
Author(s):  
Rocco C. Cipriano ◽  
Billy R. Griffin ◽  
Burton C. Lidgerding
Keyword(s):  
Rainbow Trout ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Aeromonas Salmonicida ◽  
Salmo Gairdneri ◽  
Lesion Development ◽  
Culture Supernatants ◽  
Crude Material

Extracellular growth products, extracted from culture supernatants of Aeromonas salmonicida by precipitation with ammonium sulfate and ethanol, were resolved into four fractions by ion-exchange chromatography. Although one of these (fraction II) possessed leukocytolytic activity, virulence of the pathogen was not associated with leukocytotoxicity. A positive correlation was established, however, between virulence and the toxicity of extracted material to cultured rainbow trout gonad (RTG-2) cells. The crude material and fractions II and III from virulent isolates were more toxic to RTG-2 cells than were similar preparations from avirulent isolates. Preparations from virulent isolates caused hemorrhaging, lesion development, and mortality when injected intramuscularly into brook trout (Salvelinus fontinalis) and Atlantic salmon (Salmo solar). Rainbow trout (Salmo gairdneri) were more resistant and lesions could be produced only with fraction II. Fraction II also possessed proteolytic activity.Key words: Aeromonas salmonicida, furunculosis, pathogenicity, salmonids, extracellular products, cytotoxicity, leukocytolysis, proteolysis, fishes

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