Download or read book Exploring the Role of Temperature and Possible Alternative Stable States in Brook Trout Salvelinus Fontinalis Population Structure written by Brooke Lynn Hawkins and published by . This book was released on 2019 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most organisms undergo ontogenetic changes, leading to complex life histories. An organism’s prey and habitat preferences change as they age, as may their responses to the same environmental stressors. Therefore, a changing environment may confer a competitive advantage to a particular life stage, leading to population structures dominated by one stage or another. I used survey data of brook trout (Salvelinus fontinalis) in lakes across the Sierra Nevada to investigate if there was evidence for (1) alternative stable states between populations dominated by small or large fish, and (2) trends in population structure across elevation to suggest that temperature plays a key role in determining size structure. I characterized the average fish size, number of size classes, and the evenness of the size class distribution for 42 populations. I found these features by fitting a Bayesian normal mixture model using Markov Chain Monte Carlo simulations. I tested for alternative stable states by looking for bimodality in each feature, and I analyzed each feature’s relationship with elevation using Spearman’s rank correlation. I found that that populations are most often dominated by small individuals, rarely by large individuals, and most often contain either one or two distinct size classes. If large individual body sizes occur as an alternative population state, my results show that such populations occurred rarely, or were not well sampled by these surveys. High elevation was associated with reduced average size and greater numbers of size classes, suggesting that temperature does affect size distributions.
Download or read book Conservation Genetics of Remnant Anadromous Brook Trout Salvelinus Fontinalis Populations at the Southern Limit of Their Distribution written by Brendan J. Annett and published by . This book was released on 2005 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal Stratification of Dilute Lakes written by Carl L. Schofield and published by . This book was released on 1993 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Genetic Effect of Stocking and Population Structure of Brook Trout Salvelinus Fontinalis in the Beef River written by Kevin Callen and published by . This book was released on 1983 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal Stratification of Dilute Lakes written by and published by . This book was released on 1993 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Habitat Suitability Index Model for Brook Trout in Streams of the Southern Blue Ridge Province written by Christopher J. Schmitt and published by . This book was released on 1993 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetic Diversity and Population Structure of Brook Trout Salvelinus Fontinalis in a Remote Adirondack Watershed written by Spencer Bruce and published by . This book was released on 2014 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal Ecology of Brook Trout Salvelinus Fontinalis and Atlantic Salmon Salmo Salar in Impounded Streams microform Behavioural Responses and Population Impacts written by MacMillan, John L. (John Leland) and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 1999 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal Stratification of Dilute Lakes Evaluation of Regulatory Processes and Biological Effects Before and After Base Addition Effects on Brook Trout Habitat and Growth written by and published by . This book was released on 1993 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: We address the significance of changes in summer thermal stratification patterns of Adirondack lakes affected by acidification to cold-water fish populations inhabiting these sensitive lakes. The brook trout (Salvelinus fontinalis) is the primary cold-water fish species indigenous to acid-sensitive lakes in the Adirondack region of northern New York State; the ability of these lakes to sustain this important sport species is highly dependent on the availability of adequate summer habitat, consisting of cool, well-oxygenated water. We hypothesized that acidification-induced reductions in the thermal stability of sensitive Adirondack lakes could lead to degradation of potential brook trout habitat. We also hypothesized, on the basis of energetic considerations, that brook trout growth and average size at age would be sensitive indicators of differences in the extent and availability of preferred summer habitat in lakes with different thermal structures. These hypotheses were addressed in this study by utilizing data available from previous lake liming studies in the Adirondack region, brook trout growth data from management studies in the region, and the extensive Adirondack Lake Survey Corporation (ALSC) data base. We compared brook trout growth among lakes with known thermal stratification patterns; analyzed temporal changes in the extent and availability of preferred brook trout habitat, resulting from changes in acid or base status of limed Adirondack lakes; and applied a bioenergetic growth model for sensitivity analysis of temperature effects on simulated growth of brook trout populations inhabiting lakes with different thermal structures.
Download or read book Habitat Suitability Index Models written by Robert F. Raleigh and published by . This book was released on 1982 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessment and Predictive Model for Brook Trout Salvelinus Fontinalis Population Status in the Eastern United States written by and published by . This book was released on 2006 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Brook Trout Populations in Headwater Stream Networks written by Yoichiro Kanno and published by . This book was released on 2011 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessing Populations of Eastern Brook Trout Salvelinus Fontinalis Above and Below Waterfalls in Mountain Streams of Virginia written by and published by . This book was released on 2019 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anthropogenically driven factors, such as increasing temperature and sediment in valley streams, acidification of mountain streams, and the introduction of non-native trout, are restricting habitat suitable for healthy populations of eastern brook trout (Salvelinus fontinalis) throughout their native Appalachian range. Brook trout are important as predators of insects in mountain streams and as a favorite of anglers. It is crucial that remaining populations in sustainable habitats be identified and preserved. Waterfalls are geologic knickpoints preventing base-level lowering that create unique, stable landscapes above them, which may alleviate the temperature-productivity/acidity "habitat squeeze" for populations of brook trout and could serve as potentially ideal targets for conservation efforts despite being isolated. This study investigates brook trout occurrence above waterfalls in Virginia and compares brook trout populations found above waterfalls to those below them. One-hundred meter reaches above and below seven waterfalls in Virginia's George Washington and Jefferson National Forest were sampled for brook trout via 3-pass, block-netted, backpack electrofishing depletions. All brook trout were counted, weighed, and measured for fork length. The response variables are differences in 1) percent dominance, 2) population size, 3) biomass, and 4) length-weight index (Fulton's Condition Factor) between brook trout above and below waterfalls. Brook trout dominance (100 vs. 36.9%) is greater above than below waterfalls, but not significantly (p = 0.1003). We found abundance (26 vs.12 individuals per 100m) and overall biomass (885.3 vs 284.6 grams per 100m) of brook trout populations above waterfalls to be significantly greater than their below waterfall counterparts (p = 0.078 for both). We also found brook trout above waterfalls to have a higher condition factor (1.086g/cm3 vs 1.0636g/cm3) than those below waterfalls (p = 0.031). Lastly, we found populations above waterfalls where their occurrence was previously unknown. Despite being isolated, brook trout populations above waterfalls were just as if not more robust than those below and may be excellent targets for conservation.
Download or read book The Influence of Temperature and Discharge on Movement Patterns of Brook Trout Salvelinus Fontinalis in the Ford River Dickinson County Michigan written by Steven M. Marod and published by . This book was released on 1995 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Habitat Suitability Index Models and Instream Flow Suitability Curves written by Robert F. Raleigh and published by . This book was released on 1986 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spatial Variation in Brook Trout Salvelinus Fontinalis Population Dynamics and Juvenile Recruitment Potential in an Appalachian Watershed written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sensitivity and Exposure of Brook Trout Salvelinus Fontinalis Habitat to Climate Change written by and published by . This book was released on 2010 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: Predicting coldwater fisheries distributions under various climate scenarios is of interest to many fisheries managers and researchers. Larger scale models have been useful in highlighting the potential large scale threat. However, the error associated with these models makes predictions of the persistence of individual cold water fisheries problematic. Most of this error is associated with predicted air and water temperatures which typically are simple elevation and location (latitude/longitude) models with simple caveats such as 1°C increase in air temperature equals 0.8°C increase in water temperatures. I directly measured paired air and water temperatures in watersheds containing reproducing populations of brook trout in Virginia during the critical summer period (July 1 to September 30) in both 2009 and 2010. I developed a classification system using sensitivity (change in the daily maximum water temperature from a 1°C increase in the daily maximum air temperature) and exposure metrics (frequency; duration; and magnitude of daily maximum water temperatures> 21°C) that classified brook trout populations into four categories: High Sensitivity-High Exposure; High Sensitivity-Low Exposure; Low Sensitivity-High Exposure and Low Sensitivity- Low Exposure. I found that my paired air and water temperature relationships were highly variable among sites and were a useful metric for classifying the sensitivity and exposure of individual brook trout populations to various climate change scenarios. I identified many (25%) Low Sensitivity- Low Exposure brook trout populations that appear to be resilient to climate change. The median sensitivity (0.39°C) in this study was much lower than the assumed rate (0.80°C) used in many regional models that predicted a complete extirpation of brook trout in Virginia. Several GIS generated metrics (sample area; % riparian canopy; solar insolation ; % groundwater; elevation; % watershed in forest cover) were useful for predicting (accuracy approximately 75%) sensitivity and exposure values. Directly measuring paired air and water temperature relationships can reduce the error of large scale models. I recommend that managers making investment decisions in protecting and restoring brook trout use my direct measurement approach when they cannot afford to make a Type I or Type II error.
