Thermal Stratification Of Dilute Lakes PDF Download

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.