Thermal stratification of dilute lakes - evaluation of regulatory processes and biological effects before and after base addition: effects on brook trout habitat and growth

Addresses the significance of changes in summer thermal stratification patterns of Adirondack lakes affected by acidification to cold-water fish populations inhabiting these sensitive lakes. Brook trout Salvelinus fontinalis is the primary cold-water fish species indigenous to acid-sensitive lakes in the Adirondack region of N 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. Brook trout populations presently most susceptible to negative effects from acidification-induced increases in transparency and consequent reductions in preferred thermal habitat occur primarily in shallow, low-color lakes that are marginally acidified and either weakly stratified or strongly stratified with anoxic hypolimnia. Significant improvements in brook trout thermal habitat could be achieved in these lakes by reducing acidity levels, eg by liming.