Exploratory limnological studies of lake Manapouri, South Island, New Zealand

Abstract

Bathymetric and thermometric surveys of Lake Manapouri show that the greatest depth is 444 m and that the major portion of the lake occupies depths greater than 150 m. Stratification has developed by January, remains until June, and is followed by near isothermal conditions in late winter. The water temperature below 200 m is between 7.77° and 8.0°c throughout the year. The surface water temperature varies between 16.25°c in January‐March, and 8.0°c in August‐September. Tritium values suggest mixing has taken place to at least 400 m. Coarse sediments taken in 431 m indicate that the deep floor of the lake is not completely dominated by muddy sediments.