Phytoplankton in the English Lakes: I. The Proportions in the Waters of Some Dissolved Substances of Biological Importance

Abstract

Periodic analyses of phosphate P, silica, Fe, carbonate hardness, albuminoid ammonia, Ca, and pH show variations in the waters of the 9 lakes investigated as follows: phosphate P 0.0007-0.020, nitrate 0.02-0.20, Fe 0.01-0.30, silica 0.1-2.4 (all in mgm. per litre), and pH 6.3-7.4, the values being normally lower in the summer months. On the basis of the summer values, the lakes fall into 2 groups: (1) with carbonate hardness 6-10, phosphate and silica high, pH below 6.9; it includes the rocky lakes Ennerdale, Crummock, Wastwater and Derwentwater; (2) with carbonate hardness 6-10 and over, phosphate and silica low, pH above 6.9; it includes the lakes with silted shores and soil-covered drainage systems, Bassenthwaite, Lowes Water, Windermere, Ullswater and Esthwaite.