THE EFFECT OF RESUSPENSION ON ALGAL PRODUCTION IN A SHALLOW LAKE

Waves cause erosion and resuspension of bottom sediments. In shallow lakes resuspension can take place over most of the lake area and the resuspended matter can stay in suspension for such a long time that the mean light intensity in the lake is reduced, causing reduced algal growth. The increase of suspended matter and light attenuation in the water of lake Tamnaren, Sweden, was found to be proportional to wind velocity to the third power. After each storm increased attenuation of light lasted for a week. The algal production was estimated to be reduced to only 15% of what it would have been without increased turbidity due to resuspension.