Ecological studies of the surface microlayer of small ponds at the UWM Field Station

Abstract

The seasonal variation and enrichment of nutrients, pigments, bacteria, fungi and algae in the surface microlayer and subsurface waters were investigated in three ponds at the University of Wisconsin-Milwaukee Field Station, Saukville, Ozaukee County, Wisconsin. Samples were collected intermittently from June, 1978 through October, 1981. Microlayer samples were collected using a glass plate and a screen sampler. All ponds showed dramatic seasonal variations in nutrients, microorganisms and algae in both surface and subsurface waters. The data indicate that physical factors such as adsubble processes, antirain and atmospheric deposition, along with biological factors such as heterotrophic mineralization and autotrophic uptake, play significant roles in causing the enrichment or lack of enrichment of materials within the microlayer. Furthermore, this study suggests that surface microlayers, particularly in shallow environments where algal species are adapted to high light conditions. can be sites of high biological activity.