Vertical distribution of herbivorous zooplankton in a well-mixed lake system in which the main predator is a non-selective filter-feeding fish

Abstract

The vertical distribution of herbivorous zooplankton was examined over a 24-hr period in Lake Somerville, Texas, a shallow, well-mixed, warrn-water reservoir in which temperature and oxygen gradients rarely occur. While no consistent preference for surface or bottom water was found, diel zooplankton population deficits were observed. Activity of the main planktivore, the non-visual, filter feeding gizzard shad, did not correspond to observed trends for zooplankton. Other factors such as sinking and resuspension of phytoplankton might have been important. © 2003, Copyright Taylor & Francis Group, LLC.