Copepod mortality induced by fluctuating levels of natural ultraviolet radiation simulating vertical water mixing

Abstract

The effect of fluctuating ultraviolet radiation levels on the copepod Boeckella gracilipes was investigated in Lake Escondido (Patagonia, Argentina). The animals were incubated either at fixed depths or rotating in in situ plankton wheels of different diameters. The observed mortality was significantly higher in rotating treatments. Static incubations can be used to predict the mortality of vertically moving B. gracilipes, providing that the doses of UVA and UVB are known. The results suggest that under moderate wind conditions, the plankton of shallow lakes are exposed to potentially damaging levels of solar radiation, even in relatively turbid waters.