The role of DOC in protecting freshwaters subjected to climatic warming and acidification from UV exposure

Abstract

Dissolved organic carbon (DOC) is known to play a primary role in protecting freshwater organisms from exposure to UV radiation (Scully and Lean 1994). Recent observations in lakes subjected to acidification with strong acids, and to climatic warming and drought have revealed that both perturbations cause DOC to decline, suggesting that climatic warming and acidification were jeopardizing freshwater ecosystems by allowing increasing UV exposure of freshwater communities (Schindler et al. 1996a, b; Yan et al. 1996; Williamson etal. 1996). From November 4-7, 1994, a small group of freshwater and marine scientists from Canada, the USA and Europe met at the Palisades Center in Jasper National Park, Alberta, Canada, to compare results of their studies of DOC-UV interactions and DOC budgets and characteristics in different regions. Environment Canada and the University of Alberta funded the workshop, which was hosted by Parks Canada. This volume contains a group of papers based on freshwater presentations at the workshop. Here, we present a brief overview of the papers, other recently published studies in this rapidly developing field, and their implications for freshwater ecosystems.