This paper considers the ways in which news values shape the reporting of oil spills and the constraints under which media practitioners work. A series of oil spills since the late 1960s [including the Torrey Canyon (1967), the Exxon Valdez (1989), and the Sea Empress (1996)] have attracted considerable attention from the news media. The focus is upon the dynamics through which news sources, with their own particular vested interests, compete to secure representation of the issues. Media discourse on risk and the environment is, to a significant extent, a discourse dependent upon the voices of official "experts". Environmental organizations, industry, scientists and government offer their own particular competing accounts of the "reality" of the situation. Issues concerning differential access to the news media are crucial when considering who comes to define the event. Accordingly, the article examines the strategies adopted by the various news sources involved in influencing the symbolic representation of public issues. Media practitioners are faced with great problems in interpreting and explaining these competing claims. Relatively few journalists and broadcasters have a scientific training and perhaps one of the greatest problems is that by simplifying complex scientific information one inevitably distorts it. Frequently researchers make the assumption that it is possible to demonstrate a direct causal link between news media coverage and public attitudes. However, the paper calls for great caution in interpreting "public opinion" concerning environmental issues and concludes by arguing that news media representations may more usefully be viewed as the outcome of a battle among a selective range of news sources, each seeking to provide their own definition of the public representation of the issues. (C) 2002 Elsevier Science Ltd. All rights reserved.