The Exxon Valdez oil spill revisited and the dangers of normative science

In the July 2006 issue of Integrated Environmental Assessment and Management, a paper by Harwell and Gentile was published assessing the present ecological significance of the impacts from the Exxon Valdez oil spill (EVOS). First, this paper compares the major conclusions of Harwell and Gentile and a paper reviewing the current impacts of EVOS by Peterson et al as published by Science in 2003. Stark differences exist between the conclusions of the 2 papers regarding continuing impacts. Part of the difference appears to be the infusion of different social values or policy goals into each. Normative science is the use or interpretation of data in support of specific values or policies. Examples of values or policies intertwined with science are constructs such as ecosystem health, ecosystem integrity, ecological significance, and recovery. Examination of the environmental risk assessment and toxicology literature reveals that the symptoms of normative science are common and the implications widespread. Separation of science from policy or at a minimum a transparent acknowledgment of the science-policy interaction is clearly necessary in order to obtain a clear picture of the ecological system under investigation.