In a laboratory study evaluating the effectiveness of 10 commercial products in stimulating enhanced biodegradation of Alaska North Slope crude oil, two of the products provided significantly greater alkane degradation in closed flasks than indigenous Alaskan bacterial populations supplied only with excess nutrients. These two products, which were microbial in nature, were then taken to a Prince William Sound beach to determine if similar enhancements were achievable in the field. A randomized complete block experiment was designed in which four small plots consisting of a no-nutrient control, a mineral nutrient plot, and two plots receiving mineral nutrients plus the two products were laid out in random order on a beach in Prince William Sound that had been contaminated 16 months earlier from the Exxon Valdez spill. These four plots comprised a 'block' of treatments, each block being replicated four times on the same beach. Triplicate samples of beach sediment were collected at four time intervals and analyzed for oil residue weight and alkane hydrocarbon profile changes. The results indicated no significant differences among the four treatments in the 27-day time period of the experiment. (Copyright (c) 1992 Society for Industrial Microbiology.)