The Key West study was undertaken to determine the impact of the discharge from a large desalting plant on the surrounding environment. The Phase-I work has shown that some of the properties of the effluent can be detected by physical and chemical measurements well beyond the area that visible effects can be detected in the bottom communities. While the effluent produces some beneficial effects such as attracting certain species of fish and the stone crab, Menippe mercenaria, it has also been shown to have deleterious effects for other organisms. Algae, tunicates, and gastropods were excluded from the near-field of the effluent discharge and bryozoan colonies were not as numerous in the discharge area nor did they grow as well as they did outside of the area. Quantitative investigations of the physiological and ecological effects of the desalting plant effluent in future studies could lead to predictive capabilities as far as the amount of environmental stress that can be tolerated at a given locality. (Author)