Enhancement of Oceanic Productivity through Application of Municipal Sewage

Abstract

While it is widely recognized that the application of sewage, treated sewage, or sewage sludge on agricultural land can be beneficial (primarily as a fertilizer), the disposal of these same materials in the ocean is typically viewed in a negative light. Yet, when sewage sludges and effluents are introduced in a properly controlled manner, they can be of benefit to large areas of the ocean. For example, benthic biomass and growth rates of commercially-valuable species have been shown to be stimulated by the input of sewage sludge and effluents into certain ocean areas. Increases in fish productivity have also been associated with these inputs. The application of sewage sludge may be particularly beneficial in those areas which are naturally nutrient-deficient. Further, the potential problems of effluent or sewage sludge application in the ocean are similar to, although probably less severe than, those encountered with land disposal (i.e., toxics, pathogens, and amount applied to a given area).