A site study of the multiple effects of thermal releases on the aquatic life in an estuarine area

The estuarine area of a river represents a typical site where different factors have to be considered when trying to assess the actual impact on the aquatic life of industrial thermal releases. These factors may be physical (river flow, sea currents, tides, residence time of waters in marshes and lagoons), biological (bio-mass production, mutual organic matter exchange between fresh and sea waters) and economic such as the commercial importance of fishing. In this respect the siting of a large power station in the Po river delta may cause serious problems for the conservation of the existing ecosystem. Thus a multidisciplinary approach with a view to predicting the final thermal impact of a power station on the environment seems fully justified despite its complexity. Therefore a detailed research programme has been established in order to study the following main points: (a) structure of the plant and animal populations; (b) primary production and bacterial activity; (c) physical and chemical characteristics of estuarine waters; (d) coastal characterization; (e) thermal effects on the biocenosis entering the condenser of existing plants operating under similar conditions. Together with conventional experimental techniques, airborne infra-red (IR) and multi-spectra (MS) surveys are planned as, according to preliminary investigations, they provide essential information for the recognition of water flow patterns and aquatic plant growth. The behaviour of the particular ecosystem will be simulated using mathematical models defined on a system theory approach, where the descriptive functions and rate constants come from experimental studies conducted in situ and with laboratory tests. In fact results of preliminary airborne scanning IR and MS surveys combined with biological studies confirm the need for systematic research on the Po river delta. (author)