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Helgoland Marine Research

Open Access

Impact of power-plant discharges on marine zooplankton: A review of thermal, mechanical and biocidal effects

  • J. M. Capuzzo1
Helgoländer Meeresuntersuchungen33:BF02414767


The relative importance of thermal, mechanical and biocidal stresses to marine zooplankton entrained in cooling waters from coastal power-plant operations is dependent on specific features of power-plant design and siting. Toxic effects of power-plant operations will vary with (1) the degree of mechanical stress induced by pumping velocities of cooling water; (2) the physical and chemical interaction of receiving and discharge waters; (3) the dosage of chlorine or other biocide added to cooling waters for fouling control; (4) the exposure time to stress conditions experienced during passage through condenser conduits and discharge canals; and (5) the nature of receiving waters, affecting the production and availability of the various halogen toxicants formed upon chlorination of seawater. Because of these variables, the problem of entrainment-induced mortality of zooplankton and the resulting effects on secondary production in receiving waters is difficult to assess. A review of laboratory and field studies addressing these problems is presented and particular emphasis given to the synergistic effect of multiple stresses.