THE REDUCTION OF FOOD RESOUCE INFLUX FOR FOULING ORGANISMS: POTENTIALS FOR MITIGATING BIOFOULINGS IN SEAWATER COOLING SYSTEMS OF POWER STATIONS

Abstract

 We evaluated the food resource supply for fouling organisms by inflows of suspended particulate organic matter (POM) in 18 cooling systems of 6 power stations based on seawater samplings and analysis of data from 71 cases of waste treatments of fouling organisms. As a result, the ratio of POM influx to the demand for the production of fouling organisms in the cooling systems ranged between 0.48 and 23.8 (3.55 in median) based on a general productivity/biomass ratio, and between 0.21 and 19.2 (1.99 in median) based on a general suspension-feeding rate of organisms. It was estimated that the areas of approximately several 10⁴ m² were necessary in the sea areas adjacent to the seawater intakes of the cooling systems to place facilities of suspensionfeeding oysters to remove the POM amounts equivalent to the supply or demand for the fouling organisms. The oyster-suspension approach would be difficult currently, since development of concensus among the stakeholders around the coasts are expected to be arduous. Further studies are necessary to examine whether this approach become more feasible by complex use of multiple ecosystem functions which are available in this approach.