The sea off Ikitsuki I., Nagasaki Prefecture, Japan, has been the site of tests of tidal current power generation using turbines actuated by water flow. Such turbines are likely to be fouled by various benthic organisms. For about 8 months we conducted a biofouling study of model turbines, using an array of simple three-blade propellers mounted in a stainless steel frame set at a depth of 7 m on the sea bottom off Ikitsuki I. to check the effects of propeller rotation and anti-fouling paint on the accumulation of fouling organisms. Significant biofouling, up to 30–40 kg/m² in total and notably dominated by clumps of the barnacle Megabalanus rosa, occurred on both the frame and unpainted propellers, whether the latter were rotating or not. However, on propeller blades coated with anti-fouling paint, only a biofilm, and no macro-fouling, was observed. Such paint may also prove useful in preventing massive fouling of turbines used for tidal current power generation.

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