Encrusters
Fouling organisms are aquatic organisms (marine and freshwater animals and plants) that settle on stone structures, submerged parts of ships, buoys, port and other hydraulic structures, internal surfaces of water systems, water intake pipes, underwater cables, etc., reducing ship speed, decreasing water flow in pipelines, lowering the efficiency of cooling devices, and promoting corrosion of metal and concrete underwater structures
Source: "GOST 26883-86 (CT SEV 5127-85). External Influencing Factors. Terms and Definitions"
(approved by the Decision of the State Standardization Committee of the USSR dated 29.04142)