Marine Biofouling on Moored Buoys and Sensors in the Northern Indian Ocean

Equipment and structures deployed in seawater and other marine environments are susceptible to marine growth. This marine biofouling is one of the critical factors that affects the measurement of continuous real-time data from the oceanographic sensors deployed for long-term observations. To understand the characteristics of biofouling on marine sensors, an investigation was conducted on sensors deployed in a moored buoy network deployed and maintained by the National Institute of Ocean Technology (NIOT) in the Arabian Sea and Bay of Bengal regions. The present paper attempts to elucidate the characteristics of biofouling on sensor components deployed at seven locations in the Bay of Bengal and five locations in the Arabian Sea, at varying depths ranging from the surface to 500-m depth. Biofouling on bare sensor surfaces and surfaces with various antifouling measures has been studied for 2 consecutive years (2015 and 2016), and the effect of antifouling measures is discussed in this paper. Among the locations studied, buoys deployed in the Arabian Sea exhibited a higher biofouling load compared to the buoys deployed in the Bay of Bengal. The study showed that the pedunculate barnacles Lepas anatifera Linnaeus, 1758, was the predominant biofouling species on these sensors. Furthermore, observations show that the use of copper- and zinc-based antifouling methods reduced the incidence of biofouling by 59% on average.