Biofouling and bioresistance of bamboo in marine environment
M V Rao, M Balaji, V Kuppusamy, K S Rao
Proudly known as “green gold” and popularly called as “poor man’s timber”, bamboo is closely interwoven with the life of scores of people around the globe because of its versatile qualities and desirable strength properties as a structural material. It is used for innumerable purposes both on land and in water including seas and brackishwater bodies. "Presently, bamboos constitute an important raw material, and are vital to the economy of many countries" (John et al, 1995). In the words of Hanke (1990), "it is difficult to exaggerate the importance of bamboo as a structural raw material for most of human kind". "The 500-plus species are scattered throughout the warmer parts of the world, but the family achieves greatest abundance and most impressive luxuriance around the southern and southeastern edge of Asia, from the Indian monsoon region through China and Japan to Korea". Annually, about 4.56 million tons of bamboo from 30 genera comprising of 136 species is exploited in India alone (Anonymous, 1989). A vast quantity of it is used in the marine sector as fishing rods, sail masts, stakenet poles, mariculture cages and poles, fishing screens, fishing net supports, fish traps, fish baskets, floats for nets, floating rafts, floating fenders, floating platforms, etc., right from conventional capture fisheries to the most modern mariculture operations (Purushotham, 1963, Suri and Chauhan, 1984 and Santhakumaran and Sawant, 1993). Use of 30 lakh culms of bamboo per year for strikingly large screens of up to 10 Km and several other devices was reported by Satyanarayana Rao et al (1992) from Kolleru Lake in Andhra Pradesh, India, where brackishwater conditions prevail during certain seasons/in certain pockets. Similarly, bamboo cages of varying dimensions from 4 x 4 x 5 m to 50 x 5 x 5 m are reported to be employed for open ocean culture of fishes in Kampuchea, Indonesia and Thailand (Nayak, 2001). In all these utilities, bamboo is mostly used in untreated form. Yet, precise data on biofouling and bioresistance of different species of bamboo under marine conditions are not available except for isolated reports like that of Santhakumaran and Sawant (1993). Therefore, studies in this direction were taken up. Initially three
widely used commercial Indian species of bamboo were tested and their performance is presented in this paper.