Performance of different wood protection methods in tropical marine waters, krishnapatnam harbour, India

The performance of different wood protection methods viz., diffusion, double diffusion, sap displacement, boucherie and pressure process was assessed in tropical marine waters at Krishnapatnam harbour on the east coast of India. Among non-pressure processes, the diffusion process was the most effective against wood borers and results were similar to the pressure process, while other treatment methods were not effective in marine waters. Control logs were severely damaged within one year, while treated ones showed enhancement in the durability compared to controls by a factor of two to three times. Wood borer attack and fouling settlement on logs was recorded at regular intervals. In all, 9 species of borer's viz. Martesia striata, M. nairi, Teredo furcifera, T. fulleri, T. parksi, Lyrodus pedicellatus, Bankia campanellata, B. carinata and B. rochi were identified. Among these, M. striata, T. furcifera, L. pedicellatus and B. campanellata played an important role in damage of wooden logs. In the case of fouling organisms, barnacles, oysters and bryozoans were dominant groups, while other groups settled sporadically.